AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Acknowledgments
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Background

Bronchial adenoma is a descriptive but misleading term for a diverse group of respiratory tract neoplasms that arise beneath the bronchial epithelium or in bronchial glands. They are characterized by a clinical course that is usually more benign than that of bronchogenic carcinoma. Three types make up approximately 95% of bronchial adenomas. Carcinoids (2 types of bronchial neuroendocrine tumors) account for 85% of bronchial gland tumors and 1-2% of all lung malignancies. Adenoid cystic carcinoma (cylindroma) most commonly arises in a salivary gland and accounts for 10% of bronchial adenomas. Of all bronchial gland tumors, 1-5% (and 0.1-02% of all lung tumors) are mucoepidermoid carcinoma. The common bronchial gland adenoma is the truly benign mucous gland adenoma. Additional mesodermal lesions and other lesions can arise in the tracheobronchial tree.
 
Laennec described a bronchial carcinoid in 1831. In 1907, Oberndorfer introduced the term  karcinoide to indicate “resembles carcinoma.” In 1930, Kramer grouped bronchial carcinoids and cylindromas as bronchial adenomas because of their better prognosis and less aggressive behavior compared with bronchogenic carcinoma. Mucoepidermoid tumors were described in 1952. In 1972, Arrigoni identified a more aggressive subset of carcinoids and classified them as atypical carcinoids, as opposed to the less aggressive typical carcinoids. Bronchial carcinoids are part of a spectrum of neuroendocrine tumors (see below), of which only the first 2 are considered bronchial adenomas. 
 
Bronchial neuroendocrine tumors, including tumor type and level of malignancy, are as follows:

• Typical carcinoid (Kulchitsky type I) - (+) 
• Atypical carcinoid (Kulchitsky type II) - (++) 
• Large cell neuroendocrine carcinoma - (+++) 
• Small cell carcinoma (Kulchitsky type III) - (++++) 

Treatment is surgical, often using conservative techniques. In 1932, Bigger performed the first bronchoplastic procedure, a bronchotomy for removal of a left mainstem endobronchial lesion. In 1939, Eloesser performed a bronchotomy with simple excision and fulguration of an adenoma of a left lower lobe orifice. In 1947, Price-Thomas performed the first sleeve resection for an adenoma originating in the right mainstem bronchus.

Etiology

Bronchial carcinoids are thought to arise from Kulchitsky cells. These neuroendocrine cells, formerly classified as amine precursor uptake and decarboxylation cells, produce and store biogenic amines and peptides. Typical carcinoids originate as clusters of monotonous polyhedral cells in a fibrovascular stroma. Ultrastructurally and immunoreactively, carcinoids share characteristics with small cell neuroendocrine carcinoma of the lung. 

Adenoid cystic carcinoma originates from salivary gland tissue. Occasionally, some tumor cells in this variant are of myoepithelial origin. These tumors have several other names, including cylindromas, adenoid cystic basal cell carcinomas, adenomyoepitheliomas, and pseudoadenomatous basal cell carcinomas.
 
Mucoepidermoid carcinomas originate from tracheal and proximal bronchi. These tumors are of squamous and intermediate elements, with intercellular bridges. They have the same microscopic appearance as mucoepidermoid carcinoma of the salivary glands, arise in glandular submucosa, and manifest as submucosal lesions. 
 
Mucous gland adenomas (ie, bronchial cysts, papillary cystadenomas) are rare submucosal tumors arising from mucous glands and truly are benign tumors.

Pathophysiology

Symptoms develop from the growth of the tumors within the tracheobronchial tree, with consequent obstruction leading to atelectasis or pneumonia.
 
Adenoid cystic carcinoma behaves very similar to major and minor salivary gland tumors. An important aspect of these tumors is that they tend to spread in a submucosal plane along the perineural lymphatics, beyond the obvious endoluminal margins of the tumor. Most do not metastasize; however, total excision by tracheal resection or tracheobronchial resection is not always possible because of extensive submucosal spread, and local recurrence remains a possibility.

Tumor location

• Carcinoid
• • Lobar or segmental location - Approximately 60%
  • Main bronchus - Approximately 20%
  • Peripheral - Approximately 20%
  • Carinal or tracheal – Infrequent
  • Multiple sites – Rare
• Adenoid cystic carcinoma – Predilection for trachea
• Mucoepidermoid carcinoma – Usually proximal bronchi and may be more common on the left side of the tracheobronchial tree 

Paraneoplastic involvement

Endocrinopathies associated with bronchial carcinoids include Cushing syndrome (with increased corticotropin levels), hyperpigmentation (excess melanocyte-stimulating hormone), syndrome of inappropriate excretion of antidiuretic hormone, and hypoglycemia. In addition, bronchial carcinoids may be associated with multiple endocrine neoplasia syndrome in up to 4% of patients, the majority of whom are female.
 
Carcinoid syndrome is a clinical entity that includes cardiovascular, gastrointestinal, respiratory, and cutaneous manifestations. Carcinoid syndrome occurs most commonly when gastrointestinal carcinoids metastasize to the liver and less frequently when due to bronchial carcinoids. Serotonin seems to play a major role in the manifestations of carcinoid syndrome. When released into the blood stream from gastrointestinal carcinoids, serotonin is broken down in the liver. However, in the presence of liver metastasis, serotonin has a diminished opportunity to be exposed to hepatic metabolism.

Bronchial carcinoids seem to produce diminished amounts of serotonin, and carcinoid syndrome is uncommon; however, when it does occur as a result of a bronchial carcinoid, it may be unusually severe. Carcinoid syndrome can be associated with cardiac valvular fibrotic lesions. These are usually on the right side when the syndrome is due to hepatic metastases, but they may be on the left side in the presence of a right-to-left cardiac shunt or carcinoid syndrome due to a bronchial carcinoid.
 
Cushing syndrome occurs in less than 1% of patients with bronchial carcinoid, but it still is the second most common paraneoplastic syndrome. An occult bronchial carcinoid should be sought in a patient with Cushing syndrome and no evident adrenal or pituitary source. Cushing syndrome due to bronchial carcinoids is most often the result of peripherally located tumors, many of which may be radiographically occult. Carcinoid metastases maintain a corticotropin hypersecretory status despite resection of the primary tumor.

Frequency

United States

• Bronchial adenomas represent 1-3% of pulmonary malignancies.
• Carcinoids account for approximately 85% of bronchial adenomas and 1-2% of all lung malignancies.
• Approximately 72% of bronchial carcinoids are typical and 28% are atypical.
• Adenoid cystic carcinomas account for 10% of bronchial adenomas.
• Mucoepidermoid carcinomas account for 1-5%.

International

• Bronchial adenomas are uncommon in all countries, and carcinoids represent the great majority. The pattern of symptoms and treatments are similar to those seen in the United States.

Mortality/Morbidity

• The overall 5-year patient survival rate for bronchial adenomas is 96%.
• Long-term follow-up reports reveal little evidence of local recurrence or distant metastases after complete resection. 
• Mucoepidermoid carcinoma occasionally results in intracranial metastases, even in cases with minimal bronchial wall involvement.

Race

• The racial distribution is equal, as far as can be determined for these uncommon tumors.

Sex

• Men and women are equally affected.

Age

• The prevalence is highest in persons aged 30-50 years, and the mean age at presentation is 43 years. The incidence is similar for all types of primary bronchial adenomas.

• Persons of any age can be affected. The median age at presentation is 45 years for typical carcinoids and 55 years for atypical carcinoids.

• While adenoid cystic carcinoma affects persons of any age, the metastatic variety tends to occur in younger persons.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Acknowledgments
• References

History

Up to 60% of patients have no symptoms. This is more likely if the adenoma is located peripherally as opposed to proximally. When present, symptoms are related to the presence and degree of endobronchial occlusion and the vascularity of the tumor. Hemoptysis occurs in 18%, recurrent infection or cough in 17%, dyspnea or wheezing in 2%, and carcinoid syndrome in 1%. 

• Endobronchial symptoms
• • Classic triad of cough, hemoptysis, and recurrent infection
  • Dyspnea
  • Wheezing and stridor
  • Sputum production
  • Pneumonia 
• Mediastinal involvement
• • Hoarseness due to recurrent laryngeal nerve involvement
  • Chylothorax due to thoracic duct involvement
  • Chest pain 
• Systemic
• • Endocrinopathies
  • Unexplained weight loss
  • Low-grade temperature elevation
• Classic triad of symptoms
• • Cough
  • Hemoptysis
  • Recurrent infection

Physical

Physical examination generally is unrevealing, but subtle findings may provide clues. In addition, the physical examination may help in finding other confounding disease processes.

• Upper airway obstruction - Stridor/wheezing
• • Lower airway obstruction
  • Asymmetric breath sounds
  • Postobstructive processes
• Respiratory insufficiency
• • Dyspnea
  • Increased work of breathing
  • Retractions
  • Orthopnea
  • Cyanosis
• Extrapulmonary manifestations - May include mechanical compressive and obstructive syndromes
• • Pancoast tumor - Superior sulcus tumor causing pain (eg, shoulder, forearm, arm, scapula), Horner syndrome, and atrophy of upper extremity musculature
  • Acute spinal cord compression – Paraplegia, sensory deficits, urinary retention/incontinence, and vertebral pain
  • Superior vena cava syndrome – Head congestion/fullness; headache; nasal congestion; dyspnea; cough; orthopnea; dilated veins in the upper extremity, neck, and face; upper extremity and facial edema; papilledema; facial cyanosis; and mental status changes

Causes

Bronchial carcinoids are thought to arise from Kulchitsky cells. These neuroendocrine cells, formerly classified as amine precursor uptake and decarboxylation cells, produce and store biogenic amines and peptides. Typical carcinoids originate as clusters of monotonous polyhedral cells in a fibrovascular stroma. Ultrastructurally and immunoreactively, carcinoids share characteristics with small cell neuroendocrine carcinoma of the lung.

Adenoid cystic carcinoma originates from salivary gland tissue. Occasionally, some tumor cells in this variant are of myoepithelial origin. These tumors have several other names, including cylindromas, adenoid cystic basal cell carcinomas, adenomyoepitheliomas, and pseudoadenomatous basal cell carcinomas.
 
Mucoepidermoid carcinomas originate from tracheal and proximal bronchi. These tumors are of squamous and intermediate elements, with intercellular bridges. They have the same microscopic appearance as mucoepidermoid carcinoma of the salivary glands, arise in glandular submucosa, and manifest as submucosal lesions.
 
Mucous gland adenomas (ie, bronchial cysts, papillary cystadenomas) are rare submucosal tumors arising from mucous glands and truly are benign tumors.

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Other Problems to be Considered

Adenocarcinoma of the lung
Large cell lung cancer
Squamous cell lung cancer
Carcinoid
Mucoepidermoid carcinoma
Adenoid cystic carcinoma
Granuloma
Hamartoma
Metastatic cancer

Aspergillosis: This may occur in association with malignant disorders. Uncommonly, it accompanies benign carcinoid and can lead to a delay in diagnosis of the adenoma.

Recurrent lobar pneumonia: Consider primary endobronchial tumor as the etiology, especially in children.

Asthma: Asthma can be an early cause of misdiagnosis, a common error with obstructing tracheobronchial lesions.

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Lab Studies

No single investigative method is adequate to diagnose bronchial tumors in all patients, but most tumors are detectable. Laboratory, radiographic, and procedural techniques are required to locate lesions.

• Complete blood cell count
• • Not diagnostic but can help in differentiation of an infiltrate as a pneumonia
  • Useful to help quantify volume of hemoptysis associated with endobronchial lesions
• Electrolyte, BUN, creatinine, and calcium values: These values are not particularly helpful, but the results may assist in the evaluation of paraneoplastic involvement.
• Liver function tests: Results are insensitive as indicators of hepatic metastases.
• Arterial blood gas determination: This is useful for the detection of respiratory failure (eg, acidosis, hypercarbia, hypoxia).
• Sputum culture and cytology
• • Rarely helpful in diagnosing bronchial adenomas
  • Sensitivity of approximately 74% if central airways are involved
• Tumor markers
• • Corticotropin
  • Antidiuretic hormone
  • Calcitonin
  • Bombesin
  • Neuron-specific enolase
  • Serotonin
  • Synaptophysin
  • Note: All the above-mentioned markers also can be identified in small cell lung cancer; therefore, their presence offers no diagnostic value in distinguishing between these 2 tumor types. 
• Biochemical testing: Neither blood screening nor urine screening for serotonin or 5-hydroxyindoleacetic acid is of diagnostic value, unless carcinoid syndrome is clinically present. If it is, the presence of these biochemical abnormalities portends a more adverse prognosis.
• Immunohistochemical staining: This may help detect differences in secretory products between typical carcinoids and others.

Imaging Studies

• Chest radiography
• • Films may demonstrate a nodule, mass, infiltrate, mediastinal or hilar lymphadenopathy, or pleural effusion.
  • Findings may be due to bronchial obstruction.
  • Radiological findings are frequently nondiagnostic.
  • Oblique-view radiographs provide improved detectability of central lesions and may delineate an occult endobronchial component. 
• Computed tomography scanning
• • CT scanning is the best imaging modality.
  • Upon nodule discovery, obtain 10-mm CT cuts through the chest and upper abdomen. Fine cuts (eg, 1- to 2-mm) should be obtained through nodules, looking for calcifications. Tracheobronchial obstruction is suggested by compression of structures in close proximity to the trachea on the chest CT scan. Three-dimensional reconstruction may aid in localization of endobronchial tumors. 
  • CT scanning further delineates endobronchial and parenchymal tumor components. Prior to the development of CT scanning, tomography and bronchography were used to delineate endobronchial obstruction and bronchiectasis distal to the mass. CT scanning supplants both of these tests; neither is currently indicated. 
  • Central lesions are observed as well-defined masses that narrow, deform, or obstruct adjacent airways. Diffuse punctuate calcifications are observed in 30% of cases and are characteristic but not diagnostic of carcinoid. 
  • Peripheral parenchymal atelectasis or bronchiectasis is common. 
  • Peripherally located lesions are contiguous with the airway. 
  • Typical carcinoid is marked by homogeneous contrast enhancement.
  • Atypical carcinoid is associated with less contrast enhancement and frequent irregular contours; regional adenopathy is common. 
  • Stromal osseous metaplasia due to tumor-induced necrosis of bronchial cartilage is observed on CT scans as intratumoral calcification.
• Magnetic resonance imaging: This is probably most often used when CT scan findings are equivocal.
• Positron emission tomography: The positron emission tomography (PET) tracer F-18-fluorodeoxyglucose (FDG) has been used to detect bronchogenic carcinoma. Because of their low metabolic rate, carcinoid tumors usually do not "light up" with PET-FDG scanning.
• Radiolabeled peptides: Because carcinoid tumors, like other neuroendocrine tumors, may contain somatostatin receptors, the radiolabeled peptides may be useful. The 2 reported to be of greatest merit are [(111In0-DPTA(0)] octreotide (Octreoscan, Mallinckrodt; Petten, The Netherlands) and 99m technetium Tc depreotide single-photon emission CT scanning (NeoTect, Diatide; Londonderry, NH).
• Nuclear imaging: This can include bone scanning when applicable.

Other Tests

• Spirometry: Peak expiratory flow is a good bedside detector of significant airflow obstruction. Flow volume loops indicate truncation of the expiratory limb.

Procedures

• Transbronchoscopic fine-needle aspiration
• • Fine-needle aspiration (FNA) biopsy of peripheral lesions may yield a basis for diagnosis, including revision of incorrect interpretations (eg, bronchial carcinoid misinterpreted as small cell carcinoma); therefore, histologic confirmation is the only definitive means of diagnosis.
• • FNA biopsy is a routine part of the bronchoscopic examination of submucosal lesions.
• • Frozen section examination of FNA biopsy specimens may be misleading because of the tumors' similarity to small cell carcinoma.
• • Permanent hematoxylin and eosin preparations usually lead to the correct diagnosis, although confusion regarding atypical carcinoid still may lead to an inaccurate diagnosis.
• Bronchoscopy
• • Eighty percent of bronchial adenomas are visible under bronchoscopy, which usually is successful in localizing within and proximal to segmental orifices.
  • Accurate identification requires bronchial biopsy; biopsy should be performed.
  • Bleeding can occur, but reports of massive hemorrhage associated with biopsy are exaggerated. Most episodes of postbronchoscopy hemorrhage have followed attempts at partial or complete removal rather than simple biopsy. The submucosal location necessitates a biopsy deeper than usual. Dilute epinephrine is a helpful adjunct to prevent bleeding. General anesthesia and rigid bronchoscopy may be required for airway control if persistent hemorrhage occurs following fiberoptic bronchoscopy.
  • Bronchoscopy should be performed in all candidates for a bronchoplastic procedure in order to precisely define the limits of the planned bronchial resection.
  • If the endoscopist is not prepared to deal with airway bleeding, biopsy should be deferred until the patient has been sent to an appropriate facility.
• Thoracentesis
• • This can aid in diagnosis via cytological studies that confirm other diagnoses in the differential.
  • Thoracentesis can also be therapeutic when large pleural effusions cause respiratory insufficiency
  • Ultrasound guidance may be helpful when dealing with small effusions. 
• Mediastinoscopy
• • It is of little value in preoperative nodal staging in typical carcinoid tumors, unless mediastinal involvement is suspected.
  • It should be reserved for atypical carcinoid or for when evidence of mediastinal involvement is seen with CT scanning.
  • Even with mediastinal node involvement, resection of the carcinoid with mediastinal lymph node dissection provides excellent local control and 5-year survival.

Histologic Findings

Carcinoids originate from bronchial epithelial stem cells and are not of neural crest origin. Grossly, they appear as soft, highly vascularized, and pink-to-purplish tumors. They are usually covered by intact epithelium, which occasionally has squamous metaplasia, and ulceration can be present. Carcinoids usually are sessile, but they can be polypoid. They may penetrate the bronchial wall and occasionally may show parenchymal or peribronchial nodal extension.
 
Microscopically, the cells are uniform and round-to-polygonal; however, when they are located peripherally, a spindle shape predominates. The cellular arrangement usually involves small clusters, interlacing cords, or both, separated by well-vascularized connective tissue. Nuclei are small and oval, and finely granular chromatin with abundant eosinophilic cytoplasm is observed. Typical carcinoids, or Kulchitsky cell type I neuroendocrine tumors, have less than 2 mitoses per 2 mm² and they lack necrosis.
 
Atypical carcinoids, or Kulchitsky cell type II neuroendocrine tumors, have carcinoid morphology with 2-10 mitoses per 2 mm² or necrosis. They exhibit malignant histologic features and aggressive behavior. They exhibit pleomorphism, more mitotic activity, nuclear abnormalities, prominent nucleoli with peripheral palisading, and necrosis.
 
Kulchitsky type III cells are thought to be the cells of origin of small cell carcinoma.
 
A rare, pigmented, melanocytic variety of carcinoid has been described and is differentiated from melanoma.
 
An oncocytic type is a rare subtype of typical lesions with mixed cellular content, including typical carcinoid cells and large eosinophilic oncocytes. True oncocytic differentiation occurs.
 
Adenoid cystic carcinomas are slow-growing tumors with the propensity for submucosal invasion, perineural invasion, and distant metastasis. Numerous prominent mitochondria and serous secretory granules can be observed with electron microscopy.
 
Tumorlets are foci of atypical hyperplastic bronchial epithelium. These lesions are more commonly seen in middle-aged or older individuals with chronic pulmonary pathology. They are usually an incidental finding in a resected specimen or are found during an autopsy.

Staging

No correlation is shown to standard tumor, node, metastases (TNM) classifications. Most typical lesions are stage 1 tumors at presentation. More than 50% of atypical lesions are at stage 2 or 3 at presentation, with bronchopulmonary or mediastinal nodal involvement noted. Intraoperative biopsies of hilar and lobar nodal tissue and tissue in the involved bronchopulmonary segment, with frozen section analysis, are required.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Medical Care

In the absence of distant metastases, the treatment  of choice is complete removal of the primary carcinoid with maximal parenchymal preservation. This is based on the knowledge that most bronchial adenomas are only locally invasive. See Surgical Care below.

Adenoid cystic tumors are radiosensitive and postoperative radiotherapy is of value.

Surgical Care

Endoscopic resection

Bronchoscopic resection

This procedure is plagued by incomplete tumor removal, with frequent recurrence due to extraluminal tumor bulk, often with limited tumor visibility and accessibility via the bronchoscope. It also carries a high risk of hemorrhage.

Bronchoscopic resection is warranted to alleviate bronchial obstruction in patients in whom thoracotomy is prohibitive. Additionally, occasional preoperative use of this technique may allow assessment of the reversibility of distal parenchymal damage. Finally, the technique of argon-beam electrocoagulation may be very useful for bronchoscopic control of bleeding prior to definitive resection.

Neodymium:Yttrium-aluminum-garnet laser

The Nd:YAG laser reduces the risk of hemorrhage-related complications by means of photocoagulation. It is not recommended as a primary mode of tumor removal. Rarely, the Nd:YAG laser is applicable to a polypoid, easily accessible lesion on a narrow, uninvolved stalk.

Surgical resection

Surgical procedures

Preoperative risk assessment

• Chronic obstructive pulmonary disease
• Chronic renal failure 
• Cor pulmonale 
• Diabetes mellitus 
• Myocardial infarction within 6 months or unstable ischemic disease 
• Severe cardiac valvular disease 
• Congestive heart failure 
• Bleeding disorders 
• Peripheral vascular disease

• Exercise tolerance - May include informal evaluation using the patient’s history, a stair testing test, or a formal walk test
• Arterial blood gas testing 
• Pulmonary function tests - Spirometry, diffusion capacity, and split-function testing
•  Pulmonary reserve criteria
• • Forced expiratory volume in 1 second (FEV₁): Mortality risk is inversely proportional to FEV₁. With low FEV₁, expect prolonged postoperative mechanical ventilation.
  • Forced vital capacity: This value should be greater than 2 liters or at least 3 times the tidal volume. Mortality risk is inversely proportional to forced vital capacity.
  • Ratio of residual volume to total lung capacity: A value of greater than 50% suggests severe chronic obstructive pulmonary disease with airway closing volumes approaching total lung capacity. A contraindication includes a ratio of residual volume to total lung capacity of greater than 50%. 
  • Maximum breathing capacity: This should be more than 50% of predicted.
  • PaCO₂: A contraindication is a PaCO₂ of greater than 40.

Cardiac evaluation

• Electrocardiogram
• Stress testing 
• Echocardiography

Perioperative  management

FOLLOW-UP

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Further Outpatient Care

Chemotherapy and radiotherapy can be instituted if indicated, as discussed in Medical Care.

Transfer

If the endoscopist is not prepared to deal with airway bleeding, biopsy should be deferred until the patient has been sent to an appropriate facility.

Deterrence/Prevention

No preventive regimen has been established. Smoking cessation is always a good thing but has no specific effect on these tumors.

Complications

• Delayed hemorrhage
• Bronchial anastomotic leak
• Coagulopathy
• Myocardial ischemia
• Need for persistent mechanical ventilation
• Mucoepidermoid carcinoma - Known to result in intracranial metastases, even in cases of minimal bronchial wall involvement
• Carcinoid - Solid organ metastases (eg, to the liver) possible

Prognosis

The overall 5-year patient survival rates for bronchial adenomas are excellent at approximately 96%. Scattered reports describe local recurrences or distant metastases following adequate resection of typical lesions.

Carcinoids 

The slow growth pattern of carcinoids often prolongs the natural history of the disease process. A 5-year patient survival rate of 92% and 10-year survival rate of 88% has been reported for typical carcinoids treated with complete resection and formal mediastinal dissection. These excellent results applied to patients with both N1 and N2 disease, although those with N2 status received adjunctive radiation therapy. In atypical carcinoids, the survival rate is decreased to 60% at 5 years and 49% at 10 years.

Adenoid cystic carcinoma

After resection, the 5-year survival rate is approximately 83% and the disease-free survival rate is 60%. Patients with adenoid cystic carcinoma have an excellent prognosis because the tumor grows slowly and is radiosensitive. The best results are achieved when complete resection is accomplished; however, prolonged patient survival is possible even with incomplete resection.

Mucoepidermoid carcinoma 

The 5-year survival rate is 11.1%. This tumor is known to cause intracranial metastases, even in the presence of minimal bronchial wall involvement. Chemotherapy and radiation are used mainly for palliation.

Patient Education

For excellent patient education resources, visit eMedicine's Procedures Center. In addition, see eMedicine's patient education article Bronchoscopy.

MISCELLANEOUS

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Medical/Legal Pitfalls

Failure to diagnose 

The most common medicolegal hazard is failure to diagnose. Patients with bronchial adenoma may present with hemoptysis, chronic cough, recurring pneumonia, or simple chest discomfort. While radiographs may show segmental or lobar atelectasis or infiltrate, the tumor itself is rarely large enough to be visible and radiographic findings may be completely normal.

CT scanning should always be performed if the radiograph continues to show atelectasis over a period of 2-3 months.

Definitive diagnosis is made with bronchoscopy. Hemoptysis almost always prompts bronchoscopy, but the general clinician should remember that chronic cough and recurring pneumonia are also indications. No physician should be sued successfully if an honest effort is made to diagnose persisting atelectasis or recurring pneumonia, but that effort should generally include CT scanning and bronchoscopy.

Bleeding 

Bronchoscopic biopsy may lead to bleeding, which can be severe and life threatening. Occasional reports describe spontaneous severe bleeding, or the tumor can bleed following biopsy. Any bleeding in the airway can be life threatening; however, this bleeding can usually be controlled using conservative measures. The availability of argon-beam electrocoagulation in the bronchoscopic suite can be beneficial.

Bleeding following bronchoscopy is the most dangerous pitfall. If the endoscopist is not prepared to deal with airway bleeding, a biopsy should be deferred until the patient has been sent to an appropriate facility.
 
Some surgeons believe the bronchoscopy should always be performed through a straight bronchoscope, but, with current equipment, fiberoptic bronchoscopy is safe. A straight bronchoscope permits better control of a bleeding biopsy site than a flexible bronchoscope, but the fiberoptic bronchoscope allows more complete inspection of all orifices and all segmental branches.

To successfully deal with bleeding, endotracheal intubation should be available and the operator should have the ability to intubate and to use an endotracheal tube to tamponade the bleeding tumor, or at least to block off the bronchus on the bleeding side to permit ventilation through the nonbleeding side. Rigid bronchoscopy should be available within the facility.

Failure to perform a biopsy 

Because of the risk of bleeding, many clinicians have fallen into an associated pitfall, which is a failure to perform a biopsy on anything in the tracheobronchial tree that looks as if it may be a bronchial adenoma. To avoid this, perform the biopsy but be prepared to handle any hemorrhage.

Special Concerns

• Future and controversies - Tumorlet etiology
• • Hyperplastic proliferation of neuroendocrine cells, rather than neoplasms, as proposed by Cutz¹
  • True neoplasm, because D'Agati et al² have reported peribronchial nodal metastases
  • Diffuse form as possible etiology of small airway obliterative disease as proposed by Aguayo et al³

ACKNOWLEDGMENTS

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Acknowledgments
• References

We would like to acknowledge the contributions of Dr. Ellis Salloum, MD, who was a coauthor on the original version of this article.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Acknowledgments
• References

1. Cutz E. Neuroendocrine cells of the lung. An overview of morphologic characteristics and development. Exp Lung Res. Nov 1982;3(3-4):185-208. [Medline].
2. D'Agati VD, Perzin KH. Carcinoid tumorlets of the lung with metastasis to a peribronchial lymph node. Report of a case and review of the literature. Cancer. May 15 1985;55(10):2472-6. [Medline].
3. Aguayo SM, Miller YE, Waldron JA Jr, Bogin RM, Sunday ME, Staton GW Jr, et al. Brief report: idiopathic diffuse hyperplasia of pulmonary neuroendocrine cells and airways disease. N Engl J Med. Oct 29 1992;327(18):1285-8. [Medline].
4. Dagostino RS, Ponn RB. Adenoid Cystic Carcinoma and Other Primary Salivery Gland-Type Tumors of the Lung. In: Shields TW, LoCicero J 3rd, Ponn RB, Rusch VW, eds. General Thoracic Surgery. 6^th ed. Philadelphia, Pa: Lippincott, Williams & Wilkins; 2005:1768-77.
5. Darling G, Ginsberg RJ. Carcinoid Tumors. In: Shields TW, LoCicero J 3rd, Ponn RB, Rusch VW, eds. General Thoracic Surgery. 6^th ed. Philadelphia, Pa: Lippincott, Williams & Wilkins; 2005:1753-67.
6. Faber LP. Sleeve Lobectomy. In: Shields TW, LoCicero J 3rd, Ponn RB, Rusch VW, eds. General Thoracic Surgery. 6^th ed. Philadelphia, Pa: Lippincott, Williams & Wilkins; 2005:458-69.
7. Fink G, Krelbaum T, Yellin A, Bendayan D, Saute M, Glazer M, et al. Pulmonary carcinoid: presentation, diagnosis, and outcome in 142 cases in Israel and review of 640 cases from the literature. Chest. Jun 2001;119(6):1647-51. [Medline].
8. Goldberg M, Patchefsky AS. Uncommon Tumors of the Tracheobronchial Tree: Diagnosis and Management. Chest Surg Clin North Amer. 2003;13:1-174.
9. Kirshbom PM, Harpole DH Jr. Bronchial Gland Tumors. In: Pearson FG, Cooper JD, Deslauriers J, Ginsberg RJ, Hiebert CA, Patterson GA, Urschel HC, eds. Thoracic Surgery. 2^nd ed. New York, NY: Churchill Livingstone; 2002:763-71.
10. Litzky L. Epithelial and soft tissue tumors of the tracheobronchial tree. Chest Surg Clin N Am. Feb 2003;13(1):1-40. [Medline].
11. Parsons RB, Milestone BN, Adler LP. Radiographic assessment of airway tumors. Chest Surg Clin N Am. Feb 2003;13(1):63-77, v-vi. [Medline].
12. Scott WJ. Surgical treatment of other bronchial tumors. Chest Surg Clin N Am. Feb 2003;13(1):111-28. [Medline].
13. Warren WH, Faber LP. Bronchoscopic Evaluation of the Lungs and Tracheobronchial Tree. In: Shields TW, LoCicero J 3rd, Ponn RB, Rusch VW, eds. General Thoracic Surgery. 6^th ed. Philadelphia, Pa: Lippincott, Williams & Wilkins; 2005:284-98.
14. Watanabe Y. Tracheal Sleeve Pneumonectomy. In: Shields TW, LoCicero J 3rd, Ponn RB, Rusch VW, eds. General Thoracic Surgery. 6^th ed. Philadelphia, Pa: Lippincott, Williams & Wilkins; 2005:486-95.
15. Whyte RI, Ferguson MK. Preoperative Preparation of Patients for Thoracic Surgery. Thor Surg Clin. 2005;15:185-322.

Article Last Updated: Aug 13, 2007