Sections

Pilomatrixoma

Overview

Background

A pilomatrixoma, also known as calcifying epithelioma of Malherbe, is a benign appendageal tumor with differentiation toward hair follicle matrix cells. It usually manifests as a solitary, asymptomatic, firm nodule. It has long been considered a rare tumor, but it may be more common than previously realized. It is more common in children, but occurrence in adults is increasingly being recognized.^{[1, 2, 3, 4, 5]}Recommended treatment is surgical excision. Multiple pilomatrixomas have been observed, mainly in association with myotonic dystrophy, but also with other syndromes including Rubenstein-Taybi syndrome and constitutional mismatch repair deficiency (CMMRD) syndrome.^{[6, 7, 8]}Pilomatrix carcinoma is a rare condition.^{[9, 10, 11, 12, 13, 14, 15, 16]}

Pathophysiology

In one study of 10 pilomatrixoma lesions, all immunostaining results were strongly positive for BCL2.^[17]This is a proto-oncogene that helps suppress apoptosis in benign and malignant tumors; these data suggest that faulty suppression of apoptosis contributes to the pathogenesis of these tumors.

More recently, investigators have demonstrated that the proliferating cells of human pilomatrixomas show prominent staining with antibodies directed against LEF-1 (a marker for hair matrix cells). Evidence also indicates that S100 proteins can be used as biochemical markers in characterization of pilomatrixomas.^[18]These data provide biochemical support of morphological evidence that these tumors are derived from hair matrix cells. Furthermore, investigators have shown that at least 75% of persons with pilomatrixomas who have examined have mutations in the gene CTNNB1; these data directly implicate beta-catenin/LEF misregulation as the major cause of hair matrix cell tumorigenesis in humans.^{[19, 20, 21]}

Etiology

Investigators in one study showed that at least 75% of the lesions studied had mutations in the gene CTNNB1; these data directly implicate beta-catenin/LEF misregulation as the major cause of hair matrix cell tumorigenesis in humans.

Frequency

United States

Pilomatrixomas have long been considered uncommon cutaneous tumors; however, they may be more common than is realized, especially in children and young adults. In one American dermatopathology laboratory, pilomatrical neoplasms were considered the most common solid cutaneous tumors in patients aged 20 years or younger.^[22]

International

In one dermatopathology laboratory in the United Kingdom, pilomatrixomas accounted for 1 in 500 histologic specimens. Investigators found 37 cases published in Japanese dental journals between 1977 and 1994.^[23]In Turkey, 15 patients were seen in a pediatric surgery clinic from 1984-1994.^[2]In France, a retrospective study of records in one surgery clinic revealed 33 patients who had undergone surgery for pilomatrixomas between 1989 and 1997.^[24]

Race

Most reported cases have occurred in white persons. Whether this represents publication bias or a true racial predisposition is unclear.

Sex

Most studies report a slight predominance in females.^[25]In a comprehensive review of 150 papers, the female-to-male ratio was 1.15:1.^[25]

Age

Most reported cases have occurred in children. Lesions are often discovered in the first 2 years of life; however, in a retrospective study of 209 cases published in 1998, investigators found the age of presentation showed a bimodal pattern, with the first peak being 5-15 years and the second being 50-65 years.^[26]In a comprehensive review of 150 pilomatrixoma articles, the mean age at excision was 16 years and 7 months, with a range from 5 months to 97 years.^[25]

Prognosis

Pilomatrixomas are not associated with mortality. Very large tumors (≤ 18 cm) can cause considerable discomfort but are uncommon. Pilomatrix carcinomas are also uncommon, but they are locally invasive and can cause visceral metastases and death.

Clinical Presentation

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Demircan M, Balik E. Pilomatricoma in children: a prospective study. Pediatr Dermatol. 1997 Nov-Dec. 14(6):430-2. [QxMD MEDLINE Link].
Kaddu S, Soyer HP, Cerroni L, Salmhofer W, Hodl S. Clinical and histopathologic spectrum of pilomatricomas in adults. Int J Dermatol. 1994 Oct. 33(10):705-8. [QxMD MEDLINE Link].
Marrogi AJ, Wick MR, Dehner LP. Pilomatrical neoplasms in children and young adults. Am J Dermatopathol. 1992 Apr. 14(2):87-94. [QxMD MEDLINE Link].
Wells NJ, Blair GK, Magee JF, Whiteman DM. Pilomatrixoma: a common, benign childhood skin tumour. Can J Surg. 1994 Dec. 37(6):483-6. [QxMD MEDLINE Link].
Aslan G, Erdogan B, Akoz T, Gorgu M, Seckin S, Terzioglu A. Multiple occurrence of pilomatrixoma. Plast Reconstr Surg. 1996 Sep. 98(3):510-3. [QxMD MEDLINE Link].
Black SJ, Marple BF, Vuitch F. Multiple giant pilomatrix carcinomas of the head and neck. Otolaryngol Head Neck Surg. 1993 Sep. 109(3 Pt 1):543-7. [QxMD MEDLINE Link].
Geh JL, Moss AL. Multiple pilomatrixomata and myotonic dystrophy: a familial association. Br J Plast Surg. 1999 Mar. 52(2):143-5. [QxMD MEDLINE Link].
Martelli G, Giardini R. Pilomatrix carcinoma: a case report and review of the literature. Eur J Surg Oncol. 1994 Dec. 20(6):703-4. [QxMD MEDLINE Link].
McCulloch TA, Singh S, Cotton DW. Pilomatrix carcinoma and multiple pilomatrixomas. Br J Dermatol. 1996 Feb. 134(2):368-71. [QxMD MEDLINE Link].
Sable D, Snow SN. Pilomatrix carcinoma of the back treated by mohs micrographic surgery. Dermatol Surg. 2004 Aug. 30(8):1174-6. [QxMD MEDLINE Link].
Sassmannshausen J, Chaffins M. Pilomatrix carcinoma: a report of a case arising from a previously excised pilomatrixoma and a review of the literature. J Am Acad Dermatol. 2001 Feb. 44(2 Suppl):358-61. [QxMD MEDLINE Link].
Mitteldorf CATDS, Vilela RS, Fugimori ML, de Godoy CD, Coudry RA. Novel Mutations in Pilomatrixoma, CTNNB1 p.s45F, and FGFR2 p.s252L: A Report of Three Cases Diagnosed by Fine-Needle Aspiration Biopsy, with Review of the Literature. Case Rep Genet. 2020. 2020:8831006. [QxMD MEDLINE Link].
Gupta A, George R, Aboobacker FN, ThamaraiSelvi B, Priscilla AJ. Pilomatricomas and café au lait macules as herald signs of constitutional mismatch repair deficiency (CMMRD) syndrome-A case report. Pediatr Dermatol. 2020 Sep 2. [QxMD MEDLINE Link].
Li Q, Zhang G. Minimally Invasive Curettage: A Better Method of Removing Childhood Pilomatricomas than Surgical Excision. J Am Acad Dermatol. 2020 Aug 20. [QxMD MEDLINE Link].
Bueno ALA, de Souza MEV, Graziadio C, Kiszewski AE. Multiple pilomatricomas in twins with Rubinstein-Taybi syndrome. An Bras Dermatol. 2020 Sep - Oct. 95 (5):619-622. [QxMD MEDLINE Link].
Farrier S, Morgan M. bcl-2 expression in pilomatricoma. Am J Dermatopathol. 1997 Jun. 19(3):254-7. [QxMD MEDLINE Link].
Kizawa K, Toyoda M, Ito M, Morohashi M. Aberrantly differentiated cells in benign pilomatrixoma reflect the normal hair follicle: immunohistochemical analysis of Ca-binding S100A2, S100A3 and S100A6 proteins. Br J Dermatol. 2005 Feb. 152(2):314-20. [QxMD MEDLINE Link].
Chan EF, Gat U, McNiff JM, Fuchs E. A common human skin tumour is caused by activating mutations in beta-catenin. Nat Genet. 1999 Apr. 21(4):410-3. [QxMD MEDLINE Link].
Kajino Y, Yamaguchi A, Hashimoto N, Matsuura A, Sato N, Kikuchi K. beta-Catenin gene mutation in human hair follicle-related tumors. Pathol Int. 2001 Jul. 51(7):543-8. [QxMD MEDLINE Link].
Lazar AJ, Calonje E, Grayson W, et al. Pilomatrix carcinomas contain mutations in CTNNB1, the gene encoding beta-catenin. J Cutan Pathol. 2005 Feb. 32(2):148-57. [QxMD MEDLINE Link].
Schwarz Y, Pitaro J, Waissbluth S, Daniel SJ. Review of pediatric head and neck pilomatrixoma. Int J Pediatr Otorhinolaryngol. 2016 Jun. 85:148-53. [QxMD MEDLINE Link].
Yoshimura Y, Obara S, Mikami T, Matsuda S. Calcifying epithelioma (pilomatrixoma) of the head and neck: analysis of 37 cases. Br J Oral Maxillofac Surg. 1997 Dec. 35(6):429-32. [QxMD MEDLINE Link].
Duflo S, Nicollas R, Roman S, Magalon G, Triglia JM. Pilomatrixoma of the head and neck in children: a study of 38 cases and a review of the literature. Arch Otolaryngol Head Neck Surg. 1998 Nov. 124(11):1239-42. [QxMD MEDLINE Link].
Jones CD, Ho W, Robertson BF, Gunn E, Morley S. Pilomatrixoma: A Comprehensive Review of the Literature. Am J Dermatopathol. 2018 Sep. 40 (9):631-641. [QxMD MEDLINE Link].
Julian CG, Bowers PW. A clinical review of 209 pilomatricomas. J Am Acad Dermatol. 1998 Aug. 39(2 Pt 1):191-5. [QxMD MEDLINE Link].
Rotenberg M, Laccourreye O, Cauchois R, Laccourreye L, Putterman M, Brasnu D. Head and neck pilomatrixoma. Am J Otolaryngol. 1996 Mar-Apr. 17(2):133-5. [QxMD MEDLINE Link].
Shields JA, Shields CL, Eagle RC Jr, Mulvey L. Pilomatrixoma of the eyelid. J Pediatr Ophthalmol Strabismus. 1995 Jul-Aug. 32(4):260-1. [QxMD MEDLINE Link].
Strobl H, Emshoff R. Pilomatrixoma of the cheek: report of case. J Oral Maxillofac Surg. 1995 Nov. 53(11):1355-7. [QxMD MEDLINE Link].
Hada M, Meel R, Kashyap S, Jose C. Eyelid pilomatrixoma masquerading as chalazion. Can J Ophthalmol. 2017 Apr. 52 (2):e62-e64. [QxMD MEDLINE Link].
Schweitzer WJ, Goldin HM, Bronson DM, Brody PE. Solitary hard nodule on the forearm. Pilomatricoma. Arch Dermatol. 1989 Jun. 125(6):828-9, 832. [QxMD MEDLINE Link].
Alfsen GC, Strom EH. Pilomatrixoma of the ovary: a rare variant of mature teratoma. Histopathology. 1998 Feb. 32(2):182-3. [QxMD MEDLINE Link].
Sevin K, Can Z, Yilmaz S, Saray A, Yormuk E. Pilomatrixoma of the earlobe. Dermatol Surg. 1995 Mar. 21(3):245-6. [QxMD MEDLINE Link].
Kwon D, Grekov K, Krishnan M, Dyleski R. Characteristics of pilomatrixoma in children: a review of 137 patients. Int J Pediatr Otorhinolaryngol. 2014 Aug. 78 (8):1337-41. [QxMD MEDLINE Link].
Bayle P, Bazex J, Lamant L, Lauque D, Durieu C, Albes B. Multiple perforating and non perforating pilomatricomas in a patient with Churg-Strauss syndrome and Rubinstein-Taybi syndrome. J Eur Acad Dermatol Venereol. 2004 Sep. 18(5):607-10. [QxMD MEDLINE Link].
de la Torre JP, Saiz A, Garcia-Arpa M, Rodriguez-Peralto JL. Pilomatricomal horn: a new superficial variant of pilomatricoma. Am J Dermatopathol. 2006 Oct. 28(5):426-8. [QxMD MEDLINE Link].
del Pozo J, Martinez W, Yebra-Pimentel MT, Fonseca E. Lymphangiectatic variant of pilomatricoma. J Eur Acad Dermatol Venereol. 2004 Sep. 18(5):575-6. [QxMD MEDLINE Link].
Fender AB, Reale VF, Scott GA. Anetodermic pilomatricoma with perforation. J Am Acad Dermatol. 2008 Mar. 58(3):535-6. [QxMD MEDLINE Link].
Ali MZ, Ali FZ. Pilomatrixoma breast mimicking carcinoma. J Coll Physicians Surg Pak. 2005 Apr. 15(4):248-9. [QxMD MEDLINE Link].
Reynaud P, Orliaguet T, Robin YM, et al. [Mammary pilomatrixoma clinically mimicking carcinoma]. Ann Pathol. 1997 Jul. 17(3):213-4. [QxMD MEDLINE Link].
Cambiaghi S, Ermacora E, Brusasco A, Canzi L, Caputo R. Multiple pilomatricomas in Rubinstein-Taybi syndrome: a case report. Pediatr Dermatol. 1994 Mar. 11(1):21-5. [QxMD MEDLINE Link].
Masuno M, Imaizumi K, Ishii T, Kuroki Y, Baba N, Tanaka Y. Pilomatrixomas in Rubinstein-Taybi syndrome. Am J Med Genet. 1998 Apr 28. 77(1):81-2. [QxMD MEDLINE Link].
Noguchi H, Kayashima K, Nishiyama S, Ono T. Two cases of pilomatrixoma in Turner's syndrome. Dermatology. 1999. 199(4):338-40. [QxMD MEDLINE Link].
Cooper PH, Fechner RE. Pilomatricoma-like changes in the epidermal cysts of Gardner's syndrome. J Am Acad Dermatol. 1983 May. 8(5):639-44. [QxMD MEDLINE Link].
Pujol RM, Casanova JM, Egido R, Pujol J, de Moragas JM. Multiple familial pilomatricomas: a cutaneous marker for Gardner syndrome?. Pediatr Dermatol. 1995 Dec. 12(4):331-5. [QxMD MEDLINE Link].
Richet C, Maza A, Dreyfus I, Bourrat E, Mazereeuw-Hautier J. Childhood pilomatricomas: Associated anomalies. Pediatr Dermatol. 2018 Jul 1. [QxMD MEDLINE Link].
Hughes J, Lam A, Rogers M. Use of ultrasonography in the diagnosis of childhood pilomatrixoma. Pediatr Dermatol. 1999 Sep-Oct. 16(5):341-4. [QxMD MEDLINE Link].
Ichikawa T, Nakajima Y, Fujimoto H, et al. Giant calcifying epithelioma of Malherbe (pilomatrixoma): imaging features. Skeletal Radiol. 1997 Oct. 26(10):602-5. [QxMD MEDLINE Link].
Domanski HA, Domanski AM. Cytology of pilomatrixoma (calcifying epithelioma of Malherbe) in fine needle aspirates. Acta Cytol. 1997 May-Jun. 41(3):771-7. [QxMD MEDLINE Link].
Kumar N, Verma K. Fine needle aspiration (FNA) cytology of pilomatrixoma. Cytopathology. 1996 Apr. 7(2):125-31. [QxMD MEDLINE Link].
Ortiz J, Garcia Macias C, Abad M, Flores T, Paz JI, Bullon A. Pilomatrixoma: a description of two cases diagnosed by fine-needle aspiration. Diagn Cytopathol. 1995 Mar. 12(2):155-7. [QxMD MEDLINE Link].
Thinakaran V, Singh SK, Simples P, Nadimpalli V. Fine needle aspiration diagnosis of pilomatrixoma. A case report. Acta Cytol. 1998 May-Jun. 42(3):769-71. [QxMD MEDLINE Link].
Wong MP, Yuen ST, Collins RJ. Fine-needle aspiration biopsy of pilomatrixoma: still a diagnostic trap for the unwary. Diagn Cytopathol. 1994. 10(4):365-9; discussion 369-70. [QxMD MEDLINE Link].
Han K, Ha HJ, Kong JS, Myung JK, Park S, Kim JS, et al. Importance of Individual Ghost Cells in Fine-Needle Aspiration Cytology Diagnosis of Pilomatricoma. J Pathol Transl Med. 2018 Jan. 52 (1):45-50. [QxMD MEDLINE Link].
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Morales A, McGoey J. Pilomatricoma: treatment by incision and curettement. J Am Acad Dermatol. 1980 Jan. 2(1):44-6. [QxMD MEDLINE Link].
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Media Gallery

Pilomatricoma with prominent basaloid cells.
Ghost cells (shadow cells) and basaloid cells, associated with a granulomatous reaction. Shadow cells are also seen in this high-power micrograph.

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Author

Jaggi Rao, MD, FRCPC Clinical Professor of Medicine, Division of Dermatology and Cutaneous Sciences, Director of Dermatology Residency Program, University of Alberta Faculty of Medicine and Dentistry, Canada

Jaggi Rao, MD, FRCPC is a member of the following medical societies: American Academy of Dermatology, American Society for Dermatologic Surgery, American Society for Laser Medicine and Surgery, Canadian Dermatology Association, Canadian Medical Association, Canadian Medical Protective Association, Pacific Dermatologic Association, Royal College of Physicians and Surgeons of Canada

Disclosure: Nothing to disclose.

Coauthor(s)

Kaushik P Venkatesh, MBA MD Candidate, Harvard Medical School

Disclosure: Nothing to disclose.

Specialty Editor Board

Richard P Vinson, MD Assistant Clinical Professor, Department of Dermatology, Texas Tech University Health Sciences Center, Paul L Foster School of Medicine; Consulting Staff, Mountain View Dermatology, PA

Richard P Vinson, MD is a member of the following medical societies: American Academy of Dermatology, Texas Medical Association, Association of Military Dermatologists, Texas Dermatological Society

Disclosure: Nothing to disclose.

Warren R Heymann, MD Head, Division of Dermatology, Professor, Department of Internal Medicine, Rutgers New Jersey Medical School

Warren R Heymann, MD is a member of the following medical societies: American Academy of Dermatology, American Society of Dermatopathology, Society for Investigative Dermatology

Disclosure: Nothing to disclose.

Chief Editor

Dirk M Elston, MD Professor and Chairman, Department of Dermatology and Dermatologic Surgery, Medical University of South Carolina College of Medicine

Dirk M Elston, MD is a member of the following medical societies: American Academy of Dermatology

Disclosure: Nothing to disclose.

Additional Contributors

Andrew Lin, MD, FRCPC  Associate Professor, Department of Internal Medicine, Division of Dermatology, University of Alberta

Andrew Lin, MD, FRCPC is a member of the following medical societies: American Academy of Dermatology, Royal College of Physicians and Surgeons of Canada

Disclosure: Nothing to disclose.

Acknowledgements

Smeena Khan, MD Private Practice, Adult and Pediatric Dermatology Associates

Smeena Khan, MD is a member of the following medical societies: Alpha Omega Alpha and American Academy of Dermatology

Disclosure: Nothing to disclose.

Andrei I Metelitsa, MD Chief Resident, Division of Dermatology and Cutaneous Sciences, University of Alberta, Canada

Disclosure: Nothing to disclose.

Pilomatrixoma

Background

Pathophysiology

Etiology

Epidemiology

Frequency

Race

Sex

Age

Prognosis

References

Tables

Contributor Information and Disclosures

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