Excerpt from Eccrine Spiradenoma

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Background

Eccrine spiradenoma (ES) usually manifests as a solitary, 1 cm in diameter, gray, pink, purple, red, or blue nodule on the upper half of the ventral side of the body. ES can be painful, often in paroxysms. Multiple ESs have been reported. Their initial elaboration is attributed to Kersting and Helwig.¹

ES is usually benign. It can occur in infancy but most commonly arises in persons aged 15-35 years. About 15 cases of linear/zosteriform/nevoid/blaschkoid multiple spiradenomas exist in the literature.^{2, 3} About 50 case reports of malignant ES (MES) exist in the literature. Dabska⁴ first described MES in 1972.

ES can occur in Brooke-Spiegler syndrome, which manifests with cylindromas, ES, and trichoepitheliomas. In this syndrome, lesions can have combined features of both cylindromas and ES.^{5, 6}

Pathophysiology

A defective tumor suppressor gene is believed to result in the development of ES. In Brooke-Spiegler syndrome, of which ESs are a manifestation, the defective gene is the CYLD gene on chromosome 9. Work remains to be performed on the genetic defect causing isolated and sporadic ESs.

The expression of p53 in MES seems to be increased.

The cells of origin of ES appear to have apocrine and trichoepitheliomatous differentiation, ie, they have complex hair follicle (folliculosebaceous apocrine) differentiation rather than eccrine differentiation.

In cases of linear/zosteriform/nevoid/blaschkoid multiple ESs, an abnormal clone arising during embryogenesis is postulated to produce the multiple abnormal cells that result in such ESs.

In a cytogenetic study, Dijkhuizen et al⁷ found an ES and 2 lymph node metastases, with a growth pattern and microscopic appearance typical for benign ES, a 46,XY-5,del(16)(q22),+mar(t(?;5)(?::5q13----5qter)) karyotype.

These similar genetic defects seem to support a relationship between the chromosomal abnormalities and the clinical malignant action of this benign-appearing neoplasm.

Frequency

ES is rare worldwide. MES is very rare worldwide.

Mortality/Morbidity

ES can be painful. The rate of malignant transformation is very low, and, sometimes, malignant transformation has been reported to develop spontaneously. The rate of metastasis is about 50% and can result in death.

Race

No racial link exists in ES.

Sex

No sexual predilection exists in ES or MES.

Age

• ES has been reported to arise in infancy but is rare.
• Most ESs arise in persons aged 15-35 years.
• MESs tend to develop after age 50 years. MES presents at an average age of 59 years (range, 21-92 y).

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