A 16-year-old female presents with multiple flesh-colored to yellow papules under the lower eyelids that range from 1 to 2 mm. One of these lesions is biopsied and is illustrated below. Immunohistochemistry reveals the basolateral cell layer of the tubules to stain positive for EMA and the inner ductal lining staining positive for CEA. Which of the following diagnoses is CORRECT?
C) Microcystic adnexal carcinoma
D) Desmoplastic basal cell carcinoma
These lesions are syringomas, which most commonly present as multiple clustered white-yellow papules predominantly on the lower eyelids of young women (Table 9-1A). There is debate as to whether they are hamartomas versus neoplasms since solitary lesions also commonly present in the head and neck region. Generalized and eruptive forms exist that most commonly present on the chest, neck, and forearms. Microscopically, the tumor is composed of superficial dermal cords and tubules with a “tadpole” or “comma-shaped” appearance. The tubules are composed of two rows of cells with the apical layer frequently containing vacuolated or even clear cytoplasm due to secondary glycogen accumulation. Clear cell syringoma with abundant accumulations of glycogen is associated with glucose intolerance and diabetes mellitus. An eosinophilic cuticle usually lines the inner ductules, identical to that of normal eccrine sweat ducts, and the lumens contain eosinophilic to amphophilic secretions. Syringomas are believed to be of eccrine derivation. Immunohistochemistry will reveal the basolateral cells to express p63 and EMA, and the inner cuticular lining is highlighted by CEA.
Reproduced with permission from Desman GT, Ozerdem U, Shin SJ: Neighboring look-a-likes: distinguishing between breast and dermatologic lesions, Adv Anat Pathol 2014 Jul;21(4):228-247
Syringoma. (A) There are numerous tubules, some of which contain tapered ends imparting a “tadpole” appearance. Note the eosinophilic secretion present within the lumen. (B) Clear cell syringoma composed of tubules and lobules containing two or more cell layers with abundant clear cytoplasm.
Table 9-1A. Syringoma
Plaque-like, milia-like, linear, and eruptive variants
Upper cheeks, below eyelids, genitalia, thighs
Small, discrete, whitish or yellowish papules, 1-4 mm in diameter
Superficial dermal well-defined tumor
Small tubule or epithelial aggregates, often comma shaped
Central lumina with luminal cuticle
Polygonal or flattened tumor cells with eosinophilic or clear cytoplasm
Absence of cytologic atypia, mitoses, and infiltrative growth