Apocrine Tubular Adenoma
Elsa F. Velazquez, MD
David Cassarino, MD, PhD
Key Facts
Clinical Issues
Scalp
Nodule measuring < 2 cm
Microscopic Pathology
Intradermal tumor
Sometimes arises in association with nevus sebaceous and syringocystadenoma papilliferum
Tubules of different size and shape
Some cystically dilated
Papillary projections devoid of fibrovascular cores
Outer layer composed of myoepithelial cells
Inner layer composed of apocrine cells
Top Differential Diagnoses
Syringocystadenoma papilliferum
Papillary eccrine adenoma
Apocrine hamartoma
Apocrine carcinoma
 Apocrine tubular adenoma is usually a well-circumscribed intradermal nodule composed of variably sized and shaped tubules. Some tubular structures are cystically dilated. |
 The tubules are lined by at least 2 layers of cells. The outer layer is composed of small myoepithelial cells  , and the luminal layer is composed of columnar apocrine cells  with apical snouts. |
TERMINOLOGY
Synonyms
Apocrine adenoma, tubulopapillary hidradenoma, papillary tubular adenoma
Definitions
Rare benign adnexal neoplasm with apocrine differentiation
CLINICAL ISSUES
Epidemiology
Incidence
Rare tumor
Age
Wide age distribution (range: 18-78 years)
Gender
Female predominance (2:1)
Presentation
Scalp nodule
Other locations include face, axilla, anogenital area, extremities
< 2 cm in diameter
