UNASSIGNED: Oncocytes are epithelial cells characterized by their abundant eosinophilic and finely granular cytoplasm.   Their histologic appearance is due to excessive amounts of cytoplasmic mitochondria. Oncocytes generally occur in the setting of @entity5 . @entity1637 , or @entity5 composed primarily of oncocytes, are typically found in the kidneys. Other common sites include the salivary, thyroid, and parathyroid glands. @entity42779 has only been rarely reported in various cutaneous @entity5 .   We report a case of an elderly male presenting with a 5 millimeter erythematous papule on his left scalp, who underwent a shave biopsy showing a nodular, dermal-based @entity5 with prominent ductal differentiation, composed of multiple small, well-formed lumina surrounded by enlarged, bland-appearing epithelioid cells. @entity5822 , EMA, and mCEA immunohistochemical stains were positive, consistent with adnexal differentiation. PTAH and LFB stains highlighted the cytoplasmic granules, consistent with mitochondria.   The overall findings were consistent with oncocytic nodular @entity13152 . Oncocytic @entity13152 is a very rare entity, with only 1 previously reported case in the literature.

A Rare Case of XXXX .

@entity42779 :: ('MESH:C535584', 'Disease') :: ['Oncocytic metaplasia'] @entity1637 :: ('MESH:D018249', 'Disease') :: ['Oncocytomas'] @entity5 :: ('MESH:D009369', 'Disease') :: ['adnexal tumor', 'benign neoplasms', 'neoplasms', 'tumors'] @entity13152 :: ('MESH:D018250', 'Disease') :: ['hidradenoma'] @entity5822 :: ('3855', 'Gene') :: ['CK7']
@entity13152 :: (MESH:D018250,Disease) :: ['Cutaneous Oncocytic Hidradenoma']
