[Anatomoclinical and immunohistochemical study of hidradenoma papilliferum, a tumor deriving from anogenital mammary-like glands].

AIM: To specify the clinical, histopathological and immunochemical features in a large series of hidradenoma papilliferum patients and to point out similarities with breast disease.

PATIENTS AND

METHODS

We performed a monocentric retrospective histopathological study. Cases of hidradenoma papilliferum seen at the dermatopathology laboratory of Strasbourg (1977-2017) were included and analyzed with hematoxylin-eosin staining and immunostaining. Diagnosis was confirmed where tubular formations and papillary proliferations were noted and were lined by a luminal layer of columnar cells surrounded by a basal layer of myoepithelial cells.

RESULTS

We included 32 cases solely involving women of a mean age of 49 years. Most cases involved the vulva (67 %) or the perianal region (25 %). The lesions ranged in size from 3 to 25mm. They occurred as solitary, non-ulcerated, skin-colored and cyst-like lesions. They were mostly localized in the mid-dermis. We identified several peculiar morphological variants. Three HP had a structure resembling tubular apocrine papillary adenoma, 3 were similar to apocrine cystadenoma, while 9 HP, of which 3 involved epidermal hyperplasia, were connected with the overlying epidermis and had dense stromal infiltrate in plasma cells, closely resembling syringocystadenoma papilliferum. Sixteen tumors had no features of note. Similarities with breast tumors were revealed through columnar cell hyperplasia (6 cases), high mitotic rates (4 cases), and atypical nuclei (3 cases). Anogenital mammary-like glands were found in the immediate vicinity of 10 HP. Myoepithelial cells were immunoreactive for smooth muscle actin and p63, while luminal cells were immunoreactive for CK7, CK8, EMA, and, in a more focused and less consistent manner, for Ber-EP4, CD117, PHLDA1 and androgen receptors.

CONCLUSION

Our study highlighted a variety of patterns and cell morphologies, on occasion within a single tumor, identical to breast disease. Histological and immunochemical examination revealed that anogenital mammary-like glands and HP share common features, which militates in favor of a common histogenesis.