Syringocystadenocarcinoma Papilliferum in the Perianal Area

Abstract

Syringocystadenocarcinoma papilliferum (SCACP) is a very rare cutaneous adnexal neoplasm. SCACP presents histologic variability, and it is difficult to establish the diagnosis from a punch biopsy. SCACP has an overall configuration similar to that of syringocystadenoma papilliferum (SCAP). When we diagnose SCACP, the histologic features of SCAP can be contributing and immunohistochemical staining is useful. Our case shows the histologic variability of SCACP and the pitfalls of a punch biopsy for the diagnosis of SCACP.

Keywords: Adenocarcinoma; Cutaneous adnexal neoplasm; Lymph node metastasis; Pagetoid spread; Perianal area; Perianal syringocystadenocarcinoma papilliferum; Syringocystadenocarcinoma papilliferum.

Fig. 1

a Clinical appearance of the perianal tumor: a mass with a papillary surface within a background of erythematous-erosive plaque. b The specimen of the punch biopsy from the erythema: atypical cells with hyperchromatic nuclei were observed in situ. Hematoxylin-eosin staining of the resected tumor specimen showed the following: c Focal connection to the epidermis and papillary projections that protruded into the cystic space. d Apocrine differentiation with decapitation secretion. e The stroma contained infiltrative plasma cells and lymphocytes. f Areas of squamous differentiation in the epidermis. g Pale tumor cells with a pagetoid appearance were observed at all levels of the epidermis. h The invasive adenocarcinoma component.

Fig. 2

Immunohistochemical CK5/6 stainings. a CK5/6 was positive for the cells of the outer layer in the papillary projections. b Tumor cells with pagetoid spread showed heterogeneous staining for CK5/6. c The tumor cells were weakly positive for CK5/6 in the adenocarcinoma component.