Syringocystadenocarcinoma Papilliferum: A Case Report and Review of the Literature

Abstract

Syringocystadenocarcinoma papilliferum (SCACP) is a rare malignant adnexal neoplasm, which is considered as a malignant counterpart of syringocystadenoma papilliferum (SCAP). Clinically, SCACP appears as a nodule, inflammatory plaque, or tumor. The lesion is usually covered with crusts, which are formed by secretion of the apocrine epithelial cells. Histologically, SCACP resembles SCAP, with cystic papillomatous invaginations connected to the skin surface by funnel-shaped structures lined by infundibular epithelium. The stroma of the tumor consists of a dense inflammatory infiltrate of plasma cells and lymphocytes. SCACP differs from SCAP in terms of the architectural and cytological features of the tumor cells, and is characterized by higher nuclear cytoplasmic ratio, nuclear irregularity, coarse chromatin, and increased mitotic activity. However, the immunohistochemical findings of SCACP vary. Since only 49 cases of SCACP have been reported in the English literature, the clinical and histologic characteristics of SCACP have not been fully established. Further studies on the diagnostic criteria for SCACP are warranted. Here, we report a rare case of SCACP and present a review of other relevant literature.

Keywords: Sweat gland neoplasm; Syringocystadenocarcinoma papilliferum; Syringocystadenoma papilliferum.

Fig. 1. Exophytic erythematous outgrowing plaque on perianal area.

Fig. 2. Biopsy from perianal area. (A) Tumor shows tubular and cystic configuration (H&E, ×40). (B) Wall of cystic structure shows papillomatous projections into cavity (H&E, ×100). (C) Tumor cells forming tubular structures show pale cytoplasm and large atypical nucleus with atypical mitoses. Stroma of papillae contains plasma cells and lymphocytes (H&E, ×400). (D) Tumor cells in epidermis show pagetoid spreads (H&E, ×400).