A Case of Primary Cutaneous Cribriform Carcinoma on the Back

Primary cutaneous cribriform carcinoma (PCCC) is a rare and under-recognized sweat gland tumor that primarily presents as a subcutaneous
nodule on the extremities of middle-aged individuals. The main histopathological features are anastomosing tubules and solid nests producing
a sieve-like appearance. PCCC is regarded as an apocrine tumor based on the observation of decapitation secretion in the neoplastic cells. A
57-year-old female presented with an asymptomatic firm nodule on the back. The lesion gradually increased in size and hardened. Histopathologic
examination revealed encapsulated, circumscribed dermal nodule composed of atypical epithelial cells in a cribriform-like pattern. There were
occasional atypical mitotic figures and nuclear pleomorphism of the cells within the cribriform ducts and solid nests. In the immunohistochemical
analysis, stromal cells were weakly positive on SMA stain, but there was no evidence of a myoepithelial layer on either hemotoxylin or eosin-stained
sections or by immunohistochemistry with p63 and SMA. The possibility of cribriform-patterned metastasis from primary visceral carcinoma
was excluded by the breast ultrasonography, abdominal ultrasonography, endoscopic exams, and whole body fusion PET-CT. Wide excision was
performed for the treatment and the postoperative site has been stable without any recurrence. Herein, we introduce this as a rare case of PCCC
on the back.