Primary cutaneous cribriform carcinoma: a rare apocrine tumour

Background: Primary cutaneous cribriform carcinoma (PCCC) is a rare apocrine tumour occurring in middle‐aged people. This neoplasm is often located on the limbs. The histopathological diagnosis is difficult, mainly because this tumour is exceptional. We, in this study, report a patient with PCCC. Case report: The patient was a 37‐year‐old man who presented with a nodule of the left knee. Results: Histopathologic findings showed an asymmetrical deep dermal tumour with a cribriform pattern. The aggregations of neoplastic cells were interconnected and varied in size and shape. The cells were arranged in solid nests or tubular structures. In the lumina of tubules, some papillary protrusion of basophilic cells was seen. The ductal elements were lined by cuboidal or cylindric cells with images of decapitation secretion. The nuclei of the neoplastic cells were pleomorphic. A wide excision was performed with sentinel inguinal node biopsy. After a 2‐year follow‐up, neither persistence at the local site nor metastasis was observed. Conclusions: Clinical and pathological features of PCCC are reviewed. Differential diagnoses, including cutaneous metastasis of adenocarcinoma, adenoid basal cell carcinoma and adenoid cystic carcinoma, are discussed.