Primary Cutaneous Mucinous Carcinoma Presenting as an Unusually Large Lesion - A Rare Case Report

Abstract

Primary cutaneous mucinous carcinoma (PCMC) also known as primary mucinous carcinoma of the skin (PMCS) or primary mucinous eccrine carcinoma (PMEC) is a rare malignant adnexal tumour of eccrine origin. Many visceral mucinous carcinomas especially of the breast and gastrointestinal tract can metastasize to the skin mimicking PCMC. Hence it is very important to rule out metastatic mucinous carcinomas before making a diagnosis of PCMC. Usually, PCMC presents as a slowgrowing tumour of considerably smaller size compared to our case. The large size and shorter duration are the key features of this case report. Here we report an unusually large-sized rare malignant tumour of skin appendage. Our patient was a 54-year-old lady who presented with progressive swelling of one year duration in the right frontoparietal area. Ultrasonography showed an ill-defined lesion in the subcutaneous plane with multiple cystic spaces within it. No bone involvement was noted. The excised lesion measured 13 x 7 x 2 cms and was diagnosed as primary cutaneous mucinous carcinoma on histopathological examination. The possibility of cutaneous secondaries from elsewhere was ruled out by detailed clinical and radiological investigations. The case is reported considering the unusually bigger size and shorter duration of this rare entity.