Unusual skin tumour with a large cystic component

An 80-year-old woman presented to our hospital with a tumour on the left lower leg. The lesion had slowly grown over the last year. She had no personal or family history of skin cancer. The lesion of concern was cystic and consisted of double 10 mm nodules in diameter. The clinical appearance of the lesion raised suspicion of malignancy and surgical resection was performed. The surgically-resected specimen was 22×15×14 mm in size, and the nodule had a yellowish serous fluid. 1. Nodular hidradenoma 2. Atypical hidradenoma 3. Hidradenocarcinoma 4. Poroma 5. Trichilemmoma Hidradenocarcinoma is an uncommon malignant tumour in a sweat gland. Generally, sweat gland carcinomas are rare with a reported incidence of approximately 0.05%. Hidradenocarcinomas account …