Sarcomatoid mesothelioma is an aggressive disease secondary to its propensity to undergo rapid growth, show inconsistent expression of tumor markers and invade surrounding tissues. Therefore, there are numerous obstacles that clinical researchers face as they look for new methods to diagnose and treat the malignancy. We present a case of sarcomatoid mesothelioma, originally thought to be metastasis from renal cell carcinoma.

Adenocarcinoma is extremely uncommon in the digits with an incidence of 0.08 per 1 000 000 people per year, known as digital papillary adenocarcinoma (DPA). This disease is commonly described pathologically as malignancy of the sweat glands. The fundamental histologic characteristics of DPA are the presence of papillary projections in cystic spaces in a multinodular tumor lined by epithelial cells. DPA are often delayed in diagnosis because of either misdiagnosis for benign lesions or underreporting, which can contribute to poor prognosis and metastasis. This report serves to present a case of recurrence observed in primary digital adenocarcinoma and to bring awareness to the topic as concrete management continues to develop.