Digital Papillary Adenocarcinoma at the Site of 5 Years of Recurrent Paronychia: Case Report and Literature Review.

Digital papillary adenocarcinoma (DPA) is a rare malignant eccrine tumor often misdiagnosed as a benign condition. A 57-year-old Caucasian male with recurrent paronychia and a subcutaneous mass on the distal phalanx of the right fourth digit was diagnosed with DPA after seeking hand surgery evaluation 5 years following onset. A marginal excisional biopsy was positive for Staphylococcus aureus infection and DPA, leading to surgical excision with transmiddle phalangeal amputation for negative margins. DPA, while rare, often presents insidiously, leading to delayed diagnosis and increased risk of metastasis. This tumor has high rates of recurrence and metastasis, most commonly to pulmonary and lymphatic sites. Accurate diagnosis of DPA is challenging due to its resemblance to multiple benign cutaneous conditions. Current treatments focus on surgical excision, with an emphasis on negative margins. Sentinel lymph node biopsy is not routinely performed, although guidelines are difficult to establish due to the rarity of DPA. Diagnosing and treating DPA minimizes metastasis and recurrence. DPA should be considered in patients presenting with recalcitrant or recurring cutaneous lesions. Surgical management remains the primary treatment strategy, with ongoing research needed to optimize treatment protocols and follow-up care.