Track: Case Reports

Abstract:

Digital papillary adenocarcinoma (DPA) is a rare, aggressive adnexal neoplasm derived from eccrine glands that typically arises on a finger or toe. We present an unusual case of DPA in a 45-year-old male with a longstanding history of recurrent viral warts on bilateral middle fingers, treated intermittently with cryotherapy. In December 2022, the patient presented with a 1.3 x 0.9 x 0.6 cm lesion on the left third finger.  Excisional biopsy revealed a multinodular, cystic neoplasm with papillary architecture and ductal differentiation. Immunohistochemistry demonstrated CK7, p63, S100, CEA, and EMA positivity, supporting the diagnosis of DPA. Subsequent clinical examination revealed palpable axillary and epitrochlear lymphadenopathy with biopsy confirmed metastatic disease. The patient underwent left axillary and epitrochlear lymphadenectomies followed by adjuvant radiation therapy, completed in May 2023. In May 2024, a second suspicious skin lesion was identified on the right third fingertip, which was excised and diagnosed as DPA. This case illustrates the potential for multifocal and metachronous involvement in DPA and underscores the importance of long-term clinical surveillance.   Recent studies suggest a role of HPV-42 in DPA tumorigenesis. Reflex HPV testing may be warranted in patients with DPA, particularly those with a history of digital verrucae.