Aggressive digital papillary adenocarcinoma: a report of two diseases and review of the literature.

Aggressive digital papillary adenocarcinoma (ADPAca) is a rare, underreported, and often misdiagnosed malignant tumor of the sweat glands most commonly occurring in males in their fifties to seventies. We report two cases of ADPAca with important clinical implications. A 54-year-old man presented 3 years after digit amputation for ADPAca with new blue nodules on his arm, lymphadenopathy, and a lung nodule; he was diagnosed with and treated for metastatic ADPAca. He underwent chemotherapy, but died 4 months later. A 15-year-old boy presented with an enlarging tumor on his finger occurring after a trauma 3 years earlier. The tumor was suspected to be a deep fungal infection or pyogenic granuloma; however, results of excisional biopsy revealed an ADPAca. The patient underwent amputation and sentinel lymph node examination. No signs of metastases were found, and he is alive and well. These cases highlight both the importance of high clinical suspicion of digital tumors, even in children, enabling prompt diagnosis and treatment and also emphasize the metastatic potential of the tumor and the need for aggressive treatment and close long-term follow-up.