Case: A 52-year-old male presented with a mass on the second digit of the distal phalanx. The patient underwent amputation after the diagnosis of adenocarcinoma with punch biopsy. At the amputation specimen the lesion had lobular, brown, soft appearance with bone invasion. Histologically the tumor had a cystic cavity with papillary projections and tubular structures. Vascular invasion and mitotic figures were seen. Because of the history of lung carcinoma, TTF1, Napsin A immunohistochemical stains were performed and no staining has been observed. S100 and CEA were predominantly positive.

Conclusion: Aggressive papillary adenocarcinoma is often missed due to the rarity of the lesion and this leads to wrong diagnosis with delayed and inadequate treatment. Effective surgery prevents local reccurrence. Here a case of aggressive papillary adenocarcinoma was presented with the clinical, morphological, immunohistochemical findings to keep in mind while evaluating the finger lesions. Anahtar Kelimeler : Aggressive papillary adenocarcinoma, Cutaneous adnexal tumor, Phalanx