Cytologic and histologic features of primary mucinous adenocarcinoma of skin in the axilla: a case report.Acta Cytol. 2007 Jul-Aug;51(4):571-4.

BACKGROUND: Primary mucinous adenocarcinoma of the skin is a rare tumor; its location in the axilla is rarer still. It closely mimics metastatic adenocarcinoma histologically. Owing to the good prognosis of the tumor, it is imperative that it is diagnosed or at least suspected to save the patient from unnecessary investigation and a radical treatment. Fine needle aspiration cytology (FNAC) is a very useful preoperative investigation for its diagnosis; however, cytologic description is not available in the literature so far. CASE: A 50-year-old man presented to the outpatient surgery department with a lump in the left axilla for 6 months. FNAC of the lump was done. The cytologic smears were hypercellular, with loosely dispersed cells in a background of pale pink material. On high-power examination, cells were monomorphic with plasmacytoid appearance and no atypia. Occasional mitotic activity was seen. A possibility of appendageal tumor was suggested and excision biopsy advised. On subsequent biopsy a diagnosis of primary mucinous adenocarcinoma of the skin was made. CONCLUSION: Because of the better prognosis of primary mucinous adenocarcinoma of the skin vis-a-vis metastatic adenocarcinoma; preoperative diagnosis is necessary. FNAC can serve as a rapid and accurate first-line investigation.