Fine-needle aspiration biopsy causing peritoneal seeding of a carcinoid tumor.

A rare complication of fine-needle aspiration biopsy (FNA) is needle tract seeding. Peritoneal seeding from FNA in the clinical setting is rarely reported. To our knowledge, this is the first case of peritoneal seeding of a neuroendocrine carcinoid tumor as a result of FNA. Peritoneal contamination and tumor seeding can occur with FNA and they probably do occur more often than is recognized clinically. Therefore, we caution against the use of FNA in the assessment of potentially curable intra-abdominal tumors, and recommend that this technique be used only when a cytological diagnosis is required before initiation of palliative therapy.