Percutaneous image-guided fine-needle aspiration of peritoneal lesions.

Fine-needle aspiration (FNA) is a widely accepted technique for the initial tissue diagnosis of a variety of lesions arising within retroperitoneal and intraabdominal viscera. Fear of complications secondary to perforation of the bowel wall has limited the use of FNA in the diagnosis of gastrointestinal and peritoneal masses. A variety of primary and secondary neoplasms involving the peritoneum may present as multiple nodules, as masses, or as diffuse involvement of the peritoneum. When these lesions are associated with mass lesions or areas of significant peritoneal thickening, they become amenable to percutaneous image-guided FNA. We report on our experience with a series of 23 peritoneal lesions investigated by FNA for which subsequent histologic confirmation was available in 19, along with an additional 4 cases without histologic confirmation. One to four passes were made into each lesion, and immediate assessment for adequacy was performed by a cytopathologist in all cases. All 17 cases with a specific cytologic diagnosis and histologic confirmation represented either primary or metastatic neoplasms (5 gastrointestinal stromal tumors, 4 metastatic melanomas, 2 mesotheliomas, 1 lymphoma, 1 example of Kaposi's sarcoma, 1 serous papillary carcinoma of ovarian origin, 1 mucinous adenocarcinoma of ovarian origin, 1 intraabdominal desmoplastic small-cell tumor, and 1 solitary fibrous tumor of the peritoneum). In an additional 4 cases, the aspirates were judged as insufficient for diagnosis, with the smears containing only blood and benign mesothelial cells and/or inflammatory cell elements. These four smears were associated with both neoplastic and nonneoplastic lesions. Surgical confirmation was obtained in only 2 of these cases (1 metastatic melanoma and 1 example of omental and peritoneal involvement by an ovarian adenocarcinoma). Two cases without histologic confirmation were associated with clinically confirmed metastases. In our series, no acute or chronic postprocedural complications were identified, indicating that FNA in this setting is a safe technique. Accurate cytologic diagnosis was achieved in 74% of cases. The overall insufficiency rate was 26%.