Gastrointestinal stromal tumor with skeinoid fibers of the ileum

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%.

Fine-needle aspiration cytology diagnosis of metastatic gastrointestinal stromal tumor in the liver: a report of three cases

Gastrointestinal stromal tumor (GIST) is the designation for a major subset of gastrointestinal mesenchymal tumors that histologically, immunocytochemically, and genetically differ from leiomyomas, leiomyosarcomas, and schwannomas. GISTs derive from the interstitial cells of Cajal and, in addition to variable expression of smooth muscle and neural markers, they characteristically express CD34 and CD117. The cytological appearance, including immunocytochemical and mutational analysis of c-kit gene in primary GIST has been well described. To our knowledge, only two cases of metastatic GIST diagnosed by fine-needle aspiration (FNA) have been reported. We illustrate three cases of metastatic GIST in the liver. Two cases had no prior history of gastrointestinal tumor and the third case had a 4-yr previous history of duodenal tumor. Consistent immunocytochemistry and ultrastructual studies supported the diagnosis of GIST. We emphasize that in the appropriate clinical and radiological setting, a confident diagnosis of GIST can be established by FNA of metastatic lesions.

Cytologic diagnosis of gastrointestinal stromal tumors of the stomach by endoscopic ultrasound-guided fine-needle aspiration biopsy: cytomorphologic and immunohistochemical study of 12 cases

Gastrointestinal stromal tumor (GIST) is an uncommon tumor, which was usually diagnosed by endoscopic biopsy or surgical resection. This study evaluated the efficacy and accuracy of endoscopic ultrasound (EUS) -guided fine-needle aspiration (FNA) biopsy in the diagnosis of GIST and reported its cytomorphologic features. Twelve patients with gastric GIST were diagnosed through EUS-guided FNA. Immediate on-site evaluation and cytologic diagnoses were given in nine cases (75.0%) with an average of three passes. Cell blocks provided diagnostic material in three cases (25.0%). Spindle cells were present in the cytologic material in all cases. Two patients had subsequent surgical resections. Immunohistochemical (IHC) studies performed in cell blocks and two surgical specimens all supported the original diagnoses. In the two cases with surgical resections, IHC results in cell blocks were similar to that in the resected specimens. This study demonstrated that when combining smears and cell blocks, EUS-guided FNA is accurate and efficient in the diagnosis of GIST. IHC reactivity in cell blocks correlated with that of the main tumors.