Abstract
BACKGROUND.
The role of endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) in the evaluation of spindle cell and mesenchymal lesions is unclear. This study reviews the use of EUS‐FNA in diagnosing intrathoracic and intra‐abdominal spindle and mesenchymal cell lesions at an academic institution.
METHODS.
All EUS‐FNA specimens with a significant spindle or mesenchymal cell component were retrieved. Follow‐up was comprised of clinical correlation, chart review, or evaluation of subsequent tissue specimens, including FNAs, biopsies, and/or surgical resections. Lesions were categorized as either inflammatory/reactive or neoplastic.
RESULTS.
Forty‐four EUS‐FNA specimens were retrieved from 39 patients (21 men and 18 women with a median age of 61 years [range, 20‐88 years]). Anatomic sites included 19 lymph node specimens, 15 gastrointestinal tract specimens, 7 pancreatic specimens, and 4 other anatomic site specimens. Twenty‐two cases were inflammatory/reactive lesions, including 17 granulomatous lesions and 5 cases of chronic pancreatitis. Twenty‐two cases were neoplastic, including 14 gastrointestinal stromal tumors, 2 smooth muscle tumors, 2 sarcomatoid carcinomas, 2 melanomas, 1 sarcoma, and 1 solitary fibrous tumor. A specific cytologic diagnosis was rendered in 30 cases (81%). Immunocytochemistry was performed on 21 neoplastic cases and contributed to the differential diagnosis in 18 cases. No false‐positive findings were encountered. Three false‐negative results were identified and were attributed to sampling error.
CONCLUSIONS.
Spindle cell neoplasms are rarely encountered on EUS‐FNA. The differential diagnosis encompasses a wide variety of benign and neoplastic entities. Correlation of cytomorphology and ancillary studies yields a high diagnostic accuracy of spindle cell and mesenchymal lesions on EUS‐FNA. Cancer (Cancer Cytopathol) 2010. © 2010 American Cancer Society.