Endoscopic Ultrasound-Guided Fine-Needle Aspiration Findings of Gastrointestinal Leiomyomas and Gastrointestinal Stromal Tumors

Abstract

True leiomyomas of the gastrointestinal system are rare but remain the most common mesenchymal tumors of the esophagus. It has become important to distinguish these tumors from gastrointestinal stromal tumors (GISTs) because the neoplasms have different prognoses and treatment options. We describe and compare clinical findings and the following fine-needle aspiration (FNA) features of 9 gastrointestinal leiomyomas and 19 GISTs sampled with endoscopic ultrasound: overall cellularity, cell group features, cell shape and cytoplasmic features, nuclear characteristics, background, cell block features, and immunohistochemical results. Gastrointestinal leiomyomas and GISTs have different clinical and cytologic features that help pathologists distinguish these tumors, and the immunohistochemical findings that help define these lesions can be derived readily from cell block material obtained by endoscopic ultrasound-guided FNA.

Yield and Performance Characteristics of Endoscopic Ultrasound-Guided Fine Needle Aspiration for Diagnosing Upper GI Tract Stromal Tumors

“…In addition to providing specimens for cytology, EUS-FNA with immunohistochemistry studies assists in differentiating various submucosal tumors due to the preferential staining for several antigens including, c-kit for GISTs, smooth muscle actin for leiomyomas, and S-100 for schwannomas [1,7]. Data from large series, however, are lacking.…”

Pitfalls in Endoscopic Ultrasound-Guided Fine-Needle Aspiration and How to Avoid Them

“…107,108,111,114,115,118,127,128,130 Our own experience suggests that most GI mesenchymal neoplasms other than GISTs share cytologic features with their counterparts found in other locations throughout the body. 111,127,128 As is the case with peripheral FNA, cytologic features can be helpful for distinguishing one neoplasm from another (Table 6), although they may only rarely allow for a specific diagnosis with the exclusion of all other possibilities. For this reason, we again try to obtain material for cell block immunohistochemistry whenever we identify a spindle-cell tumor during rapid interpretation.…”

“…CD 117 (c-kit) staining is generally the most useful for distinguishing GISTs from other GI mesenchymal lesions. 107,108,[111][112][113][114]117,118,125,127,128,130 As most other lesions are true smooth muscle neoplasms, we also stain for smooth muscle antigens. To round out the battery, we usually include CD 34 and S-100, and only rarely are we forced to use any additional stains.…”

Endoscopic ultrasound-guided Trucut biopsy of gastrointestinal mesenchymal tumor

“…They have a benign histology and demonstrate uptake with smooth muscle actin, desmin, and, less commonly, CD34 (10-15%) on immunohistochemical stains. Leiomyosarcomas, however, are histologically high-grade lesions that express smooth muscle actin, desmin, or both [2].Gastrointestinal stromal tumors are spindle-cell or epithelioid mesenchymal neoplasms that can occur anywhere in the GI tract but most commonly arise in the stomach and …”

“…They have a benign histology and demonstrate uptake with smooth muscle actin, desmin, and, less commonly, CD34 (10-15%) on immunohistochemical stains. Leiomyosarcomas, however, are histologically high-grade lesions that express smooth muscle actin, desmin, or both [2].…”