Intestinal GIST masquerading as an ovarian mass: Diagnosed on FNAC

The preoperative diagnosis of metastatic intestinal gastrointestinal stromal tumors (GIST) on cytology can be quite difficult at times. The present case characterizes the cytomorphological and immunocytochemical features of GIST, emphasizing the utility of fine-needle aspiration cytology (FNAC) in the evaluation of spindle cell tumors of gastrointestinal tract. An accurate and early diagnosis of GIST affects the treatment, primarily allowing the use of tyrosine kinase inhibitors in unresectable or metastatic cases. Presence of highly cellular fragments of spindle-to-oval cells with variable degree of pleomorphism, atypia, and necrosis supplemented by immunocytochemistry can render a cytological diagnosis of GIST in dilemmatic clinical situations. Our case highlights the diagnostic role of FNAC in the evaluation of a pelvic mass, which was clinicoradiologically misdiagnosed as ovarian carcinoma.