VATS as a Diagnostic Lifeline in Occult Pleural Metastasis from a Long-Standing Low Grade Fibromyxoid Sarcoma of the Elbow: A Rare Case Report

DOI

No Doi

Published In

Year 2026 · Volume 1 · Issue 2

Published Online

May-August 2026

Pages

70-79

Article Type

Case Report

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Background: Low Grade Fibromyxoid Sarcoma (LGFS) is a rare soft tissue sarcoma notorious for its deceptively bland cytological appearance and capacity for late distant metastasis despite prolonged clinical indolence. Pleural metastasis from LGFS is an exceedingly rare event with very limited documentation in the literature. We present a case in which Video-Assisted Thoracoscopic Surgery (VATS) served as the definitive and irreplaceable diagnostic tool, unmasking Stage IV LGFS in a patient whose disease had gone undetected for 15 years. Case Summary: A 36-year-old female presented to Surgical Oncology OPD with the sole complaint of a gradually progressive swelling over the medial aspect of the left elbow for 15 years. FNAC had previously reported a mesenchymal spindle cell tumor of benign/borderline nature. Chest X-ray performed as part of pre-operative workup for planned wide local excision incidentally revealed massive left-sided pleural effusion. Intercostal drainage (ICD) with comprehensive pleural fluid analysis — cytology, ADA, CBNAAT, culture — was entirely non-diagnostic. The effusion recurred. CECT thorax revealed multiple pleural nodules with hydropneumothorax. Ultrasound-guided tissue sampling failed. Following systematic failure of all non-invasive and minimally invasive diagnostic approaches, VATS was performed. Direct thoracoscopic visualization revealed multiple diffuse pleural nodules; excisional biopsies confirmed a metastatic spindle cell neoplasm on HPE. IHC (Medanta Labs, Biopsy No. B/9131/2026): Vimentin positive, Ki-67 5-6%, CD34/STAT-6/SMA/Desmin/Calretinin/S-100 all negative — consistent with Low Grade Fibromyxoid Sarcoma. MUC-4 IHC is positive as the confirmatory marker. Conclusion: This case powerfully demonstrates that VATS is the definitive diagnostic intervention when all non-invasive approaches to pleural disease fail. It further highlights the notorious cytological treachery of LGFS, the inadequacy of FNAC for soft tissue sarcoma diagnosis, and the imperative of long-term surveillance for all soft tissue tumors regardless of apparent clinical indolence.