Sarcomas in fluid cytology: Experience from a tertiary care centre in India

Abstract

Cytological evaluation of fluids for sarcomatous exfoliation is extremely rare. However, recently studies have come up describing characteristics of sarcomatous malignancies exfoliating into fluids but study from an Indian experience is still lacking. Description of clinico-pathological landscape in known cases of sarcomas, involving body fluid with emphasis on cytomorphologic details. Study includes cases reported as positive for involvement by sarcoma on fluid cytology including pleural, ascitic and cerebrospinal fluid (CSF) specimens between Jan 2016 to June 2022. Cases were retrieved and reviewed for cytomorphologic features which were subsequently correlated with its parent histology and IHC. IHC was applied on cell blocks for two cases where involvement was doubtful. In total, 21 fluid samples/cases including 4 CSF, 6 ascitic and 11 pleural fluid specimens were incorporated. Case spectrum comprised of 6 cases of Ewing Sarcoma (ES), 3 cases of rhabdomyosarcoma (RMS), 3 cases of osteosarcoma (OS), 2 cases of malignant peripheral nerve sheath tumor (MPNST), 2 cases of synovial sarcoma (SS), a case each of chondrosarcoma (CS), leiomyosarcoma (LMS) angiosarcoma (AS) and two cases of other malignancies with exfoliation of their sarcomatous component. Two cases presented as isolated latent metastasis so an IHC panel was applied to exclude involvement by secondary malignancy and prove involvement by primary diagnosed sarcoma.Majority of exfoliated sarcomas presented with epithelioidto pleomorphic morphology where at times it becomes obligatory to rule out occurrence of a secondary malignancy. It’s the first study from an Indian institute’s perspective that reflects upon such diversity of sarcomas with variability in morphology on exfoliation which can be overwhelming for a cytopathologist at times. IHC panel might be used when clinical background is unknown or when involvement is uncertain. More studies are needed that can help come up with recommendations that address such problems.