CYTO-HISTOPATHOLOGICAL STUDY OF SOFT TISSUE NEOPLASMS WITH RELEVANT IMMUNO-HISTOCHEMICAL STAINS

Abstract

Background: Soft tissue neoplasms (STNs) are a diverse group of tumors with varying behavior, ranging from benign to malignant. Due to overlapping features, accurate diagnosis can be challenging using cytology or histopathology alone. Immunohistochemical (IHC) staining helps in precise classification by identifying tumor origin and differentiation. This study highlights the role of combined cytohistopathological evaluation with relevant IHC markers in improving diagnostic accuracy of STNs.

Method: This four-year study (Jan 2012–June 2016) included both retrospective and prospective cases of benign and malignant soft tissue tumors diagnosed at a government tertiary care center in Maharashtra. Clinical, radiological, cytological, and gross findings were retrieved from histopathology records. FNAC was performed using 20–25G needles, and smears were stained with H&E, Pap, and Leishman stains. Gross specimens were evaluated for size, location, and morphological features. Tumors were classified and graded per WHO criteria. IHC was conducted on 3μm sections using enzyme-labeled antibodies and DAB chromogen. Data were analyzed using Primer of Biostatistics v7.0, with significance set at p < 0.05.

Results: In this study, out of 657 STTs, 93.6% were benign, 3.2% intermediate, and 3.2% malignant. STTs were most common in the 21–40 age group. Males were mainly affected in the third decade, females in the fifth. Adipocytic tumors were the most common subtype (67.28%), followed by peripheral nerve sheath tumors (14.92%). Among malignant STTs, tumors of uncertain differentiation (33.33%) were most frequent. The extremities were the most common site (43.22%). FNAC showed high accuracy with 9 true positives, 112 true negatives, 1 false negative, and no false positives.

Conclusion: Benign soft tissue tumors were overwhelmingly more common than malignant ones, with adipocytic tumors being the most frequent subtype. STTs predominantly affected young to middle-aged adults, with extremities as the most common site. FNAC proved to be a reliable diagnostic tool, showing high accuracy in differentiating benign from malignant lesions.