Synovial sarcoma: clinical, morphological, immunohistochemical, and molecular-biological characteristics in outcome prediction

I n t r o d u c t i o n . Synovial sarcoma (SS) occupies a prominent place in the group of soft tissue sarcomas (STS) in terms of prevalence and clinical and biological aggressiveness, remaining one of the key nosologies in the adult population and a significant cause of cancer in adolescents and young adults.
A i m . To perform a comparative analysis of the clinical, morphological and immune characteristics of SS in children and adults, to describe the immunoarchitectural patterns of the tumor microenvironment and determine their relations with the disease course, risk of metastasis and survival rates, comparing the results obtained with data from international s tudies.
M a t e r i a l s a n d m e t h o d s . A single-center retrospective study of 140 patients (74 males and 66 females, aged 4 to 84 years) with morphologically confirmed SS, diagnosed in 2012–2024 based on the results of pathomorphological examination of primary (biopsy and surgical) and non-primary (“consultative”) tumor samples, was performed. Data from medical records, pathomorphological examination, and archival slides and paraffin blocks were analyzed.
R e s u l t s . The results obtained are generally consistent with the known epidemiological and morphological characteristics of SS: a peak in childhood and adolescence, a predominance of localized stages, frequent monophasic morphology, and a high rate of SS18::SSX-positivity. The analysis confirms that the “classic” risk factors – tumor size ≥5–7 cm, deep anatomical location of tumors in soft tissue, high mitotic activity, extensive areas of necrosis, FNCLCC grade 3, and positive resection margins – continue to determine the prognosis.
C o n c l u s i o n . A comprehensive pathological assessment of SS, including clarification of the morphological variant, standard prognostic parameters, and characteristics of the tumor microenvironment, appears to be appropriate for more accurate risk stratification in children and adults. This study, with complete morphological, immunohistochemical, and molecular verification of the diagnosis, can serve as a reference for the development of standardized pathological reports and prognostic models, as well as for planning multicenter studies for validating immune patterns and assessing their predictive value in the context of new approaches to immuno- and targeted therapy of SS.

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