The value of a second expert opinion in histopathological diagnosis of bone and soft tissue sarcoma: a systematic review

Accurate subtype diagnosis of sarcoma is crucial for optimal patient management, requiring integration of clinical, radiological, morphological, immunohistochemical, and molecular findings. This systematic review examines the value of expert second opinions in the histopathological diagnosis of bone and soft tissue sarcomas. The review was conducted using the population, intervention, comparison, and outcome model over a 32-year timeframe. Notably, five studies reported major discrepancy rates exceeding 20%, impacting patient management or prognosis. Given these findings, we recommend referring all suspected sarcoma cases to specialised sarcoma centres for expert second opinions to ensure accurate diagnosis and optimal care. While all studies broadly addressed diagnostic discrepancy during second opinion review, there were difficulties in comparing the data from various studies. These difficulties related to the lack of standardised definitions of what constitutes (1) a second opinion, (2) a specialist pathologist in sarcoma, and (3) a discordant diagnosis.