Primary thoracic extraskeletal osteosarcoma: a case report and literature review

Abstract

Primary extraskeletal osteosarcoma (ESOS) presenting in thoracic locations is very rare and associated with a poor prognosis. The current study presents a case involving a large anterior mediastinal mass, which was histologically confirmed as a primary osteosarcoma. The literature concerning primary thoracic ESOS is reviewed. A total of 60 cases were identified. The median age was 60 years (range, 14-93 years) and males were more prevalent among the reported cases (65%). Survival analysis revealed that the overall 5-year survival was only 22.3%. The majority of cases of thoracic ESOS presented in the lung (n=24, 40%), with others presenting in the mediastinum, pleura, or chest wall. The benefit of surgery, chemotherapy and radiotherapy was confirmed by Cox regression survival analyses.

ASCL1 represses a SOX9+ neural crest stem-like state in small cell lung cancer

“…In addition, a slow-growing bone phenotype would be under strong negative selective pressure to emerge compared with rapidly growing SCLC, and therefore this should be an extremely uncommon event. There are rare case reports of patients developing carcinoids with ossification (Tsubochi et al 2013;Özsȩn et al 2020) and extraskeletal osteosarcoma (ESOS) in the lung (Qian et al 2017), including one ESOS following chemotherapy treatment of SCLC (Takamura et al 2018), but these could represent secondary tumors. Given that ASCL1 repression of SOX9 is conserved, however, it is tempting to speculate that treatments that block ASCL1 potently in the clinic could push tumor evolution to a dedifferentiated NC stem-like state.…”

The Role of Chemotherapy in Extraskeletal Osteosarcoma: A Propensity Score Analysis of the Surveillance Epidemiology and End Results (SEER) Database

“…This study represents large cohorts of ESOS with 310 patients included based in the SEER database from 1976 to 2016. Because of the low incidence of ESOS, the majority of published studies concerning ESOS were case reports [ 27 – 29 ]. Median age was 60 years in the current study and most tumors were high-grade (grade III/IV), which was consistent with the common characteristics of ESOS [ 20 , 24 ].…”

ASCL1 represses a latent osteogenic program in small cell lung cancer in multiple cells of origin

“…A slow-growing bone phenotype would be under strong negative selective pressure compared to rapidly-growing SCLC, and therefore likely to be an extremely rare event. However, there are rare case reports of patients developing carcinoids with ossification 58,59 and extraskeletal osteosarcoma (ESOS) in the lung 60 , including one ESOS following chemotherapy treatment of SCLC 61 . It is tempting to speculate that treatments that block ASCL1 potently in the clinic, could push tumor evolution to a bone-like fate, or more likely, to a faster-growing dedifferentiated MSC or NC stem cell-like state.…”