Case: A male in 70s had an incidental subcarinal mass on CT. The ovoid, well-circumscribed mass (64 × 50 × 41 mm) showed heterogeneous peripheral enhancement and displaced the oesophagus anteriorly, favouring a neurogenic tumour. Macroscopically, the specimen comprised lobulated tan fragments (up to 95 mm; 90 g). Microscopically, the mass comprised spindle-cell arranged in sweeping fascicles arising within/adjacent to muscularis propria. Mitotic activity was low (1/5 mm 2 ), with no necrosis. Immunohistochemical stains showed diffuse KIT (CD117), DOG1 and CD34 positivity; negative for pancytokeratin, S100/SOX10, desmin/SMA, STAT6, ALK, myogenin and β-catenin; retained H3K27me3 and Ki-67 ∼5%. Subcarinal lymph nodes were negative for malignancy. Findings supported oesophageal gastrointestinal stromal tumour (GIST).
Song et al. (Sun,) studied this question.