Oesophageal glomus tumours: rare neoplasms with aggressive clinical behaviour.

Aims: Glomus tumours are neoplasms with perivascular smooth muscle differentiation, which rarely occur in the oesophagus and may behave aggressively in this site based upon prior case reports. This study describes the clinicopathologic features of three oesophageal glomus tumours diagnosed at two large academic institutions between 1984 and 2022.
Methods and Results: Three cases of oesophageal glomus tumours were identified. Patients included two females and one male, with an age range of 19-65 years. All three tumours behaved in a malignant fashion, with metastases to various sites (lymph nodes, lung, pericardium, pleura, diaphragm, scalp). One patient developed an aorto-oesophageal fistula, resulting in a fatal haemorrhage. Tumours ranged in size from 4.5 to 8.1 cm. Histologically, all tumours had a multinodular, perivascular growth pattern. The neoplasms showed varying degrees of cytologic atypia and spindling, elevated mitotic activity (2-12 mitotic figures per 10 high-power fields), and necrosis was seen in in two cases. All tumours expressed smooth muscle actin by immunohistochemistry, and harboured NOTCH gene alterations (MIR143::NOTCH2 fusion in two cases; NOTCH3 rearrangement and NOTCH1 point mutation in one case). An ATRX splicing mutation in exon 10 was also identified in one case.
Conclusion: Oesophageal glomus tumours pose diagnostic challenges, given their rarity at this site, but can be recognised by their characteristic perivascular growth pattern, round central nuclei, and supportive ancillary studies. Given the propensity for aggressive behaviour in this location, we recommend management by a multidisciplinary sarcoma team for optimal outcome.
(© 2023 The Authors. Histopathology published by John Wiley & Sons Ltd.)