Glioma-associated oncogene homolog 1-altered mesenchymal tumour of the upper oesophageal sphincter.

Glioma-associated oncogene homologue 1-altered mesenchymal tumours (GLI1-AMT) are rare, recently characterised soft tissue neoplasms driven by GLI1 fusions or amplifications. They predominantly arise in the head and neck, though their full clinicopathological presentation remains variable.A female in her 30s with a year-long history of progressive dysphagia was found to have a GLI1-AMT of the upper oesophageal sphincter, the first known case at this site. She underwent laser excision of the mass with adjuvant radiotherapy with no disease recurrence to date.Literature review identified 42 additional cases in the head and neck, most commonly affecting the tongue. Genetic alterations include GLI1 amplifications, frequently co-amplified with CDK4 and MDM2, and fusions, typically with ACTB, PTCH1 or MALAT1. Immunohistochemical staining patterns are inconsistent, though CD56, S100 and MDM2 are frequently positive.Classification of GLI1-AMT has evolved over recent years, and research is needed to refine diagnostic criteria and elucidate the behaviour of this spectrum of neoplasms.