Carcinoma cuniculatum of the oesophagus and tongue – report of two cases, including TP53 mutational analysis

Abstract

We present two cases of carcinoma cuniculatum (CC), a very rare, most commonly cutaneous variant of extremely well differentiated squamous cell carcinoma. The tumours were located in the tongue (62-year-old male with enlarging chronic ulcer) and oesophagus (77-year-old male with progressive dysphagia and odynophagia). Both patients were treated surgically (hemiglossectomy and oe-sophagectomy). Histologically, both tumours were composed of deeply invaginating, keratin filled, focally dilated, burrowing channels lined by squamous epithelium which in the lingual tumour was very well differentiated, i.e., with no significant nuclear atypia/pleomorphism. The oesophageal tumour showed intratu-moural dense infiltration of neutrophilic granulocytes with varying degrees of nuclear atypia of the neoplastic squamous epithelium limited to the areas with acute inflammation. These atypical areas did not show any significant nuclear expression of p53 on im-munohistochemistry and no mutation of TP53 was identified after analysis of exons 2 to 11. Both tumours had presented differential diagnostic difficulties on previous biopsies. The patient with oesophageal tumour had no documented recurrence at 1 year and 2 months follow-up. The patient with the lingual tumour was recently diagnosed precluding any meaningful follow-up.