Oesophageal hyperkeratosis: clinicopathological associations.

AIMS: Oesophageal hyperkeratosis is rarely described. In contrast to hyperkeratosis of orolaryngeal mucosa, where its risk factors and association with squamous neoplasia are well-studied, the prevalence and clinicopathological features of oesophageal hyperkeratosis are unknown. METHODS AND
RESULTS: We reviewed prospectively 1845 oesophageal biopsies and found hyperkeratosis in 37 (2.0%). Among 98 patients studied, hyperkeratosis occurred in two distinct settings: group 1 [within Barrett's oesophagus (BO)/adenocarcinoma, n = 61, 62%] and group 2 (outside BO/adenocarcinoma, n = 37, 38%). In contrast to group 1, hyperkeratosis in group 2 was more often multifocal (>3 foci in 51% versus 16%, P = 0.0001), involved mid-oesophagus (51% versus 2%, P < 0.0001), showed endoscopic leucoplakia (24% versus 3%, P = 0.003) and involved current/former alcohol users (51% versus 19%, P = 0.0012). Importantly, invasive squamous carcinoma and squamous dysplasia were seen only in group 2 (47% and 19% versus 0%, P < 0.0001). Further, 42% of group 2, but none of group 1, had benign or malignant squamous lesions of the oral cavity/larynx (P < 0.0001).
CONCLUSION: Hyperkeratosis involves ~2% of oesophageal biopsies and can be divided into cases occurring within BO/adenocarcinoma and those occurring outside BO/adenocarcinoma. The former lack clinical significance, whereas the latter are associated frequently with oesophageal squamous neoplasia and squamous pathology of the head and neck region.