[Solitary ulcer of the colon associated with mucosal melanosis].

The authors report on a case of solitary ulcer of the large bowel associated with mucosal melanosis, stressing the peculiar nature of this rare pathology and its differentiation from solitary ulcer of the rectum. The pathogenesis of the disease is still unknown and histological data from biopsies performed at various time intervals in chronic cases show, in this case as in other cases of solitary ulcer of the rectum, that histological findings vary over time; in the case reported on here, histology revealed a transition from a chronic inflammatory situation to one of mucosal melanosis after three months. Diagnosis is reached by exclusion and is based on colonoscopy plus biopsy. Useful techniques in complicated cases are selective angiography (for haemorrhage) or CAT (for perforations, abscesses). Treatment is conservative in uncomplicated cases, with suitable follow-up in the form of check colonoscopies and targeted biopsies. Surgical treatment is confined to those cases--by no means infrequent--complicated by haemorrhage, perforation and abscesses.