Ultrastructure of oesophageal melanocytosis

Abstract

Four examples of an endoscopically detected oesophageal melanotic lesion were examined by light microscopy, light microscope histochemistry and transmission electron microscopy, and were compared with 13 control samples of normal oesophageal epithelium. By light microscopy, pigmented melanocytes lacking atypia and mitoses were observed amongst the keratinocytes in the basal layer of the oesophageal mucosa. Junctional activity was absent. The mechanism of pigmentation was studied and found to consist of: an increase in the number of melanocytes in the basal layer of the mucosa, an increase in the quantity of melanin in these melanocytes, transfer of melanin from melanocytes to keratinocytes and to macrophages and fibroblasts in the tunica propria. Since all the lesions demonstrated increased numbers of both melanocytes and melanosomes, the term oesophageal melanocytosis rather than melanosis is suggested, to emphasise the essential character of the lesion as a cellular proliferation. The value of sampling these pigmented lesions during endoscopy is emphasised as a means of obtaining well-preserved material for the evaluation of a lesion which some authorities have viewed as a possible precursor for oesophageal malignant melanoma.

Melanosis of the Urinary Bladder in a Cow

“…2 Compound melanosomes have never been reported in melanosis of the urinary bladder. Indeed, these complexes were welldocumented by Yamazaki et al 13 in melanosis esophagi in man, with which our case shares many ultrastructural findings. We detected the presence of BPV-2, a common agent responsible for severe bladder pathology in cattle, including cancer.…”

Melanocytosis of the oesophagus: case report

“…Genellikle özofagus orta ve alt 1/3'lük kısmında görülmektedir (1,2). Nadir görülen ancak iyi tanımlanmış bir antitedir.…”

Coexistence of esophageal blue nevus, hair follicles and basaloid sqamous carcinoma: A case report

“…However, the proliferation of melanocytes might also arise from the scattered stromal neuroectodermal cells or from pluripotent epithelial stem cells [2] . The proliferation of melanocytes is rarely observed with an estimated incidence of about 0.07%-0.15% in patients undergoing endoscopy [3] . Results of a recent study [2] and our case, however, indicate that melanocytes are much more frequently seen in association with reactive changes in the squamous epithelium, such as chronic esophagitis.…”

“…This phenomenon was first described in 1963 by De la Pava, who found melanocytes in 4% of his autopsy material from the esophagus [1] . Subsequent studies showed that the incidence of esophageal melanocytes ranges 2.5%-8% [2,3] . The increased number of esophageal melanocytes along the epithelio-stromal junction is considered benign and has been described in association with chronic esophagitis, squamous epithelial hyperplasia and infiltrating squamous carcinoma of the esophageal mucosa [2] .…”