Primary orbital melanoma arising in an atypical diffuse (plaque-like) blue naevus/melanocytosis: a case report and review of literature

Background Primary orbital melanoma is a rare disease and can occasionally develop from a pre-existing neoplasm of the blue naevus family of melanocytic lesions. Case presentation Herein we report a rare case of primary orbital melanoma arising from an unusual atypical diffuse (plaque-like) blue naevus/melanocytosis. A 27 year old man presented with mild pain and swelling of the left eye. Magnetic Resonance Imaging revealed a left lateral episcleral orbital mass and an incisional biopsy confirmed the diagnosis of malignant melanoma. Skin-sparing total left orbital exenteration was performed. Histopathological examination of the exenteration specimen revealed a primary orbital melanoma arising in a pre-existing blue naevus like melanocytosis. We demonstrate the evidence for histological progression, characterise the molecular profile of this tumour and discuss the related literature. Conclusions This case emphasises the importance of a meticulous clinicopathological correlation in recognising such a tumour as a primary orbital melanoma rather than a metastasis, which is managed differently.

Post radiotherapy, blue naevus conversion to basal cell carcinoma

<p class="abstract">Post-radiation conversion of benign cutaneous lesions to malignant is likely in the facial region. Thereby counselling and necessity of regular follow up is essential in patients undergoing radiotherapy in head and neck malignancies. Benign lesions undergo malignant change more so in the fascio cutaneous planes. A benign nasomaxillary blue naevus that transformed to malignant basal cell carcinoma following radiotherapy for pituitary adenoma is being reported.</p>

Blue, grey, and black colouration

Normal ethnic skin colouration is due to melanin in the skin. However, in this short chapter abnormal blue, grey, or black changes in skin colour, both localized or generalized, are discussed and illustrated by a few clinical images. The Mongolian blue spot that occurs as a physiological change in the skin of the majority of Asian, Black, and Chinese infants is due to melanin. It is uncommon in Caucasian skin types and not always recognized. A good illustration of the relatively common blue naevus is provided and much rarer examples discussed such as naevus of Ota, naevus of Ito, and alkaptonuria. In addition to melanin, other chromophores deposited in the skin may appear blue or black, such as haemoglobin or rarely drug deposits. The popularity of tattoos and associated problems are also mentioned.