Morphological features of naevoid melanoma: results of a multicentre study of the International Dermoscopy Society.

BACKGROUND: Naevoid melanoma (NeM), a rare variant of melanoma, can be difficult to detect as its clinical and histopathological morphology can simulate a naevus. OBJECTIVES: To describe the clinical and dermoscopic features associated with NeM. METHODS: Lesions with a histopathological diagnosis of NeM were collected via an e-mail request sent to all members of the International Dermoscopy Society. All lesions were histopathologically reviewed and only lesions fulfilling a set of predefined histopathological criteria were included in the study and analysed for their clinical and dermoscopic features. RESULTS: Twenty-seven of 58 cases (47%) fulfilled the predefined histopathological criteria for NeM and were included in the study. Clinically, 16 of the 27 NeMs presented as a nodular lesion (59%), eight (30%) as plaque type and three (11%) as papular. Analysis of the global dermoscopic pattern identified three types of NeM. The first were naevus-like tumours (n = 13, 48%), typified by a papillomatous surface resembling a dermal naevus. In these lesions local dermoscopic features included irregular dots/globules (46%), multiple milia-like cysts (38%) and atypical vascular structures (46%). The second type were amelanotic tumours (n = 8, 30%), typified by an atypical vascular pattern (75%). The third type consisted of tumours displaying a multicomponent pattern (n = 4, 15%), characterized by classical local melanoma-specific criteria. Two lesions (7%) were classified as mixed-pattern tumours as they did not manifest any of the aforementioned patterns. CONCLUSIONS: While NeMs may be clinically difficult to differentiate from naevi, any papillomatous lesion displaying dermoscopically atypical vessels and/or irregular dots/globules should prompt consideration for the possible diagnosis of NeM.

Pyoderma gangrenosum with spleen involvement and monoclonal IgA gammopathy.

A 46-year-old man with a 3-year history of pyoderma gangrenosum was admitted with ulceration (6 x 5 cm), on the right leg. Previously he had been treated with tapering doses of prednisone (maximum dose 1 mg/kg per day); however, he had had a few exacerbations following each taper of prednisone dose. Immunoelectrophoresis demonstrated monoclonal IgA gammopathy of lambda light chains. Abdominal echography and abdominal computed tomographic scan revealed multiple splenic abscesses. Treatment was started with oral prednisone (1 mg/kg per day) and cyclosporin (5 mg/kg per day) and 6 weeks later complete remission was achieved. Systemic involvement in pyoderma gangrenosum is very rare, and according to our knowledge there are only a few cases with spleen involvement.

Persistent erythema multiforme: a report of three cases.

Three cases of persistent erythema multiforme, two of unknown aetiology and one precipitated by influenza are reported. Lesions were widespread, mostly atypical in appearance and regressed in response to immunosuppressants (systemic steroids and/or azathioprine) or, in one case, to dapsone. One patient developed erythroderma responding eventually to etretinate. Histology in all patients was consistent with the mixed, epidermodermal pattern of erythema multiforme. There were no significant laboratory abnormalities nor marked symptomatology apart from itching. The persistent form appears to belong to the spectrum of erythema multiforme being heterogeneous with respect to inducing stimuli, including viral antigens, neoplastic or inflammatory disease or unknown causes. Whenever it is possible, treatment should be adjusted depending on the causative agent.