[Nested melanoma]. / Mélanome en thèques.

BACKGROUND: Nested melanoma in elderly subjects is an entity that has been reported in the literature only since 2012. In this paper, we describe its distinctive clinical, dermatoscopic and histopathological features and compare them to previous published cases, with the aim of highlighting certain specific criteria of this melanoma subtype. CASE REPORT: A 52-year-old man was referred for the presence on his chest of a large suspicious pigmented lesion of irregular shape and colour. Dermatoscopically, the lesion was chaotic and characterized by a black, structureless, eccentric area with some peripheral globules as well as some segmental radial lines. Histopathological examination revealed the presence of an asymmetric lesion with large junctional melanocytic nests showing a focal tendency to gathering and some cytological atypia. A diagnosis of nested melanoma was ultimately made. DISCUSSION: Nested melanoma of the elderly represents a distinct anatomoclinical variant of superficial spreading melanoma. Clinically, the lesion is usually large and occurs in photodamaged skin. We would stress that the "elderly" criterion is not mandatory given the numerous cases reported in people under 60 years. The main dermatoscopic feature is a globular pattern, but several features characteristic of superficial spreading melanoma may also be present. Histological diagnosis may be difficult because of the mainly nested pattern, and the condition may be confused histologically with a benign junctional nevus. But these large junctional nests of different sizes, with bridging and cytonuclear atypias, together with asymmetry of the lesions are the hallmark of this special kind of melanoma.

[Primary localized cutaneous nodular amyloidosis: A diagnostic and therapeutic challenge]. / Amylose cutanée nodulaire primitive localisée: un défi diagnostique et thérapeutique.

BACKGROUND: Nodular primary localized cutaneous amyloidosis (PLCA) is a rare subtype of localized cutaneous amyloidosis in which amyloid protein is derived from immunoglobulin light chains. Follow-up for progression to systemic amyloidosis or autoimmune disease is mandatory. No consensus exists regarding treatment. PATIENTS AND METHODS: We report a case of nodular PLCA in a 49-year-old man, presenting as an asymptomatic nodule of the nose. Skin biopsy revealed diffuse deposition of amyloid associated with plasmocyte proliferation. Monotypic kappa light-chain restriction was observed. Extensive systemic evaluation, including bone marrow biopsy and PET scan, was negative. Protein electrophoresis and immunofixation in serum and urine were normal. The nodule was treated with radiotherapy but there was no response. Mohs micrographic surgery (MMS) was performed with no recurrence at 6 months of follow-up. No systemic progression was observed one year after the initial diagnosis. DISCUSSION: Since nodular PLCA may have a cutaneous presentation similar to that of primary systemic amyloidosis, evaluation for systemic amyloidosis is necessary. Treatment of amyloidosis is difficult. Radiotherapy appears ineffective in treating this type of primary cutaneous amyloidosis, and surgical treatment, where possible, is a good option, especially with MMS, which allows both controlled excision and minimal margins.