Besides being an uncommon clinicopathological entity, interstitial granulomatous dermatitis, also described as interstitial granulomatous dermatitis with arthritis (IGDA), has shown a wide spectrum of clinical manifestations, such as linear and erythematous lesions, papules, plaques and nodules. Histological features include dense dermal histiocytic infiltrate, usually in a palisade configuration, and scattered neutrophils and eosinophils. We describe a middle aged woman with rheumatoid arthritis of difficult management and cutaneous lesions compatible with IGDA.

Targetoid Hemosiderotic Hemangioma, also known as Hobnail Hemangioma, is a lesion of vascular origin, probably lymphatic. The most common clinical feature is a solitary violaceous papule surrounded by a pale, thin area and a peripheral ecchymotic ring, simulating a target. Histopathologically, there is a biphasic pattern, with dilated vessels in the superficial dermis and pseudoangiosarcomatous pattern in the deep dermis, and endothelial cells with hobnail morphology. A simple excision is curative. We report a rare case of Targetoid Hemosiderotic Hemangioma.

Amyloidosis is part of a group of deposition diseases. Nodular amyloidosis is a rare form of primary cutaneous amyloidosis. It affects men and women, usually over the age of 60 years. Presenting manifestation of the disease are yellowish-erythematous or brownish nodules or plaques in single or multiple infiltrates. Systemic evaluation should be performed to rule out involvement of other organs. Follow-up of the patient is important because the condition may progress to systemic amyloidosis. We report a case of nodular amyloidosis in which the lesion had a corymbiform aspect without systemic involvement and no recurrence after two years of follow-up. Keywords: Amyloid; Amyloidosis; Congo red Resumo: As amiloidoses constituem um grupo de doenças de depósito. A amiloidose nodular é uma forma rara de amiloidose cutânea primária. Acomete homens e mulheres, geralmente acima de 60 anos. Apresenta-se com nódulos ou placas eritemato-amareladas ou acastanhadas infiltradas isoladas ou múl-tiplas. A avaliação sistêmica deve ser feita para descartar comprometimento de outros órgãos. É importante o seguimento devido a possibilidade de evolução para amiloidose sistêmica. Relatamos um caso de amiloidose nodular com lesão de aspecto corimbiforme sem sistematização e sem recidiva após dois anos de seguimento.

Palpable migratory arciform erythema is an entity of unknown etiology, with few published cases in the literature. The clinical and histopathological features of this disease are difficult to be distinguished from those of Jessner’s lymphocytic infiltration of the skin, lupus erythematous tumidus and the deep erythema annulare centrifugum. We describe here the first two Brazilian cases of palpable migratory arciform erythema. The patients presented with infiltrated annular plaques and erythematous arcs without scales. These showed centrifugal growth before disappearing without scarring or residual lesions after a few days. They had a chronic course with repeated episodes for years. In addition, these cases provide evidence of a drug-induced etiology.