[Pigmented or hemosiderotic atypical fibroxanthoma].

Pigmented atypical fibroxanthoma is a rare variant of atypical fibroxanthoma and is characterized by extensive areas of hemorrhage, erythrophagocytosis, and hemosiderin accumulation in the cytoplasm of the neoplastic cells. It affects elderly individuals and presents as irregularly pigmented, dome-shaped nodules or plaques on areas of skin exposed to the sun. We present a case of pigmented atypical fibroxanthoma on the cheek of an 81-year-old man.

[Methotrexate-associated lymphoproliferative disorder presenting as oral ulcers in a patient with rheumatoid arthritis].

Methotrexate-associated lymphoproliferative disorders are a heterogeneous group of lymphoid proliferations or lymphomas that develop in patients with autoimmune diseases treated using methotrexate. These lymphoproliferative disorders are often associated with Epstein-Barr virus infection and occasionally regress after the withdrawal of methotrexate therapy. The lymphoproliferative disorder in this case was diffuse large B-cell lymphoma, unusually presenting as oral ulcers in a 79-year-old woman on treatment with methotrexate for longstanding rheumatoid arthritis.

[Aquagenic keratoderma: 3 new cases and a review of the literature].

Aquagenic keratoderma is a rare type of transient acquired keratoderma that is triggered or exacerbated by immersion of the palms or soles in water. It is characterized by whitish or translucent papules with central punctate depressions that coalesce in macerated edematous plaques. It appears within a few minutes of exposure to water and subsides soon after drying.

Secondary amyloidosis associated with histiocytosis X.

We report a 34-year-old man diagnosed with Langerhans cell histiocytosis (LCH) or histiocytosis X in 1980. He had multiple focal osseous lesions, difficult control of the disease activity and was treated many times with chemo- and radiotherapy for symptomatic control. His kidney disease started 20 years after the diagnosis with progressive renal failure and increasing non-nephrotic proteinuria, coinciding with two flares of LCH.