Delayed diagnosis of adult-onset mastocytosis.

Urticaria pigmentosa is most frequently observed in children. The associated symptomatology in mastocytosis is vague and not always diagnostic, and Darier's sign is often negative, making the diagnosis challenging. We describe a case of a 61-year-old man with extensive brown papules and macules in different locations of the body that slowly progressed in the last 10 years with a previous anaphylactic reaction after an ant bite.

Indeterminate Cell Histiocytosis Mimicking Rosacea.

Indeterminate cell histiocytosis (ICH) is a rare proliferative disorder of histiocytes, which display morphologic and immunophenotypic characteristics of both Langerhans cell histiocytosis (LCH) and non-Langerhans cell histiocytosis (NLCH). We describe an unusual clinical presentation of ICH mimicking rosacea and provide a relevant review of the literature.

A Rare Presentation of Nodular Amyloidosis on the Lower Back.

Primary localized cutaneous amyloidosis (PLCA) occurs when amyloid is deposited only within the skin and there is no evidence of systemic involvement. Nodular amyloidosis is the rarest subtype of PLCA. It typically involves the acral regions but can sometimes present on the head and neck.

Anti-Thymocyte Globulin Prophylaxis Induces a Decrease in Naive Th Cells to Inhibit the Onset of Chronic Graft-versus-Host Disease: Results from the Canadian Bone Marrow Transplant Group (CBMTG) 0801 Study.

Anti-thymocyte globulin (ATG) is an established approach to decrease chronic GVHD (cGVHD), yet the exact mechanism is uncertain. To better understand the mechanism of action of ATG in preventing cGVHD, we evaluated the day 100 immune reconstitution of known cGVHD cellular biomarkers using patients from the randomized Canadian Bone Marrow Transplant Group (CBMTG) 0801 trial, which demonstrated a significant impact of ATG on cGVHD. In a separate companion biology study, we evaluated the impact of ATG prophylaxis on cGVHD cellular markers at day 100 in 40 CBMTG 0801 patients.