title: Solitary reticulohistiocytoma in pregnancy: immunohistochemical and ultrastructural study of a case with unusual immunophenotype.
abstract: A case of a solitary reticulohistiocytoma during pregnancy is reported. The tumor arose on the right thigh of a 31-year-old woman during the 2nd month of gestation. Physical examination 6 months later revealed a 9 x 6 mm yellowish white papule. A biopsy showed a dermal proliferation of spindle to polygonal cells embedded in fibrous tissue with admixed neutrophils, eosinophils, and lymphocytes. Immunohistochemistry was positive for S-100, factor XIIIa, HLA-DR, KP-1, vimentin, and neuron-specific enolase. Ultrastructurally, the cells showed abundant lipid, lysozomes, and endoplasmic reticulum. No Birbeck granules could be identified. The results suggest an aberrant immunophenotype intermediate between indeterminate cells and dermal dendritic cells. The relationship of these lineages to reticulohistiocytoma and other dermal proliferative disorders is reviewed.
authors.affiliation: Division of Dermatology, UCSD Medical Center, San Diego, CA 92103-8420, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Hunt
authors.forename: S S
authors.initials: SS
authors.lastname: Shin
mesh_terms: D000328:Adult; D005260:Female; D015616:Histiocytosis, Non-Langerhans-Cell / Q000473:pathology*; D006801:Humans; D016130:Immunophenotyping; D011247:Pregnancy; D011248:Pregnancy Complications / Q000473:pathology*; D012871:Skin Diseases / Q000473:pathology*