Isolated Langerhans cell histiocytosis of the stomach in adults: An analysis of clinicopathologic characteristics and molecular genetics.

Isolated gastric Langerhans cell histiocytosis (LCH) occurs extremely rarely in adults. We characterized the clinicopathological and molecular genetics of this rare entity. We retrospectively analyzed the clinicopathologic and prognostic features of 3 patients with isolated gastric LCH during the past 10 years, with a review of an additional 20 patients from the literature.

Giant cell tumor of bone with H3F3B mutation: A case report.

Rationale: Giant cell tumor of bone is a locally aggressive and rarely metastasizing neoplasm that typically affects the ends of long bones or the axial skeleton of young to middle-aged adults. As many as 69% to 100% of giant cell tumors harbor H3F3A gene mutations, while H3F3B gene mutations have rarely been reported.

Patient Concerns: A 53-year-old male patient who underwent right distal femoral tumor resection.

Primary intraosseous Rosai-Dorfman disease: An analysis of clinicopathologic characteristics, molecular genetics, and prognostic features.

Background: Rosai-Dorfman disease (RDD) is a rare histiocytic proliferative disorder of uncertain pathogenesis. Most patients present with proliferation in the lymph nodes manifesting as adenopathy; however, RDD may primarily arise in a variety of extranodal sites, including the bone, which is a great challenge in the diagnosis. The clinicopathological characteristics and prognostic features of primary intraosseous RDD have not been well characterized.