Solitary Langerhans Cell Histiocytosis of the Palpebral Conjunctiva Presenting as Leukoplakia: Case and Review of Literature.

A 69-year-old male presented with a superior palpebral conjunctival white leukoplakic lesion. Excisional biopsy showed Langerhans cell histiocytosis. Positron emission tomography scanning revealed no lesions beyond this site. Native Langerhans cells are known to exist in the conjunctiva, yet only a few cases in the literature have described Langerhans cell histiocytosis of the conjunctiva, mostly in children. Conjunctival Langerhans cell histiocytosis has rarely been reported in an adult as leukoplakia. The authors advocate excisional biopsy for palpebral conjunctival Langerhans cell histiocytosis in older patients if the morbidity of closure is minimal, in addition to surveillance for multifocal disease.

Rosai-Dorfman Disease and Exocrine Pancreatic Insufficiency in a Patient With a Germline SLC29A3 Mutation.

Rosai-Dorfman disease (RDD) typically presents as bulky lymphadenopathy. Somatic mutations in RAS/MAP kinase pathway genes are common but germline mutations are rare. A patient with RDD and exocrine pancreatic insufficiency was found to have a homozygous germline mutation in SLC29A3, which has been associated with the Histiocytosis/Lymphadenopathy Plus Syndrome. His RDD also was positive for a somatic mutation in lymphoid enhancer binding factor 1 (LEF1). The concurrence of RDD and pancreatic insufficiency should raise consideration of SLC29A3 mutations. Other cases will be needed to confirm this observation and a possible contribution of LEF1 to the development of RDD.

Posterior mediastinal liposarcoma simulating a lung mass: an unusual case report.

Liposarcomas constitute approximately 15% of all sarcomas among the mesenchymal neoplasms. They usually arise in the lower extremities or in the retroperitoneum but have been reported in sites such as abdomen, vulva and buttocks. Primary mediastinal liposarcomas are rare with less than 100 cases reported worldwide so far. We present an interesting case of primary myxoid LPS of the posterior mediastinum with presenting complaints, imaging diagnosis and management with a review of the current literature.