title: Diffuse-type tenosynovial giant cell tumor in association with neurofibromatosis type 1-Noonan syndrome: possibly more than a chance relationship.
abstract: A case of diffuse-type tenosynovial giant cell tumor arising in the left upper extremity is reported in a 23-year-old man with neurofibromatosis type 1 (NF1)-Noonan syndrome. The predominately mononuclear cellular proliferation with psammomatous calcifications had the immunohistochemical and ultrastructural features of a fibrohistiocytic neoplasm. This uncommon type of soft tissue neoplasm occurring in this unique clinical setting served to open an inquiry into the subject of non-neurogenic tumors in association with NF1 and Noonan syndrome, both manifested in our patient. Nonossifying fibroma of bone as a presumptive fibrohistiocytic tumor is an uncommon but well-documented manifestation in NF1, whereas in Noonan-like syndrome, both giant cell granuloma and pigmented villonodular synovitis are recognized as associated lesions with histologic and immunophenotypic similarities with the diffuse-type tenosynovial giant cell tumor.
authors.affiliation: Lauren V. Ackerman Laboratory of Surgical Pathology MO, and Department of Orthopaedic Surgery, Washington University Medical Center, Barnes-Jewish Hospital, St Louis, MO 63110, USA.
authors.forename: Lorena
authors.initials: L
authors.lastname: Posligua
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: McDonald
authors.forename: Louis P
authors.initials: LP
authors.lastname: Dehner
mesh_terms: D000328:Adult; D001132:Arm / Q000473:pathology; D005870:Giant Cell Tumors / Q000150:complications* / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D046529:Microscopy, Electron, Transmission; D009456:Neurofibromatosis 1 / Q000150:complications*; D009634:Noonan Syndrome / Q000150:complications*; D012983:Soft Tissue Neoplasms / Q000150:complications* / Q000378:metabolism / Q000473:pathology*; D013710:Tendons / Q000473:pathology