Kaposi sarcoma in association with an extracavitary primary effusion lymphoma showing unusual intravascular involvement: report of case harboring a FAM175A germline mutation
Abstrakt
Primary effusion lymphoma (PEL) is a rare form ofaggressive B-cell lymphoma characterized by a malignant serouseffusion involving body cavities. It usually associated with humanherpes virus-8 (HHV-8) and coexpression of Epstein-Barr virus andmostly affects patients with HIV.
We report a rare case of cutaneousPEL with an unusual intravascular presentation, combined withKaposi sarcoma involving the skin, lung, and gastrointestinal tract.The molecular genetic analysis of the sarcoma and lymphomacomponents, using next-generation sequencing was performed. Thepatient was a 67-year-old man who presented with multiple cutane-ous tumors and mass in the left lung.
He died 17 hours after theadmission to the hospital. At autopsy, in addition to the cutaneouslesions, tumors in the left lung and gastrointestinal mucosa weredetected, and no effusions in the body cavities were seen.
The biopsyfrom the cutaneous lesions, pulmonary, and intestinal tumors re-vealed histological and immunohistochemical features of Kaposisarcoma. In addition, the skin biopsy specimens contained a diffuseinfiltrate composed of large pleomorphic cells, with focal intravas-cular growth that were negative for pan B-cell markers, weaklypositive for CD38 and CD138 but expressed CD3, HHV-8, andEpstein-Barr virus.
Molecular genetic studies in this specimen re-vealed monoclonal rearrangements of the IgH gene. The diagnosis ofPEL, solid variant, was made.
Next-generation sequencing analysisof the tumorous and normal tissue detected a pathogenic germlinemutation of theFAM175Agene and somatic mutations inBRCA2andRAD51B(in both sarcoma and lymphoma specimens), andINPP4BandRICTOR(in lymphoma specimen only).