A Challenging Diagnosis of HHV-8-Associated Diffuse Large B-Cell Lymphoma, Not Otherwise Specified, in a Young Man with Newly-Diagnosed HIV.

BACKGROUND Human herpesvirus-8 (HHV-8)-associated diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS), is a rare form of lymphoid malignancy. It poses unique challenges in diagnosis in the setting of human immunodeficiency virus (HIV) infection and concomitant multiorgan dysfunction. CASE REPORT We describe the case of a 26-year-old man who initially presented with pre-syncope and was found to have HIV, with a CD-4 count of 20 cells/µL. His initial clinical presentation was significant for nonspecific symptoms, isolated anemia, and bilateral pleural effusions without gross lymphadenopathy, which was initially attributed to acute HIV infection. However, his hospital course was complicated by anasarca, renal failure, liver dysfunction, pancytopenia, and microscopic hematuria, which required a more comprehensive diagnostic evaluation. Progressive pancytopenia prompted a bone marrow biopsy, which ultimately revealed HHV-8-associated DLBCL, NOS (HDN). We describe his complicated hospital course and eventual diagnosis of HDN. This patient's broad differential diagnoses and overlap among various clinical syndromes posed a significant diagnostic challenge. Additionally, his multiorgan failure limited his treatment options. CONCLUSIONS The management of HHV-8-associated DLBCL, NOS is complex, requiring a multifaceted approach to ensure prompt diagnosis and treatment, especially given difficulty in arriving at an accurate diagnosis due to the significant overlap with other lymphoproliferative disorders and lack of standardized treatment. We highlight the challenges and paucity of data available for management of HDN in the context of a diagnostically challenging case. We discuss the current limitations in diagnosis and treatment of this rare malignancy and the necessity of further investigation, especially in medically complex patients.

Uncommon Presentation of Post-Transfusion Purpura in an Elderly Male: A Case Report and Unique Alloantibody Identification.

BACKGROUND Post-transfusion purpura (PTP) is a rare delayed adverse event characterized by severe thrombocytopenia associated with mucosal bleeding and purpura. PTP is associated with the development of alloantibodies to human platelet antigens (HPAs) and should be distinguished from other thrombocytopenic syndromes. This report is of a 69-year-old man with refractory cardiogenic shock and thrombocytopenia 4 days following blood transfusion, diagnosed with post-transfusion purpura. CASE REPORT A 69-year-old man was admitted to a tertiary medical center with refractory cardiogenic shock. Four days after he received 1 unit of packed red blood cells, his platelet count plummeted from 147 K/uL to <2 K/uL within hours, associated with delayed presentation of notable hematuria and femoral catheter oozing. An extensive thrombocytopenia work-up, including an initial platelet antibody screen, was unrevealing. The patient was treated with supportive transfusions, dexamethasone, and intravenous immunoglobulin, with rapid platelet recovery. Post-transfusion purpura panel testing later identified anti-human platelet antigen-5b antibodies, confirming the diagnosis. CONCLUSIONS This report presents an unusual course and presentation of post-transfusion purpura in an elderly man. Unusual features of this case include male sex, hyper-acuity of thrombocytopenia, lack of prior transfusions, exam findings, identification of a less common alloantibody, and negative initial platelet antigen screening. This report highlights the importance of monitoring patients for post-transfusion adverse events. Although PTP is rare, rapid diagnosis and management are required to control this potentially life-threatening condition.

A New Pathologic KMT2B Variant Associated with Childhood Onset Dystonia Presenting as Variable Phenotypes among Family Members.

Background: KMT2B-related dystonia is a primarily childhood-onset movement disorder characterized by progressive dystonia, spasticity, and developmental delay. A minority of individuals possess an inherited KMT2B variant. Case Report: As a child, the proband experienced mild developmental delay and laryngeal dystonia which progressed to generalized dystonia. Patellar hyperreflexia, postural tremor, and everted gait were documented. Whole exome sequencing identified a heterozygous pathogenic KMT2B variant in the proband, proband's sister, and proband's mother who had milder presentations. Discussion: This novel KMT2B variant reflects intrafamilial variable expressivity in KMT2B-related dystonia. Further identification of variants will allow for better appreciation of the phenotypic spectrum.