Juvenile systemic lupus erythematosus (jSLE) is a rare disorder that presents with greater severity compared to adult systemic lupus erythematosus. It typically manifests in adolescent females with constitutional symptoms, multisystem involvement, and a malar rash. In this case, a 9-year-old African American pre-pubertal girl presented with a progressive facial and scalp rash, weight loss, night sweats without fever, and abdominal pain following recent penicillin exposure. On laboratory results and clinical examination, leucopenia, auricular chondritis, palatal ulceration, and marked facial rash were found on physical exam and initial lab testing, alongside a negative infectious disease workup. Autoimmune workup demonstrated an elevated antinuclear antibody and anti-double-stranded DNA with low complement levels. Therefore, she met diagnostic criteria for jSLE. She improved rapidly with corticosteroids. Over the following year, she subsequently developed lupus nephritis. This case illustrates an atypical presentation of jSLE with early-onset prior to puberty and uncommon features, including chondritis, discoid lesions, and isolated mucocutaneous symptoms, with no associated joint pain or organ damage at initial presentation. Atypical jSLE presentations require high clinical suspicion to prevent delayed diagnosis and progression to complications such as lupus nephritis.

A 16-year-old girl presented with a three-month history of progressive, painless, bilateral periorbital edema without renal, hepatic, thyroid, or allergic etiology. Physical examination revealed bilateral periorbital puffiness without erythema, tenderness, malar rash, synovitis, or peripheral edema. Laboratory studies demonstrated a hemoglobin level of 8.3 g/dL, erythrocyte sedimentation rate of 115 mm/hr, serum albumin at 2.6 g/dL, antinuclear antibody greater than 400 AU/mL (normal: <40), and anti-double-stranded DNA antibody greater than 800 IU/mL. Urinalysis and 24-hour urinary protein excretion (120 mg/day) were normal. Abdominal ultrasonography revealed moderate ascites with normal liver parenchyma, portal vein caliber, and renal architecture. Chest radiography demonstrated no pleural effusion or other cardiopulmonary abnormality. A clinical diagnosis of probable systemic lupus erythematosus was made based on strongly positive autoantibodies, active systemic inflammation, unexplained anemia, and moderate ascites with hypoalbuminemia in the absence of alternative etiologies. The combination of hypoalbuminemia, ascites, and absent proteinuria raised suspicion for protein-losing enteropathy or lupus serositis; however, confirmatory testing was unavailable. The patient received oral prednisolone at 1 mg/kg/day based on a documented body weight of 50 kg. Within seven days, periorbital edema markedly improved. Serum albumin normalized to 3.8 g/dL by three months. This case illustrates that isolated periorbital edema may be an initial manifestation of systemic lupus erythematosus in adolescents, and the presence of hypoalbuminemia with ascites in the absence of proteinuria should prompt consideration of protein-losing enteropathy or serositis in the differential diagnosis. Early immunological evaluation and corticosteroid therapy were associated with favorable clinical and biochemical outcomes.

Intravascular large B-cell lymphoma (IVLBCL) is a rare extranodal neoplasm in which malignant B cells proliferate predominantly within small blood vessels. Because lymphadenopathy, mass lesions, circulating malignant cells, and specific radiological findings may be absent, IVLBCL can closely mimic other medical conditions, resulting in delayed diagnosis. This case is notable for a prolonged culture-negative sepsis-like presentation with persistent unexplained hypoxemia due to predominant pulmonary microvascular involvement, further obscured by lupus-like autoimmune features and subsequent COVID-19 infection. An older woman in her early 70s presented with fever, lethargy, weight loss, back pain, hypotension, raised inflammatory markers, cytopenia, markedly elevated lactate dehydrogenase (LDH), and progressive hypoxemia. She was initially treated for presumed sepsis, but repeated microbiological investigations and serial imaging did not identify an infectious source, and clinical improvement was not sustained. A transient malar rash and a positive antinuclear antibody raised concern for a lupus-like autoimmune disease; however, testing for anti-double-stranded DNA and extractable nuclear antigen was negative, and the broader autoimmune workup did not support systemic lupus erythematosus as the unifying diagnosis. Subsequent severe acute respiratory syndrome coronavirus 2 infection further complicated the interpretation of hypoxemia and deterioration. Despite antimicrobial therapy, corticosteroids, antiviral treatment, and supportive care, she developed progressive multiorgan failure and died approximately six weeks after admission. Postmortem examination revealed widespread multiorgan IVLBCL involving the lungs, heart, kidneys, liver, spleen, and multiple additional extranodal sites. Pulmonary capillary involvement provided a clinicopathological explanation for persistent unexplained hypoxemia. This case demonstrates how IVLBCL may remain concealed when several plausible diagnoses coexist. Persistent culture-negative fever, constitutional decline, cytopenia, high LDH, nondiagnostic imaging, treatment nonresponse, and unexplained hypoxemia should prompt consideration of IVLBCL and early tissue-based investigation.

Autoimmune myelofibrosis (AIMF) is a rare, potentially reversible cause of bone marrow failure often linked to systemic autoimmune disease. We report a diagnostically challenging case of a 26-year-old woman from sub-Saharan Africa who presented with transfusion-dependent pancytopenia and an initial dry-tap marrow, with further testing limited by financial constraints. Seven months later, evolving clinical and immunologic features-including fever, leukopenia, thrombocytopenia, malar rash, positive ANA, and a sterile exudative pleural effusion-fulfilled the 2019 EULAR/ACR criteria for systemic lupus erythematosus (SLE). AIMF secondary to SLE was subsequently diagnosed, and she demonstrated a rapid hematologic response to glucocorticoids and hydroxychloroquine, remaining transfusion-independent for over five months. This case underscores the diagnostic complexity of AIMF in resource-limited settings and highlights the importance of sustained clinical suspicion and adaptable diagnostic strategies when evaluating unexplained pancytopenia.