Intravascular large B‐cell lymphoma presenting as an indurated subcutaneous plaque
Bibliographic record
Abstract
A 70-year-old woman of Indian descent was referred to dermatology with 7-week history of increasing pain to the lower abdominal skin with concurrent malaise, fever, night sweats and dyspnoea. Prior investigations revealed 7 weeks of progressively worsening normocytic anaemia (haemoglobin 85 g/L from baseline of 115 g/L) and an elevated C-reactive protein (41 mg/L). Investigations showed normal thyroid function, vitamin B12 level, serum and urine protein electrophoresis, esophagoduodenoscopy, colonoscopy and elevated serum ferritin (1152 μg/L). Peripheral smear demonstrated normocytic anaemia with mild thrombocytopenia. Flow cytometry of peripheral blood did not show a lymphoproliferative disorder. Pan-CT imaging revealed a small subpleural right lower lobe nodule and subcutaneous fat stranding in the anterior abdominal wall. Physical examination revealed a tender, indurated erythematous subcutaneous plaque extending across the mid-to-lower pendulous abdomen without epidermal change (Figure 1). Differential diagnosis included lipodermatosclerosis, other panniculitides, deep morphea and subcutaneous panniculitis-like T-cell lymphoma. A deep incisional biopsy was performed, which revealed vessels in the subcutaneous fat filled with large lymphoid cells (Figure 2a). Immunohistochemical stains showed large B-lymphocytes positive for CD20 and CD45, confirming the diagnosis of intravascular large B-cell lymphoma (IVLBCL; Figure 2b). Bone marrow biopsy and MRI of the head and spine were negative for lymphoma involvement. Staging via positron emission tomography showed fluorodeoxyglucose accumulation in the abdominal skin and in several subpleural lung nodules. Intravascular large B-cell lymphoma is a rare subtype of B-cell lymphoma, with an incidence estimated at 1 in 1 million and portends a poor prognosis with an aggressive clinical course. It is a neoplasm of mature B cells, categorized as a distinct entity in the WHO classification of lymphoid neoplasms.1, 2 Histopathology shows the growth of large B cells within the lumen of blood vessels of all sizes, and immunohistochemistry is positive for mature B-cell markers, including CD20, CD79a and PAX5.3 In most cases (90%–95%), lymphoma cells are not found on the peripheral blood smear or flow cytometry of peripheral blood.3 Three clinical variants of the disease have been observed: the classical variant, the cutaneous variant and the haemophagocytic syndrome-associated variant. Clinical manifestations of the classical variant include B symptoms, neurologic symptoms, cutaneous (present in 40% of cases) and visceral involvement. Our patient was consistent with the classical variant given the presence of B symptoms and pulmonary involvement. The cutaneous variant is limited to the skin, is diagnosed in younger patients and has a less aggressive course. The haemophagocytic variant progresses rapidly to systemic illness with bone marrow involvement, fever, hepatosplenomegaly and thrombocytopenia.3 The dermatologic manifestations of the IVLBCL are wide ranging, including indurated erythematous plaques, violaceous or telangiectatic patches, angiomas, ‘peau d'orange’ or ulcerated nodules.3, 4 They commonly present in the submammary region, breast, upper back and thighs. First-line treatment consists of combination immunochemotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) and has a 2–3-year overall survival in 66%–81% of patients.5 The patient was treated successfully with six cycles of R-CHOP. The protean clinical manifestation of IVLBCL makes its diagnosis challenging. We describe a presentation of IVLBCL with a painful abdominal subcutaneous plaque diagnosed via deep biopsy. IVLBCL should be considered in a patient with a localized indurated subcutaneous plaque, B symptoms and progressive anaemia. The patient in this manuscript has given written informed consent to the publication of their case details. The authors have no conflict of interest to report relevant to this study. The data that support the findings of this study are available from the corresponding author upon request.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".