Severe type-B lactic acidosis in a patient with bilateral renal Burkitt's lymphoma

Abstract

Introduction: Lactic acidosis (LA) can be categorized as type A, which occurs in the presence of tissue hypoxia, or type B, occurring in the absence of tissue hypoxia. Hematologic malignancies are an uncommon cause of type B LA.

Case presentation: A 63-year-old man, HIV-negative, with a history of diabetes mellitus, hypothyroidism, and non-alcoholic fatty liver disease (NAFLD), presented to the ED complaining of acute-on-chronic lumbar pain, and was found to have high serum anion gap (AG) LA. The rest of chemistry and infectious workup was within normal limits. Despite bicarbonate therapy and fluid resuscitation, the patient remained with persistent AG metabolic acidosis and increasing lactic acid up to 14.5 mmol/L. An abdominal computerized tomography (CT) revealed multiple bilateral enhancing lesions in the kidneys, as well as gastric wall thickening. Upper gastrointestinal endoscopy with biopsy showed a high-grade Burkitt's lymphoma. Further staging showed bone marrow involvement and extensive abdominal adenopathy. After two cycles of inpatient chemotherapy with dose-adjusted EPOCH-R (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin and rituximab), the patient developed multifocal pneumonia complicated by respiratory failure. Following a prolonged ICU stay, after discussion with the family members, a decision of withdrawal of life-sustaining therapy was reached.

Conclusion: Persistent LA, without identifiable causes of tissue hypoxia, should prompt clinicians to suspect non-hypoxic etiologies, including occult high-grade malignancies. Hematological malignancies constitute an extremely rare cause of type-B LA, carrying a poor prognosis.

Keywords: Burkitt’s lymphoma; kidney neoplasms; lactic acidosis; non-Hodgkin lymphoma.

Figure 1. Abdominal CT scan with contrast. Findings of bilateral enhancing lesions in the kidneys. Multiple rounded hyperdense lesions throughout the renal parenchyma bilaterally, more pronounced in the left kidney. Left perinephric hematoma 8.8 × 5.2 cm. Axial view (left). Diffuse thickening of the stomach wall. No evidence of liver lesions. Axial view (right).

Figure 2. Abdominal MRI. Multiple rounded hypo enhancing lesions noted throughout the renal parenchyma bilaterally. Axial view (left). Coronal view (right).

Figure 3. Microscopic appearance of the high-grade Burkitt’s lymphoma. Stomach. Gastric mucosa with a dense lymphoid infiltrate in the lamina propria consisting of intermediate size monotonous lymphoma cells with round nuclei, fine chromatin, and multiple nucleoli. Mitoses are conspicuous. Multiple apoptotic bodies impart a starry sky pattern to the lesion (A, B: hematoxylin & eosin). Immunohistochemistry was positive for CD20, CD10, BCL6 (C), c-MYC (D), and MUM1, and are negative for CD5, BCL2, CD30, and terminal deoxynucleotidyl transferase (TdT). Fluorescence in situ hybridization (FISH) was 73% positive for MYC-IGH fusion and negative for IGH-BCL2 and BCL6 rearrangements.