Delayed diagnosis of Angioimmunoblast T-cell lymphoma presenting with type II Cryoglobulinemia and acute kidney injury: a case report and narrative review of the literature

BACKGROUND: Angioimmunoblastic T cell lymphoma (AITL) is an infrequent hematological malignancy with variable and often atypical presentations. The presence of dysproteinemia, autoantibodies and systemic involvement in AITL has often led to a delay in diagnosis or even misdiagnosis in practice. We herewith present a case of AITL that primarily presented with acute kidney injury associated with type II Cryoglobulinemia, the underlying cause was only identified 8 months after the emergence of initial symptoms. CASE PRESENTATION: A 67-year old woman presented with 2-month history of intermittent joint pain and a 3-day history of bilateral lower limb edema and acute kidney injury. Initial laboratory investigations showed marked hypocomplementemia with positive autoantibodies of ANA, anti-cardiolipin-IgM and direct antiglobulin. The serum and urinary Immunofixation and serum cryoglobulin tests were negative, while the serum free κ to λ light chain ratio was 0.231. A renal biopsy showed a diffuse proliferative glomerulonephritis with intracapillary pseudothrombi formation. There were orderly arranged microtubular structures of 20–35 nm in diameter in the subendothelial and mesangial area on electron microscopy. Shortly afterwards, the patient developed tingling affecting her finger tips and weak hands and legs. A diagnosis of cryoglobulinemia complicated with cryoglobulinemic glomerulonephritis and polyneuropathy was made. She responded well to methylprednisolone, plasma exchange and rituximab. However, 3 months later, she presented with generalized pruritic rash, weight loss, and inguinal lymphadenopathy. A subsequent inguinal excisional lymph node biopsy at month 8 revealed AITL as the underlying disease. CONCLUSIONS: AITL and its associated B cell dysregulation can give rise to autoimmunity and cryoglobulinemia which may conceal itself as the underlying disorder. In various clinical scenarios of auto-immune diseases, it is advisable that the clinicians should take into consideration the multi-faceted lymphoma.