Angioimmunoblastic T-cell lymphoma (AITL) is a rare (2%) and aggressive form of Non-Hodgkin lymphoma, with poor prognosis and median overall survival under 3 years. Most patients with AITL present at an advanced stage (3 or 4). Neuropsychiatric manifestations of lymphoma, though rare, have been reported as associated symptoms. We present a case of successfully treated Stage 2 AITL, whose rare presentation, of florid affective and atypical psychotic phenomena without neurological deficit, eluded clinical detection of AITL for months.

A 58 year-old gentleman with a history of Major Depressive Disorder, presented to hospital with a second episode of generalised tonic clonic seizure, following 4 months of manic disorganised behaviour and multimodal hallucinations.

Atypical psychotic features (preserved insight, multimodal hallucinations resistant to high dose anti-psychotics) and new systemic symptoms prompted suspicion of underlying organic pathology. CT Thorax Abdomen and Pelvis uncovered enlarged bilateral common iliac and external iliac lymph nodes, and small sub-centimetre retroperitoneal nodes. Eventually, Stage 2 Angioimmunoblastic T-cell lymphoma (Pattern 1 & 2), with concomitant psychosis with atypical features, was diagnosed.

Olanzapine 10mg ON and 2.5mg OD PRN, Sodium Valproate EPILIM CHRONO 300mg BD and Diazepam 10mg ON were continued over 6 rounds of chemotherapy and autologous stem cell transplant. The patient remains in remission.

Neuropsychiatric manifestations of lymphoma are rare and usually associated with Central Nervous system (CNS) lymphoma. Here, we observe Stage 2 AITL (without CNS involvement), can present with neuropsychiatric symptoms in the absence of neurological deficits.

We found the combination of Olanzapine, Sodium Valproate and Diazepam to be effective in managing secondary neuropsychiatric symptoms.

Limbic Encephalitis is an important consideration for similar cases despite this patient not meeting the qualifying criteria (unremarkable neuroimaging and EEG).

This case highlights the importance of a thorough history, documenting and understanding the patient's psychopathology (both reported and observed), and differentiating atypical psychotic features which raise suspicions for underlying organic pathology.

This case is an an eye-opener for psychiatric and non-psychiatric clinicians. It reminds us to remain vigilant in such florid psychiatric presentations and highlights the importance of thorough organic workup and psychiatric medications that may be used to successfully address psychosis secondary to lymphoma.

We hope to contribute to the increasing awareness and broadening literature of psychiatric disturbance as initial manifestations of malignant illnesses, and the association between psychiatric manifestations and the rare form of lymphoma, AITL.