Table 1

Evaluation and exclusion of differential diagnoses

Differential diagnosis	Features in favour	How diagnosis was excluded
Lymphoma	CSF findings of lymphocytosis with raised protein Widespread lymphadenopathy on CT of the chest, abdomen and pelvis Peripheral lymphopaenia since the onset of symptoms ranging between 0.5×10⁹/L and 1.0×10⁹/L (NR: 1.4–4.8×10⁹/L) Maternal history of breast cancer	Absence of atypical cells on CSF flow cytometry No evidence of lymphoma on tissue biopsy
Chronic pathogenic infections	Subacute history with neurological symptoms Lymph node biopsy showing granulomatous lymphadenitis CSF showing raised lymphocytes, low glucose and raised protein suggestive of tuberculosis or fungal infection	Negative CSF, serum, urine and sputum analysis for pathogens, including acid-fast bacillus stains, prolonged culture and mycobacterium tuberculosis PCR on CSF Negative staining for microorganisms on lymph node biopsy
Carcinomatous meningitis	Subacute history with neurological symptoms and aseptic meningitis	Absence of malignancy identified on CT of the chest, abdomen and pelvis/MRI of the brain and spine No malignant cells in CSF
Autoimmune vasculitis	Lymph node biopsy showing granulomatous lymphadenitis	Negative auto-antibody screen
Phaeochromocytoma	Headache and visual disturbances Labile blood pressures ranging between 191/114 mm Hg and 220/142 mm Hg	Normal 24-hour urinary metanephrines Absence of adrenal mass on CT of the chest, abdomen and pelvis