Giant anterior communicating artery aneurysm infiltrated with a primary cerebral lymphoma: Case report

OBJECTIVE AND IMPORTANCE: Central nervous system lymphomas exhibit angiotropic characteristics. Nevertheless, direct association with an intracranial aneurysm is very rarely reported. We present a case of a giant aneurysm infiltrated with a large cell non-Hodgkin's lymphoma. The incidence of primary central nervous system lymphoma is increasing, and similar cases may become more frequent in the future. CLINICAL PRESENTATION: A 65-year-old man had presented with a giant anterior cerebral artery aneurysm, new onset of seizures, aphasia, and hemiparesis. The aneurysm was treated with Guglielmi detachable coils. Six months later, the patient exhibited fever and neurological deterioration. Magnetic resonance images suggested an enhancing lesion posterior to the neck of the aneurysm. Antibiotic treatment given elsewhere was unsuccessful. INTERVENTION: A craniotomy for a suspected abscess was performed, with removal of the aneurysm and clipping of the neck. The aneurysm sac appeared to be filled with thrombus and pus. The results of aerobic, anaerobic, and fungal cultures were negative. Postoperative magnetic resonance images demonstrated a residual mass, posterior to the aneurysm within the striatum and the internal capsule. Histological examination of the aneurysm wall revealed a large B-cell lymphoma. The diagnosis was confirmed by a stereotactic biopsy. Radiation therapy resulted in a transient decrease in the size of the lesion. CONCLUSION: Although the tumor was not apparent on the initial imaging studies, it may have been the cause of the patient's presenting symptoms. Infiltration of the aneurysm wall by the lymphoma also raises the possibility of a causal relationship. As the incidence of primary central nervous system lymphoma is reported to be on the increase, awareness this uncommon association of an aneurysm and malignant lymphoma is of value.