Innumerable hemorrhagic brain metastases from a neuroendocrine tumor grade-1 with prolonged natural history

Neuroendocrine tumors (NET) are rare tumors with a low incidence of brain metastasis, especially in grade 1 NET. The most common source of brain metastasis is the lung. We present an unusual case of NET grade 1 with multiple hemorrhagic brain metastases.

A 46-year-old woman, who initially presented with a seizure, was diagnosed with multiple brain and lung lesions. She was offered a biopsy for diagnosis, but she refused and lost to follow up. Eighteen years later, she developed progressive quadriparesis and confusion. A biopsy of the left frontal lobe lesions showed NET grade 1. A lung biopsy of the left upper lobe was consistent with the same diagnosis. The patient's functional status was poor with Eastern Cooperative Oncology Group (ECOG) grade 4. She only received palliative whole-brain radiation therapy (WBRT) and died 3 months after discharge.

NET is a spectrum that encompasses benign to malignant cells. There is a female predominance in lower grades and male predominance in higher grades. No effective management for brain metastases was described, and the prognosis remains poor.

Multiple brain metastases can be the first presentation of patients with NET. Early diagnosis and treatment may have a more favorable impact on the outcome of this disease. The longstanding numerous hemorrhagic NET brain metastases is exceedingly rare. The neuroimaging appearance is similar to other neoplastic and non-neoplastic lesions. An important differential diagnosis to consider is metastatic melanoma and choriocarcinoma, familial cavernous malformation, diffuse axonal injury, cerebral vasculitis, and amyloid angiopathy.