Isolated pineal region metastasis from lung adenocarcinoma with obstructive hydrocephalus: a case report

INTRODUCTION Although the brain is a common site of metastasis from lung cancer, pineal region metastasis from lung adenocarcinoma is rare. Most cases of pineal metastases are asymptomatic, and are diagnosed by autopsy. Therefore, the management of pineal region tumors remains controversial. Here, we present a rare case of lung carcinoma presenting with pineal region metastasis and obstructive hydrocephalus as the first manifestation of the lung adenocarcinoma. CASE PRESENTATION A 63-year-old Japanese woman was referred to our hospital for treatment of a tumor of the pineal region associated with hydrocephalus. On admission, she was found to have a mass in her right lung on a chest radiograph. During the preoperative investigation, the patient began to show a progressively worsening level of altered consciousness. Therefore, neuroendoscopic surgery was performed as an emergency procedure, which resulted in improvement of the hydrocephalus and diagnosis of adenocarcinoma. A systematic investigation revealed adenocarcinoma of her right lung as the primary lesion. She was treated by a platinum-based chemotherapy regime. Stereotactic radiation to the pineal region was undertaken concurrently. After completion of the chemotherapy, the primary lesion and pineal region metastasis showed good partial response. CONCLUSION The prognosis of pineal region metastasis is extremely poor, and only three patients with metastatic pineal region metastasis from lung cancer who were treated by chemotherapy have been reported. We performed neuroendoscopic surgery to obtain resolution of the obstructive hydrocephalus and the definite histological diagnosis. This resulted in improvement of the general condition of the patient, and the patient could be treated by chemotherapy and radiotherapy. We strongly believe that neuroendoscopic surgery was a good option in this case. This case report suggests that in the presence of an isolated pineal region tumor, metastasis should be considered a possible diagnosis, and careful examination for systemic malignant disease will be needed.