Metastatic Lung Cancer Presenting as Monocular Blindness and Panhypopituitarism Secondary to a Pituitary Metastasis

Abstract

BACKGROUND Sellar masses are most commonly pituitary adenomas, however, about 1% of surgical resected pituitary lesions are found to be metastatic disease. It is hard to distinguish pituitary adenomas from metastatic disease. The most common primary sources for pituitary metastases are breast and lung cancer. CASE REPORT In this paper, we report the case of a woman who presented with right-sided vision loss who was found to have a sellar mass and panhypopituitarism. Subsequent imaging showed a large mass in her left upper lung with additional lesions in the spleen and adrenal glands. Neurosurgery performed an urgent transsphenoidal resection, with pathology confirming lung adenocarcinoma. CONCLUSIONS This is an unusual presentation of metastatic lung cancer, with the patient's primary symptoms being related to her pituitary metastasis and panhypopituitarism. Pituitary metastases are most commonly asymptomatic, although they can present with visual disturbances, diabetes insipidus, or panhypopituitarism. Pituitary metastases should be on the differential for sellar masses, particularly with specific radiographic findings, visual disturbances, and/or the presence of diabetes insipidus.

Figure 1.

(A) Axial and (B) coronal magnetic resonance imaging showing “expansile sellar and suprasellar mass which measures 22×20×19 mm” (arrows).

Figure 2.

Computed tomography chest with contrast that highlights the 5.3×4.0 cm left upper lobe mass (arrow) that “abuts and may invade the left mediastinum”.

Figure 3.

(A, B) Histology shows gland-forming carcinoma cells (lower left) invading normal anterior pituitary tissue (upper right). Mitoses are apparent at higher power (arrows in B). Tumor cells are positive for CK7 (C) and TTF-1 (D), consistent with adenocarcinoma of lung origin.