Pulmonary atypical carcinoid tumor with metastatic involvement of the pituitary gland causing functional hypopituitarism.

OBJECTIVE

To report a unique case of a peripherally located pulmonary atypical carcinoid tumor with metastatic involvement of the pituitary, manifesting with evidence of functional hypopituitarism and compressive symptoms of dysarthria, bitemporal loss of vision, and ataxia.

METHODS

We present a case report, including detailed laboratory, radiologic, and pathologic findings in a 50-year-old woman with a peripherally located pulmonary atypical carcinoid tumor and a lesion metastatic to the pituitary gland. The pertinent literature is also reviewed.

RESULTS

A 50-year-old woman with a medical history of metastatic pulmonary atypical carcinoid tumor presented with symptoms of bitemporal hemianopia, ataxia, and dysarthria. Laboratory evaluation revealed functional hypopituitarism, and magnetic resonance imaging of the brain with use of gadolinium contrast demonstrated a pituitary lesion measuring 3.5 by 2.5 by 2.5 cm. Visual field testing revealed bitemporal superior quadrantanopia, consistent with a pituitary lesion of the chiasm. Computed tomographic angiography excluded the presence of an aneurysm of the internal carotid artery. Subsequently, the patient underwent subtotal transsphenoidal hypophysectomy. Findings on pathology examination were consistent with a lesion metastatic from the primary pulmonary atypical carcinoid tumor. The patient subsequently received monthly octreotide injections as well as chemotherapeutic regimens of capecitobine and temozolomide. At 18-month follow-up, disease had not recurred.

CONCLUSION

This case of metastatic involvement of the pituitary gland from a peripherally located pulmonary atypical carcinoid tumor manifesting with evidence of functional hypopituitarism is highly uncommon. To our knowledge, such a case has not been previously reported. The presentation of an advanced pituitary metastatic lesion can be particularly dramatic, and the course can be potentially complicated. Therefore, heightened awareness of the possibility of a pituitary lesion metastatic from a pulmonary atypical carcinoid tumor is important.