A Rare Case of Pituitary Metastasis from Esophageal Adenocarcinoma

Introduction:
Metastases to the pituitary gland are uncommon. Metastatic lesions represent <1% of sellar masses ⁽¹⁾. Breast and lungs are the most common primary tumors associated with pituitary metastasis, representing nearly 60% of cases ⁽¹⁾. Esophageal adenocarcinoma is a very rare cause of pituitary metastasis and only a few cases have been reported. We present a very rare case of a patient with pituitary metastasis from esophageal adenocarcinoma.

Case Description:
49-year-old male presented with a 2-month history of progressive fatigue, chills, lightheadedness, poor appetite, headaches, and decreased peripheral vision. One month before admission he was diagnosed with an invasive moderately differentiated esophageal adenocarcinoma. Head CT showed a heterogeneous hyperdense pituitary mass. Pituitary MRI confirmed a 2.13 x 0.9 cm heterogeneously enhancing, lobulated sellar mass with suprasellar extension and at least 2 sub-centimeters areas of enhancement within the right frontal lobe. CT chest, abdomen, and pelvis with splenomegaly, multiple lesions in the lungs, liver, and bilateral adrenal glands, concerning for metastases.

Laboratories showed a cortisol level of 1.2 mcg/dL, TSH 1.074 (0.46-4.7 uIU/mL), free T4 <0.42 (0.7-1.30 ng/dL). Prolactin 3.9 (2.5-17.0 ng/mL), LH <0.1 (0.8-7.6 mIU/mL), FSH 0.9 (0.7-11.1 mIU/mL), total testosterone <4.33 (240-871 ng/dL), and IGF-1 76 (53.3-215 ng/mL). No evidence of diabetes insipidus. The patient was started on levothyroxine 150 mcg daily and hydrocortisone 15 mg in the morning and 5 mg in the afternoon.

Ophthalmologic evaluation showed multiple elevated retinal lesions in both eyes, concerning for metastatic implants. No acute intervention per neurosurgery. After discharge, an adrenal biopsy confirmed metastatic esophageal adenocarcinoma. The patient underwent whole brain radiotherapy (WBRT) and was started on FOLFOX, trastuzumab, pembrolizumab, and zometa. MRI 3 months later showed decrease in size of enhancing lesion most suspicious for metastasis within the right frontal lobe and sella turcica.

Discussion:
Pituitary metastases are usually diagnosed in the 6^th and 7^th decade of life with widespread metastatic disease. Esophageal adenocarcinoma is a rare cause of pituitary metastasis with few cases reported. Patients may be asymptomatic, but others may present with diabetes insipidus, visual disturbances, headaches, and panhypopituitarism ⁽²⁾. Our patient presented at a younger age with symptoms indicative of pituitary failure. Although these may be nonspecific, it is important to maintain awareness of them so that testing and treatment can be performed in a timely fashion.