Hematologic Malignancies: Two Cases of a Rare Cause of Hypopituitarism

Hematologic malignancies are rare causes of sellar masses and hypopituitarism. We report 2 cases of hypopituitarism due to sellar masses from hematologic malignancies. The first patient was found to have hypopituitarism but initial non-gadolinium-enhanced magnetic resonance imaging (MRI) sella did not demonstrate a mass. Subsequent gadolinium-enhanced MRI and transsphenoidal biopsy confirmed a diagnosis of intravascular lymphoma. Treatment with systemic chemotherapy resulted in resolution of abnormalities on MRI. The second patient had a known diagnosis of chronic lymphocytic leukemia, and sellar involvement contributing to hypopituitarism was confirmed on biopsy. Treatment with ibrutinib, acalabrutinib, and stereotactic radiosurgery resulted in resolution of abnormalities on MRI. Both patients were treated with hormone replacement for hypopituitarism. These cases highlight that hematologic malignancies should be suspected as causes of sellar masses/hypopituitarism in patients with concurrent symptoms atypical for a pituitary adenoma (eg, constitutional symptoms), known diagnoses of hematologic malignancies, or rapid tumor growth and invasion on imaging. Gadolinium-enhanced MRI should be pursued if nonenhanced MRI is nondiagnostic. Transsphenoidal biopsy can be considered for diagnosis. Malignancy-directed systemic therapy may improve hypopituitarism and radiographic abnormalities on MRI.