Pituitary sarcoidosis

Clinical History

A 19-year-old female patient with a known systemic disease involving the lungs and peripheral lymph nodes presented with the clinical findings of panhypopituitarism developing over the last two months.

Imaging Findings

A 19-year-old female patient with a systemic sarcoidosis involving the lungs and peripheral lymph nodes presented with the clinical findings of panhypopituitarism developing over the last two months. Biochemical evaluation of the patient revealed low serum levels of FSH, LH, TSH, thyroid hormones, estrogen hormones. An MRI study has been performed on a 1.5 T MR scanner, with SE T1, FSE T2, post-gadolinium SE T1 weighted and dynamic images of the pituitary gland on coronal and sagittal planes. Treatment with oral corticosteroids produced a moderate improvement in the hormone levels in 8 weeks. Following the treatment a control MRI study was repeated with the same protocol.

Discussion

Sarcoidosis is a multisystem granulomatous disease, with an unknown etiology. It occurs more commonly in females than in males, it is most commonly seen in between the ages of 20 and 40. The genetically predisposed patients are thought to have an exaggerated cellular immune response to unknown antigens, which leads to noncaseating granuloma formation in sarcoidosis. Sarcoidosis most often involves the lungs, lymph nodes, skin and orbits. Symptomatic central nervous system (CNS) involvement occurs in 5 % of cases, but pathologic CNS involvement is found in up to 25 % of patients at autopsy. The leptomeninges are most often affected, especially the basal cisterns, hypothalamus, optic chiasm and pituitary stalk (infundibulum) in CNS involvement. However any portion of the brain or its appendages may be affected. The diagnosis of sarcoidosis is usually confirmed by histopathological examination, however serum or cerebrospinal fluid angiotensin-converting enzyme (ACE) levels are found to be elevated in approximately 70-80 % of patients with sarcoidosis, hypercalcemia may be found in 2-15 % of the patients due to enhanced sensitivity to vitamin D. The diagnosis of neurosarcoidosis is often difficult, particularly so in patients who lack either pulmonary or systemic manifestations of sarcoidosis. In selected cases with isolated brain involvement, meningeal or cerebral biopsy may be required. Histological examination shows noncaseating granulomata that contain macrophages, epithelioid cells, and multinucleated giant cells. MRI shows a wide range of central nervous abnormalities: hypotalamic-pituitary infiltrating lesions; cerebral parenchymal masses; leptomeningeal lesions; and focal white-matter lesions. On MRI, the lesions are usually isointense to hypointense with cortical gray matter on T1-weighted images, and are variable on T2-weighted images, but often hypointense to gray matter, with marked contrast enhancement following IV gadolinium administration. The patients with sarcoidosis may rarely present with sellar masses, with the signal characteristics described herein, and marked contrast enhancement. Pituitary adenomas, lymphocytic hypophysitis, idiopathic giant cell hypophysitis, other granulomatous hypophysitis conditions, and meningioma of the diaphragma sellae should be considered in the differential diagnosis of such cases. The choice of treatment is the use of corticosteroids, however alternative treatment (including methotrexate, cyclophosphamide, azathioprin, cyclosporin) can be used in resistant cases.

Differential Diagnosis List

Final Diagnosis

Pituitary sarcoidosis

URL:	https://eurorad.org/case/1069
DOI:	10.1594/EURORAD/CASE.1069
ISSN:	1563-4086