IGH, a rare inflammatory disease of the pituitary gland, is a diagnosis of exclusion for which both medical and surgical management are reported in the literature. We described a case of IGH presenting with galactorrhea, headaches, and nausea who did not respond to medical treatment and underwent transsphenoidal resection. She was symptom free with no complication of hypopituitarism after 9 months of follow-up.
Inflammation of the pituitary gland can occur as a primary phenomenon or secondary to various systemic diseases. The diagnosis of primary hypophysitis is made following exclusion of secondary causes and can be subdivided based on histologic findings into five different subtypes: lymphocytic, granulomatous, xanthomatous, xanthogranulomatous, and necrotizing . IGH is second to lymphocytic hypophysitis in prevalence. Secondary causes of granulomatous hypophysitis include tuberculosis, sarcoidosis, syphilis, pituitary adenoma, Langerhans cell histiocytosis, Wegener’s granulomatosis, and Rathke’s cleft cyst rupture .
The majority of cases of IGH become clinically apparent with headaches, nausea, and visual and oculomotor disturbances due to mass effects from an enlarged pituitary gland, prompting the need for surgical resection of the gland. It follows, therefore, that a large number of cases of IGH may be subclinical or manifest in ways that are not attributable to mass effects. The most clinically significant manifestations are central diabetes insipidus (DI) and hypopituitarism. IGH may account for a portion of cases of hypopituitarism and central DI for which treatment is issued without knowing the cause . The symptoms in our case were attributed to the enlargement of the pituitary gland, causing a modestly high level of serum prolactin secondary to stalk compression.
Different studies have reported different rates of endocrine abnormalities in primary hypophysitis. In a review of 22 cases by Park et al., infundibuloneurohypophysitis was the most common subtype, either isolated or combined with anterior hypophysitis, with 18 out of the 22 reviewed cases (82%) suffering from DI . Hunn et al. reviewed 82 cases among whom suppression of hypothalamus–pituitary–adrenal axis was the most common (73%) while DI rate was reported as 27% . Increased prolactin levels were found in 23% and 52% of the cases reviewed in these studies respectively [1, 2]. In a review of 379 cases of primary lymphocytic hypophysitis, anterior pituitary hormones were deficient in 90% of cases while 35% developed DI. There is still some debate concerning whether lymphocytic and granulomatous hypophysitis are different clinical entities or temporarily distinct parts of the same disease process in the course of which lymphocyte-dominant inflammation occurs earlier and granulomatous changes appear later .
Granulomatous hypophysitis closely mimics a pituitary adenoma clinicoradiologically. Most of the time, a diagnosis is only reached after histopathological studies. Most cases described so far have therefore been diagnosed after surgery. It has been postulated, however, that if one suspects hypophysitis before surgery, improvement following steroid therapy may help in differentiating the two . A thickened stalk on MRI has been cited as the most characteristic radiology finding in favor of hypophysitis .
Current literature suggests that suspected inflammatory lesions of the pituitary should be managed conservatively and surgery should be performed only in the presence of serious and progressive deficits of visual fields, visual acuity, or ocular movements that are not responsive to medical treatment . There have been several reports of satisfactory response to steroid and immunosuppressive treatments . Xu et al. posited that pure glucocorticoid treatment is probably less effective in granulomatous hypophysitis than in lymphocytic hypophysitis and recommended it only as an adjuvant to minimally invasive surgery . Hunn et al. reviewed 82 cases of IGH . Among 64 cases for whom data on treatment modalities were available, the majority were treated with excisional pituitary surgery alone (46.9%, n = 30/64), excisional surgery and corticosteroids (35.9%, n = 23/64), or pituitary biopsy and corticosteroids (14.1%, n = 9/64). The authors did not find statistically significant differences in needs for hormone replacement therapy or recurrence rates between different treatment modalities .
Normal pituitary tissue is usually preserved at the hands of experienced pituitary neurosurgeons and the need for long-term hormonal replacement is predicted by panhypopituitarism at presentation. If there is concern that complete removal of the mass may compromise an otherwise preserved pituitary function, it is reasonable to diagnose hypophysitis with transsphenoidal biopsy and fast frozen pathology, since the condition is amenable to corticosteroid therapy . Galactorrhea, hyperprolactinemia, normal gonadal axis, and euthyroidism at presentation have all been associated with reduced requirement for long-term hormone replacement . Stereotactic radiotherapy as reported by Selch et al. has been successfully employed in the treatment of recurrent lymphocytic hypophysitis  and it can be considered a potential noninvasive treatment of granulomatous hypophysitis especially in cases of disease recurrence or resistance to glucocorticoids.