Review of xanthomatous lesions of the sella

Abstract

Xanthomatous lesions of the sellar region have traditionally been divided into two separate categories, xanthomatous hypophysitis (XH) and xanthogranuloma (XG) of the sellar region. The seminal article on XH, a condition typified by foamy histiocytes and lymphoplasmacytic infiltrates in the pituitary gland/sellar region, but usually little or no hemosiderin pigment, detailed three patients. However, most reports since that time have been single cases, making understanding of the entity difficult. In contrast, the seminal report on XG, characterized by sellar region cholesterol clefts, lymphoplasmacytic infiltrates, marked hemosiderin deposits, fibrosis, multinucleated giant cells around cholesterol clefts, eosinophilic granular necrotic debris, and accumulation of macrophages, included 37 patients, allowing more insights into etiology. Few examples could be linked to adamantinomatous craniopharyngioma, and although ciliated epithelium similar to that of Rathke cleft cyst (RCC) was identified up to 35% of the 37 cases, it could not be proven that XG was related to hemorrhage into RCC. Case reports since that time, however, occasionally linked XG to RCC when an etiology could be identified at all, and a few recognized that a spectrum exists in xanthomatous lesions of the sella. They review literature, adding 23 cases from our own experience, to confirm that overlap occurs between XH and XG, and that the majority-but not all-can be linked to RCC leakage/rupture/hemorrhage. It was suggested that progressive accumulation of hemosiderin pigment in the lesion, possibly caused by the multiple episodes of bleeding, could account for the transition of at least some cases of XH to XG.

Functioning Pituitary Adenoma with Xanthogranulomatous Features: Review of Literature and Case Report

“…In 1999, Paulus et al described them as a separate entity from craniopharyngiomas with subsequent reports of them being associated with hemorrhage or rupture of Rathke's cleft. 1,2 Sellar XGs can be easily mistaken for craniopharyngioma, which significantly impacts the management strategy including the selection of the surgical approach and outcome prediction.…”

“…5 As described by Kleinschmidt-DeMasters et al 2 and Burt et al, 18 xanthomatous lesions of the sella which include XH, XGH, and XG have been hypothesized to represent a continuum or spectrum. 2,18 In the series of 23 cases from our joint adult and pediatric hospitals, Kleinschmidt-DeMasters et al identified 10 sellar XG cases associated with epithelium from RCC, 5 XG cases associated with scant epithelium with or without associated mucin and thus no definitive underlying cause, and 5 with no underlying epithelium, tumor or causation for the sellar XG. Only two were related to adamantinomatous craniopharyngioma, one to epidermoid cyst and one to pituitary adenoma, the current case which is detailed in the current report.…”

“…Only two were related to adamantinomatous craniopharyngioma, one to epidermoid cyst and one to pituitary adenoma, the current case which is detailed in the current report. 2 Thus, while an underlying RCC is found in a significant subset of XGs of the sella, the etiology and pathogenesis of many examples of this entity remain unclear. The granulomatous entity might occur secondary to inflammation, hemorrhage, infarction, or necrosis.…”

“…The origin of XG is unclear in some cases, although reports since Paulus et al have usually identified remnants of Rathke's cleft cyst (RCC), often with remote hemorrhage, as a predecessor for a significant subset of these lesions. 2,3 Few reports describe an association with adamantinomatous craniopharyngiomas or pituitary adenomas, 2,4 and even fewer describe prolactinomas with xanthogranulomatous features.…”

The Significance of Extracellular Cholesterol Crystals or a Cholesterol Granuloma in Xanthelasma

“…In other nonophthalmic sites and tissues where cholesterol granulomas develop, there has been no relationship established with respect to abnormalities in serum lipids [32-36]. Examples include a leaking craniopharyngioma or Rathke’s pouch cyst, skin cysts, inflammation of the petrous bone apex, and involvement of the hypophysis, mediastinum, kidney, breast, parotid, testis, liver, spleen, and peritoneum [32, 33, 35]. On the other hand, uninflamed cholesterol crystalloids are highly suggestive of an accompanying serum hyperlipidemia (Table 1) and should prompt a thorough serum lipid profile and apolipoprotein analysis.…”