Xanthogranuloma of the Sellar Region: A Comprehensive Review of Neuroimaging in a Rare Inflammatory Entity

Rathke's cleft cyst: From history to molecular genetics

A Rathke's cleft cyst (RCC) is a remnant of the embryologic Rathke's pouch and a common pituitary lesion. A true RCC is lined with ciliated cuboidal or columnar epithelia with occasional goblet cells and squamous metaplasia. A RCC is frequently diagnosed incidentally through magnetic resonance imaging and computed tomography of the brain or pituitary gland. Presentation can range from an asymptomatic clinical picture to a rapidly progressive disease. RCC are located most often in the sellar and suprasellar regions and a careful differential diagnosis is crucial, especially to exclude craniophryngioma. Recent studies illuminate novel molecular mechanisms and markers for understanding the pathogenesis of RCC. PROP-1, a paired-like homeodomain transcription factor, controls pituitary ontogeny and its high expression induces RCCs. Both transgenic mouse models and immunohistochemical analysis of human RCCs indicate that the leukemia inhibitory factor is involved in pathogenesis. The expression of cytokeratins 8 and 2 in RCCs, but not in craniopharyngiomas, and the presence of beta-catenin mutations in many craniopharyngiomas, but not in RCCs, help with the differential diagnosis. For asymptomatic and small RCCs, observation is appropriate, with serial magnetic resonance imaging and hormonal investigation depending on the patient's clinical status. Surgical resection may be required for symptomatic RCC and recurrence rates are generally low. For patients with a recurrence, stereotactic radiosurgery is an effective approach with low risk.

Endoscopic Endonasal Approach for Calcified Sellar/Parasellar Region Pathologies: Report of 11 Pituitary Adenoma Cases

OBJECTIVE

Calcification in pituitary adenomas is a rare occurrence and its differential diagnosis typically includes other sellar masses. Common calcifications in pituitary adenomas are classified into 2 morphological forms: capsular (eggshell-like) and multiple small nodular calcifications located within the adenoma. Also, there is a pituitary stone term. This study aims to present the results of calcified pituitary adenoma case series who underwent endoscopic endonasal approach (EEA) and the clinical, histopathological characteristics and surgical outcomes of these cases.

METHODS

This study conducted a retrospective cohort analysis of patients with calcified pituitary adenoma operated on by EEA between August 1997 and February 2024. The inclusion criteria were as follows: proven radiological calcification on preoperative neuroimaging, intraoperative findings of calcification, and definitive histopathological diagnosis of calcification. Among these patients, 11 cases were included.

RESULTS

The mean follow-up duration was 51.45 ± 37.24 (6-118) months. Based on the preoperative paranasal sinus computed tomography scans of patients, 9 patients (81.8%) had intratumoral calcification, 1 (9.1%) had capsular (eggshell-like) calcification, and 1 (9.1%) had both intratumoral and capsular calcification. Moreover, stone-like calcifications were observed in 4 patients (36.4%), soft-type calcifications in 3 (27.3%), hard-type calcifications in 3 (27.3%), and soft-type and hard-type calcifications in 1 (9%). Gross total resection was achieved in 9 patients (81.8%). Pathologic subtypes included nonfunctioning (n = 4), prolactin secreting (n = 3), growth hormone-secreting adenoma (n = 2), and pituitary apoplexy (n = 2). Ten patients had psammomatous-type calcifications and 1 had extensive ossification and osteoid metaplasia.

CONCLUSIONS

Preoperative radiological evaluation, intraoperative classification of calcification, and postoperative histopathological assessments are crucial in the treatment of calcified adenomas. Bases on these findings, the EEA, with its advantages, is an approach that can be effectively used in the management of these calcified adenomas.

Intrasellar xanthogranuloma mimicking macroadenoma

Intracranial xanthogranulomas (XGs) have been found at various sites, but xanthogranuloma of the sellar region is extremely rare. We report about a case of sellar XG in a 34-year-old female. Magnetic resonance imaging showed a solid-cystic mass located at the sella turcica. The cystic component was hyperintense on the T1-weighted image (WI) and T2WI. The solid component was hyperintense on T1WI and hypointense on T2WI. There was peripheral enhancement after gadolinium administration. The diagnosis of cystic macroadenoma was considered before surgery. Final diagnosis of XG was confirmed by histopathological examination after surgical resection. Gross total resection of the lesion was achieved using the microscope through endoscopic endonasal transsphenoidal approach. The patient had a good outcome and no symptom of diabetes insipidus, hormonal evaluation did not show any alterations compatible with hypopituitarism and prolactin levels were normal XG should receive diagnostic consideration for the sellar mass lesions with cystic components hyperintense on T1WI and T2WI, solid components hyperintense on T1WI and hypointense on T2WI, and CT without evidence of calcifications. It is important to consider the possibility of XG when pertinent, as it facilitates a proper surgical approach strategy.

Calcified Pituitary Adenoma Mimicking Craniopharyngioma: A Case Report

A 60-year-old woman presented with a history of a previously diagnosed sellar mass and a recent onset of severe headache, vision loss, and dizziness. The patient was found to have a large mass with curvilinear calcification on imaging. Histopathology confirmed the presence of a pituitary adenoma with abnormal acini, consistent with adenoma, and moderate amounts of granular eosinophilic cytoplasm. A detailed analysis of the patterns of calcification and the radiological morphology is crucial to distinguishing between pituitary adenoma and craniopharyngioma. Recognition of these patterns can aid in distinguishing between these conditions, providing a more accurate diagnosis and an effective treatment plan.

Sellar Xanthogranulomatosis in a Two-Year-Old Girl: A Case Report

Sellar xanthogranulomas are extremely rare intracranial lesions, particularly in pediatric patients, and their diagnostic and therapeutic challenges prompt thorough investigation. We describe a case of a two-year-old toddler diagnosed with sellar xanthogranuloma, highlighting the challenges encountered in its diagnosis and management. The child presented with symptoms, including headache, ptosis of the left eye, and neurological deficits. Brain computed tomography (CT) and magnetic resonance imaging (MRI) revealed a hypodense sellar lesion. The patient underwent a left pterional craniotomy for resection of the mass. Histopathological examination suggested the diagnosis of sellar xanthogranuloma, characterized by foamy macrophages, giant cells, lymphocytic infiltrates, fibrous proliferation, necrotic detritus, and hemosiderin deposits. Further diagnostic precision was achieved through immunohistochemical staining, including CD1a and langerin, which successfully ruled out the possibility of Langerhans cell histiocytosis (LCH), reinforcing the diagnosis of sellar xanthogranuloma. The successful surgical resection of the lesion led to a favorable outcome, evidenced by the significant alleviation of symptoms as well as the restoration of normal neurological function. Post-operative assessments demonstrated a marked improvement in the patient's quality of life, and there were no observed complications or recurrence of the lesion during the follow-up period. In summary, our case report not only highlights the rarity and diagnostic challenges of sellar xanthogranulomas but also emphasizes the importance of collaborative medical expertise in achieving accurate diagnosis and successful therapeutic outcomes in pediatric patients. The successful management of this case offers valuable insights into the clinical presentation, diagnostic complexities, and treatment strategy of sellar xanthogranulomas, further enriching our understanding of this uncommon intracranial pathology.

Sellar xanthogranuloma as a diagnostic challenge: a report on five cases

Xanthogranulomas are considered rare tumors, with their sellar and non-sellar frequency ranging from 1.6 to 7% among intracranial lesions, and described as a separate entity by the World Health Organization in 2000. The diagnosis of sellar xanthogranulomas is challenging, given their uncertain origin and clinical course. In addition, the limited reporting of sellar xanthogranuloma cases and the absence of characteristic images make these entities difficult to distinguish from other cystic lesions of the sellar region, such as adamantinomatous craniopharyngiomas, Rathke's cleft cysts, pituitary tumors, arachnoid cysts, epidermoid cysts, and dermoid cysts. Here, we describe the clinical presentation, radiological findings, immunohistochemical/histopathological analysis, and the ultrastructural examination by transmission electron microscopy of five sellar xanthogranulomas cases reported in two care centers in Cordoba, Argentina. Two males and three females between 37 and 73 years of age (average 51.8 years) presented with persistent headaches, generalized endocrine defects, and visual problems. MRI revealed cystic formations in the sellar region, which usually projected into adjacent tissues such as the suprasellar region or cavernous sinuses, and compressed other structures such as the optic chiasm, pituitary gland, and cranial nerves. All patients underwent surgical intervention to remove the tumor tissue. The histopathological analysis of the samples showed cellular tissue with a xanthogranulomatous appearance, inflammatory cellular infiltrate (mainly lymphocytes and macrophages), fibroblasts, abundant collagen fibers, and hemorrhages. An ultrastructural analysis helped to identify cellular infiltrates and granules resulting from tumor cell activity. The data support the hypothesis that sellar xanthogranulomas could occur as an inflammatory reaction secondary to the rupture and hemorrhage of a previous cystic process, thereby generating an expansion of the tumor body toward adjacent tissues. The information obtained from these cases contributes to the current knowledge about this disease's origin and clinical and histological evolution. However, the scarcity of patients and the observed phenotypic heterogeneity make its diagnosis still challenging. Undoubtedly, more investigations are needed to provide additional information in order to be able to achieve a more accurate diagnosis and effective treatment of this rare disease.

Pituitary adenoma associated with xanthogranuloma

Xanthogranuloma (XG) of the sellar region is a non-neoplastic inflammatory lesion characterized histologically by recent and remote hemorrhage, necrotic debris, fibrosis, chronic inflammation, and cholesterol clefts with associated foreign-body giant cells. The inflammatory lesion was recognized by the World Health Organization in 2000. XG of the sellar region is rare. Cases of pituitary adenoma (PA) with an associated XG (PA/XG) are extremely rare, with a total of 16 cases in the literature. PA/XG lacks specific clinical and radiologic signs, making pre-operative diagnosis challenging. Herein, we report a case of PA/XG, describe the radiologic and pathologic findings, and discuss the role of so-called silent or "subclinical pituitary apoplexy" in the possible histogenesis of PA/XGs.