Cerebral involvement in sitosterolemia.

BACKGROUND: Sitosterolemia, an autosomal recessive condition, is characterized by impaired metabolism of plant sterols. Clinical symptoms include skin xanthoma, premature atherosclerotic disease, arthritis, and unexplained hematological abnormalities. However, there is a dearth of studies on sitosterolemia-related brain damage. METHODS: This study focused on the family of two sitosterolemia patients who presented with severe hypercholesterolemia and xanthoma. Radiological examinations, biopsies, whole-exome sequencing (WES), and plant sterol tests were conducted. RESULTS: The index patient, a 66-year-old female, initially exhibited weakness in both lower limbs and later developed urinary and fecal incontinence. Neuroimaging showed that the falx of the brain had irregular fusiform thickening. Significant tissue edema was observed around the lesions in the bilateral frontal-parietal lobes. Pathological analysis of the biopsied brain lesion revealed extensive cholesterol crystal deposition and lymphocyte infiltration in the matrix. The index patient who experienced cerebral impairment and her sister both carried two compound heterozygous variants in ATP binding cassette transporter G5 (ABCG5). These included the nonsense variants NM_022436: c.751 C > T (p.Q251X) in exon 6 and NM_022436: c.1336 C > T (p.R446X) in exon 10. A notable increase in plant sterol levels was observed in the younger sister of the index patient. CONCLUSION: This study highlights a previously unreported neurological aspect of sitosterolemia. Imaging and pathology findings suggest that cholesterol crystals may be deposited in connective tissues such as the cerebral falx and pia mater through blood circulation.

Prevalence, Anatomical Distribution, and Risk Factors of Adipocytic Tumors and Xanthomas in Psittaciformes: 1096 Cases (1998-2018).

Adipocytic tumors are mesenchymal tumors that are commonly reported in psittacine birds; however, large-scale studies evaluating their prevalence and associated risk factors are lacking. A retrospective study of adipocytic tumors in psittacine birds was performed by reviewing pathology submissions from the University of California, Davis-Drury Reavill Pathology Database, containing 26 013 submissions from psittacine birds (1998-2018). Age, sex, genus, anatomic distribution, and pathological diagnosis were collected for each case when available. The prevalence, risk factors, and association with other lipid-accumulation disorders were reported. A total of 450 cases of lipoma, 129 cases of myelolipoma, 35 cases of hemangiolipoma, 31 cases of liposarcoma, and 451 cases of xanthoma were identified. The prevalence of adipocytic tumors and xanthomas on necropsy was 1.3% (158/11 737, 95% confidence interval [CI]: 1.1-1.6). Adipocytic tumors were identified in 27 genera. Amazona (odds ratio [OR] = 1.93, 95% CI: 1.24-2.99, p = 0.004), Myiopsitta (OR = 2.3, 95% CI: 1.0-5.2, p = 0.041), Melopsittacus (OR = 3.4, 95% CI: 2.1-5.5, p < 0.001), and Agapornis (OR = 3.5, 95% CI: 2.0-6.1, p < 0.001) had significantly higher odds of developing adipocytic tumors compared with other genera, whereas Ara had significantly lower odds (OR = 0.5, 95% CI: 0.3-0.9, p = 0.030). Age was also a significant risk factor for many types of adipocytic tumors. There was no significant association between general adipocytic tumor formation and atherosclerosis or hepatic lipidosis. Xanthomas were associated with atherosclerosis (OR = 1.88, 95% CI: 1.01-3.51, p = 0.048), but not hepatic lipidosis (p = 0.503). On necropsy, the trunk and air sacs were the most common sites of xanthoma formation, whereas the trunk and liver were the most common sites of lipoma and myelolipoma formation, respectively.

Solitary primary intraosseous xanthoma of the mandible in a 15-year-old boy: a case report.

BACKGROUND: A xanthoma is a rare bone condition consisting of a predominant collection of lipid-rich, foamy histiocytes. The central xanthoma of the jaws is a unique benign tumor. CASE REPORT: A 15-year-old Caucasian male has been presented to our department. He had radiological changes in the area of the left mandibular angle, with an area of diffuse osteolysis of 3.0 cm by 2.0 cm. Computed tomography reveals an area of diffuse osteolysis that starts from the distal root of the lower second molar and reaches the ascending process. A bone biopsy was performed, which revealed a benign proliferative process composed of histiocytic cells involving and infiltrating trabecular bone in a background of loose fibrous connective tissue devoid of any other significant inflammatory infiltrate. The size of the formation was 2.9 cm by 2.0 cm. Immunohistochemical staining for CD68 was strongly positive and negative for S-100 and CD1a. From routine blood tests, cholesterol, triglycerides, and blood sugar are within normal values, which excludes systemic metabolic disease. Subsequent to the surgical intervention, the patient underwent postoperative assessments at intervals of 14, 30, 60 days, and a year later, revealing the absence of any discernible complications during the aforementioned observation periods. CONCLUSION: The diagnosis of primary xanthoma of the mandible is rare and can often be confused with other histiocytic lesions. A differential diagnosis should be made with nonossifying fibroma and Langerhans cell histiocytosis, as in our case. In these cases, immunohistochemistry with CD 68, S-100, and CD1a, as well as blood parameters, are crucial for the diagnosis.

Clinicopathologic and Molecular Characterization of Xanthomatous Giant Cell Renal Cell Carcinomas: Further Support for a Close Morphologic Spectrum to Eosinophilic Solid and Cystic Renal Cell Carcinomas.

A recent study described a rare subtype of tuberous sclerosis complex ( TSC )-mutated renal cell carcinoma primarily characterized by Xanthomatous giant cell morphology. Only 2 cases in young individuals have been reported so far, making the correct diagnosis challenging from a pathological perspective. It remains unknown whether this tumor represents an independent subtype or belongs to other TSC -mutated tumors. We conducted a clinicopathologic evaluation and immunohistochemical profiling of 5 cases of Xanthomatous Giant Cell Renal Cell Carcinoma (XGC RCC) with confirmed TSC2 mutations through targeted DNA sequencing. In addition, we analyzed transcriptomic profiles using RNA-seq for the following samples: XGC RCC, Low-grade Oncocytic tumors (LOT), High-grade Oncocytic tumors/Eosinophilic Vacuolar Tumors (HOT/EVT), Eosinophilic Solid and Cystic Renal Cell Carcinomas (ESC RCC), Chromophobe cell Renal Cell Carcinomas (ChRCC), Renal Oncocytomas (RO), clear cell Renal Cell Carcinomas (ccRCC), and normal renal tissues. There were 2 female and 3 male patients, aged 22 to 58 years, who underwent radical nephrectomy for tumor removal. The tumor sizes ranged from 4.7 to 9.5 cm in diameter. These tumors exhibited ill-defined boundaries, showed an expansive growth pattern, and featured distinctive tumor giant cells with abundant eosinophilic to Xanthomatous cytoplasm and prominent nucleoli. All tumors had low Ki-67 proliferation indices (<1%) and demonstrated immune reactivity for CD10, PAX8, CK20, CathepsinK, and GPNMB. Next-generation sequencing confirmed TSC2 mutations in all cases. RNA sequencing-based clustering indicated a close similarity between the tumor and ESC RCC. One patient (1/5) died of an accident 63 months later, while the remaining patients (4/5) were alive without tumor recurrences or metastases at the time of analysis, with a mean follow-up duration of 43.4 months. Our research supports the concept that Xanthomatous giant cell renal cell carcinoma (XGC RCC) shares clinicopathological and molecular characteristics with ESC RCC and shows a relatively positive prognosis, providing further support for a close morphologic spectrum between the two. We propose considering XGC RCC as a distinct subtype of ESC RCC.

Family sitosterolemia: report of two cases in Colombia. / Sitosterolemia familiar: reporte de dos casos en Colombia.

Sitosterolemia is an autosomal recessive and very rare disease. Its main characteristic is that there is a greater absorption and a decrease in the excretion of sterols, which leads to them being deposited in tissues. It is given by mutations in the ABCG5 or ABCG8 genes found on chromosome 2p21. In this clinical note, we describe the first two patients with familial sitosterolemia described in Colombia, brothers, one of them with xanthomas in extremities as the only symptom, and the other, completely asymptomatic. Genetic studies were performed as a diagnostic test in both patients, where a pathogenic homozygous variant could be identified in the ABCG8 gene in the first case (symptomatic), and a heterozygous variant in the ABCG8 gene in the second case (asymptomatic); the first patient has responded to treatment with ezetimibe. In conclusion, xanthomas should be studied in depth in pediatric age as they may be the only visible sign of such complex and hereditary diseases as familial sitosterolemia, which can be controlled and prevent cardiovascular complications of the disease.

A case of progressive xanthogranulomatous pancreatitis with splenic abscess.

Xanthogranulomatous inflammation is a chronic inflammatory reaction microscopically characterized by aggregation of foamy histiocytes, fibrous tissue, and infiltration of various inflammatory cells. In contrast to xanthogranulomatous inflammation in the gallbladder or kidney, xanthogranulomatous pancreatitis is rare. We herein present a case of xanthogranulomatous pancreatitis in a patient who underwent distal pancreatectomy with splenectomy under preoperative suspicion of a pancreatic pseudocyst or pancreatic tumor. A 77-year-old woman with a 1 month history of epigastric pain, anorexia, and general fatigue was admitted to our hospital. Contrast-enhanced computed tomography revealed a cystic mass with ill-defined margins at the pancreatic tail together with a splenic abscess. Contrast-enhanced endoscopic ultrasound detected a hyperechoic cystic lesion at the tail of the pancreas with heterogeneous internal echogenicity, and part of the intra-cystic content was enhanced by the contrast agent. Endoscopic retrograde cholangiopancreatography showed a cystic lesion at the tail of the pancreas that continued into the main pancreatic duct, and the main pancreatic duct was slightly narrowed downstream of the cystic lesion. Pancreatic juice cytology revealed suspicious cells, leading to the possibility of intraductal papillary mucinous carcinoma. Distal pancreatectomy with splenectomy was performed, and the histopathological diagnosis was xanthogranulomatous pancreatitis with no malignant findings.

Xanthoma of the Jaw Bones: Cases Series and Review of Literature.

BACKGROUND: Intraosseous xanthomas are rare benign lesions sometimes associated with excess lipid production. Xanthoma of the jaw bones (XJB) was first reported in 1964, and fewer than 50 cases have been reported in the English literature to date. The etiopathogenesis of XJB is highly suggestive of a reactive process or a metabolic condition. METHOD: Seven cases of XJBs were retrieved from the archives of 4 oral and maxillofacial pathology services. Clinical, radiographic and histopathologic features of all these cases were retrospectively analyzed. Immunohistochemical (IHC) stains for S100 and CD68 were performed. RESULTS: All seven cases involved the mandible. Patients' age ranged between 13 and 69 years with an evenly distributed female to male ratio. One patient had a medical history of hyperlipidemia, but the medical and dental histories of the others were unremarkable. For most cases, XJB was an incidental finding discovered during routine radiographic examination. Swelling and cortical expansion were noted in a few cases. Radiographically, cases typically presented as either well-defined multilocular or unilocular lesions, which were either radiolucent or mixed radiolucent/radiopaque. All the lesions were treated with surgical curettage and no recurrence was observed during subsequent follow-ups. Each of the seven cases exhibited sheets of foamy macrophages. The diagnosis is established by exclusion of entities with overlapping microscopic features and involved correlation with the clinical, histological, radiographic and IHC profiles. Immunohistochemically, all the cases expressed diffuse positivity for CD68 and were negative for S100. CONCLUSION: XJB is a rare lesion of unknown etiology, which may mimic other benign or reactive jaw lesions. Due to its rarity and the potential diagnostic challenges it presents, clinicians must remain vigilant and consider CXJ in their differential when assessing radiolucent jaw anomalies.

[Xanthogranulomatous adrenalitis : A rare and difficult differential diagnosis of adrenal gland tumors]. / Xanthogranulomatöse Adrenalitis : Seltene und schwierige Differentialdiagnose von Nebennierentumoren.

A radiologically diagnosed tumor in a 29-year-old woman with a fever of around 39 °C was operated on under the suspicion of cholecystitis or a liver abscess. A solid tumor was found in the adrenal gland and resected. The frozen section findings did not reveal a clear diagnosis of entity and assignment. Histologically, the tumor was found to consist of densely clustered large histiocyte-like cells with expression of vimentin, CD68, and CD163 as well as negativity for keratin, langerin, and SMA. We diagnosed xanthogranulomatous adrenalitis and discussed the differential diagnoses (Langerhans cell histiocytosis, Rosai-Dorfman disease, malakoplakia, Erdheim-Chester disease).

A Case Report of Craniofacial Intraosseous Xanthoma in a Patient Seeking Facial Feminization Surgery.

BACKGROUND: Fibrous dysplasia (FD) is a benign developmental disorder of the bone that causes normal skeletal tissue to be replaced by excess fibrous tissue and poorly differentiated osteoblasts. Intraosseous xanthomas are benign intraosseous tumor growths characterized microscopically by the presence of lipid-laden foamy histiocytes, often with cortical expansion or disruption. Although FD commonly occurs in craniofacial bones, primary intraosseous xanthomas of the skull or facial skeleton are extremely rare. Although 2 distinct conditions, each may be difficult to differentiate on CT imaging when occurring in the facial skeleton. METHODS: We report a case of an incidental finding on craniofacial CT of a frontal bone lesion originally thought to be FD. The finding was in a 55-year-old transgender woman who was assigned male at birth before receiving multiprocedural facial feminization surgery. RESULTS: The clinical features, radiological findings, and treatment are discussed. Postoperatively, the patient had no sequelae secondary to facial feminization surgery or to the orbital lesion biopsy procedure. Bone graft appeared stable on CT imaging, although FD did not appear to resolve completely. CONCLUSIONS: Diagnosis of such lesions is challenging and may require both radiographic and histopathologic assessment. As in the case of this patient, intraosseous xanthomas may also be misdiagnosed as other benign lesions such as FD. In most known cases, surgical intervention leads to complete resolution without recurrence of the lesion.

Secondary vs. primary pituitary xanthogranulomas: which yellow is more mellow?

Pituitary xanthogranulomatomas (XG) are a rare pathological entity caused by accumulation of lipid laden macrophages and reactive granuloma formation usually triggered by cystic fluid leakage or hemorrhage. Our aim was to compare clinical characteristics and presenting features of patients with secondary etiology of XG and those with no identifiable founding lesion (primary -"pure" XG) in order to gain new insights into this rare pituitary pathology. In a retrospective review of 714 patients operated for sellar masses, at tertiary center, we identified 16 (2.24%) with histologically confirmed diagnosis of pituitary XG over the period of 7 years (2015-2021). Patients were further analyzed according to XG etiology: "pure"- XG (n = 8) with no identifiable founding lesion were compared to those with histological elements of pituitary tumor or cyst - secondary XG (n = 8). We identified 16 patients (11 male), mean age 44.8 ± 22.3 years, diagnosed with pituitary XG. Secondary forms were associated with Ratke's cleft cyst (RCC, n = 2) and pituitary adenoma (PA, n = 6). The most common presenting features in both groups were hypopituitarism (75%), headache (68.5%) and visual disturbances (37.5%). Predominance of male sex was noted (males 68.75%, females 31.25%), especially in patients with primary forms. Patients with primary pituitary XG were all males (p = 0.0256) and more frequently affected by panhypopituitarism (87.5% vs. 25%, p = 0.0406) compared to patients with secondary causes. Hyperprolactinemia was noted in pituitary tumor group with secondary etiology only (p = 0.0769). Majority of lesions were solid on magnetic resonance imaging - MRI (81.25%). Distinct clinical phenotype was observed dependent on the etiology of XG.

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.

Deep-learning models for differentiation of xanthogranulomatous cholecystitis and gallbladder cancer on ultrasound.

BACKGROUND: The radiological differentiation of xanthogranulomatous cholecystitis (XGC) and gallbladder cancer (GBC) is challenging yet critical. We aimed at utilizing the deep learning (DL)-based approach for differentiating XGC and GBC on ultrasound (US). METHODS: This single-center study comprised consecutive patients with XGC and GBC from a prospectively acquired database who underwent pre-operative US evaluation of the gallbladder lesions. The performance of state-of-the-art (SOTA) DL models (GBCNet-convolutional neural network [CNN] and RadFormer, transformer) for XGC vs. GBC classification in US images was tested and compared with popular DL models and a radiologist. RESULTS: Twenty-five patients with XGC (mean age, 57 ± 12.3, 17 females) and 55 patients with GBC (mean age, 54.6 ± 11.9, 38 females) were included. The performance of GBCNet and RadFormer was comparable (sensitivity 89.1% vs. 87.3%, p = 0.738; specificity 72% vs. 84%, p = 0.563; and AUC 0.744 vs. 0.751, p = 0.514). The AUCs of DenseNet-121, vision transformer (ViT) and data-efficient image transformer (DeiT) were significantly smaller than of GBCNet (p = 0.015, 0.046, 0.013, respectively) and RadFormer (p = 0.012, 0.027, 0.007, respectively). The radiologist labeled US images of 24 (30%) patients non-diagnostic. In the remaining patients, the sensitivity, specificity and AUC for GBC detection were 92.7%, 35.7% and 0.642, respectively. The specificity of the radiologist was significantly lower than of GBCNet and RadFormer (p = 0.001). CONCLUSION: SOTA DL models have a better performance than radiologists in differentiating XGC and GBC on the US.

Urachal xanthogranuloma: a rare but important case presenting as a urachal mass.

BACKGROUND: A urachal mass is a relatively rare presentation to the urologists' practice, often requiring radical surgical excision for a definitive diagnosis. Xanthogranulomatous inflammation of the urachus is an extremely rare entity with few cases reported worldwide, and to the best of our knowledge, no cases reported in the western world. CASE PRESENTATION: In this case, a 55-year-old male patient presented with bothersome lower urinary tract symptoms and computed tomography findings demonstrating a urachal mass that was worrisome for urachal carcinoma. Following surgical intervention, histopathology revealed urachal xanthogranuloma. Post-operatively, the patient recovered well, and eventually, he had symptomatic and radiologic improvement. CONCLUSION: This case brings awareness to a rare presentation of a urachal mass-urachal xanthogranuloma. While operative intervention was both diagnostic and therapeutic, we highlight the challenge in differentiating between benign and malignant processes for urachal masses. Herein, we show the importance of including urachal xanthogranuloma in the differential diagnosis of a urachal mass to prevent further morbidity associated with the treatment of this disease.