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.

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.

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.

[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).

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.

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.

Xanthogranulomatous cholecystitis with histologic features suggestive of IgG4 related cholecystitis - A morphologic overlap with IgG4 related disease.

AIMS: Both xanthogranulomatous cholecystitis (XGC) and IgG4-related cholecystitis (IgG4-CC) are rare chronic fibroinflammatory tumefactive diseases of the gallbladder, which cause a strong confusion with resectable malignancy in view of their mass forming tendency with extension into the liver. We aim to study the histopathologic features of xanthogranulomatous cholecystitis with regard to IgG4-related cholecystitis in extended cholecystectomy specimens. METHODS AND RESULTS: Sixty cases of extended cholecystectomy with liver wedge resection, diagnosed as XGC on histopathology from January 2018 to December 2021 were retrieved from the archives. Representative sections were reviewed by two pathologists independently. Immunohistochemistry was performed for IgG4 and IgG4/IgG was derived. The cases were dichotomized in two groups on the basis of IgG4 positive plasma cells. Six cases with >50 IgG4 positive plasma cells had storiform fibrosis, IgG4/IgG ratio >0.40 and extra-cholecystic extension. Of these, 50 % had obliterative phlebitis and 66.7 % had perineural plasma cell wrapping. CONCLUSIONS: A small subset of XGC cases (~10 %) had morphologic overlap with IgG4-CC, but should not be overcalled as the diagnosis of IgG4-RD requires an integrative approach based on clinical, serologic and imaging criteria and not solely on histopathology.

Hemosiderotic Xanthelasmas. A New Clinicopathological Variant of Xanthelasma Palpebrarum or a Localized Variant of Xanthosiderohistiocytosis of the Eyelids?

ABSTRACT: Xanthelasma palpebrarum represent the most common subtype of cutaneous plane xanthomas. Xanthosiderohistiocytosis is considered a rare variant of xanthoma disseminatum, with only 4 cases reported to date. We report the case of a man with progressive pigmented lesions on the 4 eyelids that could correspond to hemosiderotic xanthelasmas or a localized variant of xanthosiderohistiocytosis.

Relationship between gastric xanthoma, gastric precancerous lesions, and gastric cancer: A retrospective study.

OBJECTIVE: To evaluate the relationship between gastric cancer and its precancerous lesions and gastric xanthoma. METHODS: Medical records of 47 736 patients who underwent gastroscopy in our center from January 2020 to December 2021 were reviewed. Patients' age, sex, endoscopic and histopathological findings, and the presence, number and location of gastric xanthoma were recorded. To investigate the detection rate of gastric xanthoma at different stages of gastric lesions, the participants were further divided into the chronic gastritis group (n = 42 758), the precancerous lesion group (n = 3672), and the gastric cancer group (n = 1306), respectively. RESULTS: The overall detection rate of gastric xanthoma was 2.85%, and it was most commonly observed in the gastric antrum (52.50%). In addition, gastric xanthoma was more common in men and more likely to be single lesion. It was most detected in the precancerous lesion group (8.39%), followed by the gastric cancer group (5.44%), and least in the chronic gastritis group (2.29%). Multivariate analysis showed that gastric xanthoma was closely related to precancerous lesions (odds ratio [OR] 3.197, 95% confidence interval [CI] 2.791-3.662, P < 0.001) and gastric cancer (OR 1.794, 95% CI 1.394-2.309, P < 0.001). CONCLUSION: Gastric xanthoma is closely related to gastric precancerous lesions and gastric cancer.

Verruciform Xanthoma: Clinical and Morphologic Spectrum Across Oral, Genital, and Cutaneous Sites.

BACKGROUND: Verruciform xanthoma (VX) is an uncommon, benign epithelial lesion of the oral mucosa. While this entity can also present extraorally, including on the skin and in anogenital areas, the variation in its histologic features in extraoral sites is not yet well defined. Differences in the demographics and morphologic features of oral versus extraoral VX were assessed to help facilitate the accurate diagnosis and management of this lesion. METHODS: After obtaining IRB approval, 110 cases of diagnosed VX were retrospectively collected from our institutional archives spanning from 2000 to 2022. Patient age, gender, available medical history, lesion appearance, and duration were obtained for each case. RESULTS: The median age was 55 years (range 13-86) with a male-to-female ratio of 1.2:1. The most common oral sites, in descending order, were the palate (n = 24, 22%), buccal mucosa (n = 18, 16%), gingiva (n = 16, 15%), and tongue (n = 13, 12%). Extraoral sites comprised 9% of all lesions, including the scrotum (9), vulva (2), cheek (1), wrist (1), gluteal region (1), and abdominal wall (1). The median size for all lesions was 6.0 mm, and extraoral lesions were associated with a 6.7 mm larger size compared to oral lesions (B ± SE: 6.7 ± 2.5 cm, p = 0.01). The lesions were most frequently pink or white in color and often described as papillary, pedunculated, verrucous, and/or exophytic. Microscopically, the presence of wedge-shaped parakeratosis, keratin projections above the epithelium/epidermis, and associated inflammation significantly differed between oral and extraoral lesions. Prominent wedge-shaped parakeratosis (p = 0.04) and keratin projections above the epithelium/epidermis (p < 0.001) were more prevalent in extraoral lesions. There was no significant link between keratin projections and epithelial atypia (p = 0.44). CONCLUSIONS: Familiarity with the broad morphological spectrum of VX, including the presence and degree of wedge-shaped parakeratosis, keratin projections above the epithelium/epidermis, and associated underlying inflammation, will be helpful in diagnosing it in unusual locations.

Possible roles of human mast cells in the formation of xanthelasma palpebrarum.

Cutaneous xanthoma consist of foam cells that originate from monocytes or macrophages and accumulate in perivascular areas of the skin. The main component of these cells is oxidized low-density lipoprotein (oxLDL). In this study, we show that mast cells surround the accumulated foam cells, suggesting their involvement in xanthoma formation. Coculture of THP-1 or U937 monocytes with the human mast cell line LUVA upregulated their uptake of oxLDL. Positive staining for intracellular cell adhesion molecule-1 (ICAM-1) at the borders between mast cells and foam cells was seen in pathological specimens of the most common cutaneous xanthoma, xanthelasma palpebrarum, and in cocultures. In the latter, ICAM1 messenger RNA levels were upregulated. The administration of anti-ICAM-1 blocking antibody inhibited the increase in oxLDL uptake by THP-1 or U937 monocytes cocultured with LUVA. Taken together, these results suggest a role for mast cells in the formation of xanthelasma palpebrarum and the involvement of ICAM-1 in this process.

Xanthogranulomatous endometritis with unilateral salpingo-oophoritis in a postmenopausal woman masquerading as a malignancy.

Xanthogranulomatous endometritis (XGE) is a rare pathological entity which is characterised by sheets of foamy histiocytes and lymphoplasmacytic infiltrates. This condition can mimic endometrial carcinoma. We report a case, clinically suspected as carcinoma of the endometrium/ovary, which was diagnosed as XGE with left salpingo-oophoritis on histopathology.

IgG4-related ophthalmic disease in association with adult-onset asthma and periocular xanthogranuloma: a case report.

A 54-year-old male presented with a three-year history of bilateral upper eyelid and peri-orbital swelling and adult-onset asthma. Histopathology of a left orbital biopsy showed lymphoid follicles with foamy macrophages and Touton giant cells. Clinical, histological and radiological features were consistent with adult-onset asthma and periocular xanthogranuloma. Treatment with rituximab led to a complete clinical and radiological remission. Nine years later, his condition relapsed with a biopsy of the left orbit and lacrimal gland demonstrating features of IgG4-related disease and adult-onset asthma and periocular xanthogranuloma. Immunohistochemistry showed increased numbers of IgG4+ plasma cells (290 per high power field) and an elevated IgG4+/IgG+ plasma cell ratio of 480%. Involvement by both disorders in the orbit and ocular adnexa of a single patient has not previously been reported in the literature, to the best of our knowledge, and suggests a possible aetiologic or pathophysiologic association.

Oral verrucous xanthoma with oral lichen planus: a case report.

Verrucous xanthoma is a rare benign muco-cutaneous lesion, whereas oral lichen planus is a chronic inflammatory disease relatively common in the clinical setting. Verrucous xanthoma and oral lichen planus can reportedly coexist according to foreign literature. Owing to the low incidence of verrucous xanthoma and the rarity of co-occurrence of these two diseases, the mechanism underlying the co-occurrence of the two diseases remains inconclusive. In this work, a case of oral verrucous xanthoma complicated with oral lichen planus was reported. Related literature was reviewed to discuss the clinical classification, pathological classification, and possible pathogenesis of the two diseases.