Central xanthoma of the jaw in association with Noonan syndrome

Unusual presentation of primary central xanthoma of the maxilla associated with impacted canine: An update on immunohistochemistry in the diagnosis

A xanthoma is an extremely rare condition that affects the soft tissues and bones and is characterized by a predominance of lipid-rich foamy histiocytes. The onset of xanthomas is frequently accompanied by primary or secondary hyperlipidemia. Primary bone xanthomas are very uncommon benign bone lesions that are not linked to hyperlipidemia. Histopathologically, they are distinguished by histiocytes, an abundance of foam cells or xanthoma cells that contain lipids, and a paucity of multinucleated giant cells. There have only been four reports of primary maxillary xanthoma in the medical literature. We present a rare primary intrabony xanthoma of the anterior maxilla in a 23-year-old normolipidemic female patient with solitary radiolucency. Using CD68, S-100, and CD1a immunohistochemical staining, it is possible to distinguish between macrophage/non-Langerhans histiocytes and Langerhans histiocytes. Therefore, a diagnosis of a central xanthoma of the jaws must be made.

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.

Benign fibrohistiocytic jaw lesions: a 48-year clinicopathologic analysis and review of the literature

OBJECTIVE

Intra-osseous fibrohistiocytic lesions have long been reported in the literature; evidence suggests they represent a heterogeneous group of reactive and neoplastic processes. This study evaluated a series of gnathic fibrohistiocytic lesions to identify and categorize their clinical, radiographic and morphologic spectrum.

STUDY DESIGN

A retrospective case search over 48 years was conducted for maxillary and mandibular intra-bony fibrohistiocytic lesions. Diagnoses were confirmed and demographic, radiographic, clinical and follow-up data was analyzed.

RESULTS

Fifty cases met the inclusion criteria. Most cases (80%) were found in the second through fourth decades (mean, 29 years). The most common location (86%) was the posterior mandible. Radiographic presentations varied, but a few patterns emerged, including a distinctive mottled, honeycomb type with punctate lucencies. All cases demonstrated fibrous components admixed with variable histiocytes. Eight cases (16%) were histiocyte-rich with dominant sheets of xanthoma cells. Immunohistochemical staining revealed strong CD68 and CD163 expression, along with variable smooth muscle actin staining. The vast majority (92%) of cases were treated conservatively. Available follow-up showed lesional stability in 17 cases (average, 85 months) with 2 recurrences (24 months each) and no evidence of malignant transformation.

CONCLUSIONS

This study is the largest to date of fibrohistiocytic gnathic lesions, revealing distinctive radiographic and histologic findings and characteristic clinical and immunophenotypic features. Available evidence suggests that most of these are indolent, slow-growing lesions amenable to conservative therapy.

Recurrent labial xanthoma infection in a patient with Neurofibromatosis-Noonan syndrome: case report and literature review

Introduction: Noonan Syndrome is a clinically and genetically heterogeneous syndrome, characterized by marked phenotypic variability. All the clinical manifestations of this syndrome are still not fully known. Observation: We present the case of a 58-year-old woman with a diagnosis of Neurofibromatosis-Noonan syndrome with SOS2 mutation, observed by her general practitioner for a recurrent left upper lip abscess despite drainage and antibiotic therapy. The anatomo-pathological result of the sample was in favor of an infected xanthoma. Discussion: The most common oral manifestation of Noonan syndrome includes malocclusion, dental anomalies and radiologic jaw lesions. Xanthomas of the lip have never been reported in this syndrome. Conclusion: Oral xanthomas could be one of the many oral clinical manifestations of Noonan Syndrome. However, more research is needed to understand clinical consequences of mutations in identified genes.

Primary Intraosseous Xanthomas of the Jaws: A Series of Six Cases Including an Example with Formation of Apoptosis-Related Hyaline Globules, So-Called "Thanatosomes"

Primary intraosseous xanthomas of the jaws (PIXJ) are rare and predominantly affect the posterior mandible (86%) of normolipemic patients, with a mean age of 30 years and no gender predilection. Clinically, PIXJ exhibit indolent biologic behavior; curettage is considered treatment of choice. Only 36 PIXJ have been reported. Apoptosis-related hyaline globules (HGs), also known as "thanatosomes", have not been previously reported in PIXJ. Cases diagnosed as xanthoma of bone were retrieved. Six cases fulfilling currently accepted criteria were identified and their clinicopathologic and immunohistochemical properties are presented herein. Mean age for PIXJ was 21.8 years (range = 12-33) and F:M ratio = 2:1. All cases presented as well-demarcated, unilocular or multilocular radiolucencies. Microscopically, PIXJ featured sheets of lipid-laden macrophages with eosinophilic or foamy cytoplasm. A secondary fibroblastic population lacking storiform pattern was evident in two cases. Adipocytes (3/6), peripheral neurovascular bundles (1/6), bone fragments (3/6) and dystrophic calcifications (3/6) were observed enclosed by the xanthoma cells. Notably, one case exhibited numerous, spherical, eosinophilic HGs containing apoptotic nuclei. PIXJ were consistently CD68(+) and negative for CD1α and S100. CD45 decorated lymphocytes and the membrane of foamy histiocytes. Xanthoma cells stained for lysozyme and plasma proteins including alpha-1 antitrypsin (AAT), IgG and IgA in one probed case. HGs were lysozyme(+), AAT(+), IgG(+), IgA(+), PAS(+) and diastase-resistant, and fuchsinophilic with Masson's trichrome. PIXJ represent infrequent, solitary, mandibular lesions with a predilection for the second and third decade of life. Thanatosomes associated with cell injury and death can be present in PIXJ.