Clinical features of bilateral temporal bone xanthoma with LDLR gene mutation

Right Parietal Skull Xanthoma Characterized as a Metastatic Deposit

BACKGROUND

Xanthomas are benign lipomatous deposits that can be found systemically in various tissues including bones. Their presence in the skull remains a rare entity. Despite their benign characteristics, imaging modalities are often unable to distinguish them from malignant lesions. This leads to a diagnostic dilemma in patients with underlying malignancy. This case report highlights such a case where clinical history of prostate cancer and image findings were concordant with that of metastatic deposit in the parietal skull region.

CASE DESCRIPTION

This 65-year-old gentleman was diagnosed with prostatic adenocarcinoma. During systemic workup for his tumor, he was found to have a right parietal skull lesion. Magnetic resonance imaging of the brain, as well as a bone scan, were consistent with that of a metastatic deposit. As treatment would be drastically affected by the diagnosis, an excision biopsy was performed. The histology was consistent with that of a bone xanthoma.

CONCLUSIONS

Xanthomas are benign lesions that can be seen deposited in appendicular and axial skeleton. Skull lesions are rare with most case descriptions focusing on their presence in the frontoorbital regions and mandible and temporal bone. They usually have a benign course but may present with symptoms due to localized mass effect. Surgical intervention and histologic diagnosis may still be required in these lesions due to their lack of imaging characteristics that confirm their diagnosis through noninvasive methods.

Clinical and serum lipid profiles and LDLR genetic analysis of xanthelasma palpebrarum with nonfamilial hypercholesterolemia

BACKGROUND

XP is a flat xanthoma that usually presents as bilateral, symmetrical, soft, yellowish papules over the eyelids. The etiology of XP is unknown, but it may be related to complex heterozygous mutations.

AIMS

To investigate the lipid profiles, important clinical characteristics, and low-density lipoprotein receptor (LDLR) gene mutation in the patients suffering from xanthelasma palpebrarum (XP) with nonfamilial hypercholesterolemia.

PATIENTS/METHODS

The prospective study included 25 individuals of XP with nonfamilial hypercholesterolemia, and 30 controls neither with XP nor familial hypercholesterolemia (FH). Each one underwent detailed clinical examination, serum lipid profile, and LDLR gene detection at the 400th exon and the 1246th exon.

RESULTS

In our study, patients with XP were often not present with FH and family history. The mean serum cholesterol (CHOL) (5.20 ± 1.82) and the prevalence of carotid atherosclerosis (4.34 ± 0.78) were significantly higher in study group, while there was no statistically significant difference between two groups in terms of triglyceride (TG) (P = .38) and low-density lipoprotein (LDL) (P = .23). Unusually, the mean levels of high-density lipoprotein (HDL) (1.59 ± 0.31) in the study group were much higher than the controls (1.31 ± 0.30), and the LDLR gene mutation was not found.

CONCLUSION

Clinical and serum lipid profiles indicated that XP was sporadic and underlying lipid abnormalities especially higher HDL. XP did not occur with mutations in the LDLR gene at the two exons. We suggested too high HDL level may be contributed to pathogenesis of XP and XP is often not associated with FH.

[Bilateral temporal bone xanthoma associated with hyperlipidemia]

Presented clinical observation of a 42-year-old patient with bilateral xanthoma of the temporal bone, who has been treated for a long time for bilateral external otitis media, repeatedly mastoiditis. In this case, hyperlipidemia was detected only after the diagnosis of xanthoma was established. In this case, histological and clinical data helped to diagnose xanthomas and exclude chronic otitis media: the preservation of the auditory ossicles and hearing despite a large destruction of the temporal bone; satisfactory condition of the patient for many years in the presence of volumetric formations in both temporal areas extending into the cranial cavity, spreaded from the brain substance and not accumulating contrast according to computer and magnetic resonance imaging; normalization of hearing against the background of prolonged heating of the body - 'melting' of fats and opening the ear canal. Fistulas, through which a yellowish secret stood out either in the external auditory canal or in the behind-the-ear area, served as a kind of 'whisper valve', which made it possible to stop the pain syndrome and did not lead to the development of cerebral symptoms.

Central xanthoma of the mandible associated with hyperlipidemia: A rare presentation

Xanthoma is a common, self-limiting cutaneous lesion of non-Langerhans cell, lipid-laden foamy histiocytes that is often concomitant with hyperlipidemia. The intraosseous counterpart is rarely encountered and typically presents as a painless, expansile osteolytic process in the context of hyperlipidemia or normolipidemia. Only a scant number of gnathic xanthomas have been reported in the otolaryngologic literature. We report the clinical, laboratory, radiographic, histopathologic, immunohistochemical, and ultrastructural studies of a mandibular lesion discovered in an asymptomatic 16-year-old male, and associated with 2 previously unreported comorbidities, namely hyperlipidemia and vitamin D deficiency.

Central Xanthoma of the Jaw Bones: A Benign Tumor

Extragnathic xanthomas are seen in the bones or as soft tissue masses. They are often associated with hyperlipidemia and are considered as reactive or metabolic lesions. Only 19 cases of xanthomas of the jaws have been reported so far in the English literature. A total of ten cases of central xanthoma of the jaw bones were identified from the Oral and Maxillofacial Pathology biopsy services of the University of Washington and the Tufts University School of Dental Medicine, between the years 2000-2016. The demographic and clinical information on these cases was tabulated logically on the basis of age, gender, location and presence or absence of symptoms, extragnathic lesions and serum hyperlipidemia. Radiographic and histopathological features were also examined. The findings in these cases were correlated with those available from the previously reported cases. Majority of cases are seen in the second and third decades of life. There is no gender predilection. Jaw lesions presented as solitary radiolucencies with a predilection for the posterior mandible. Unlike maxillary lesions, pain and expansion are inconsistent findings in mandibular lesions. Jaw lesions are not associated with extragnathic bone or soft tissue involvement or a hyperlipidemia. The central xanthoma of the jaws is a unique benign tumor. Histopathologically, many other jaw lesions contain variable numbers of foamy histiocytes. Therefore, a diagnosis of a central xanthoma of the jaws must be made after excluding all other such histiocyte containing lesions. This requires correlation of histopathological findings with clinical and radiographic features.