An intraosseous lipoma in the frontal bone—a case report

Bilateral intraosseous lipoma of the maxillary tuberosity: A challenging entity

Lipomas can occur anywhere in the body where fat cells are present; however, intraosseous lipomas are rare. Although solitary lesions have already been reported in the gnathic bones, to the best of our knowledge, this is the first case of bilateral intraosseous lipoma. A 62-year-old woman was referred for evaluation of a swelling on both maxillary tuberosities. The radiographic examination showed a mixed radiolucent-radiopaque image with ill-defined borders on the right side of the maxilla, and an ill-defined radiolucency on the left side. Histologically, both sides revealed numerous mature adipocytes surrounded by immature bone and dystrophic calcification. The patient remains under follow-up and free of disease for 8 months. Due to the rarity of the intraosseous lipomas in the jaws, a literature review of the published cases was performed jointly with this unique case report.

Intraosseous Lipoma of the Calvaria in the Early Stage Resembling Normal Fatty Marrow

Intraosseous lipoma (IOL) is a benign bone tumor that usually arises from the lower limb and rarely arises from the skull. Radiological diagnosis of a typical case is not problematic due to its characteristic calcification and marginal sclerosis. Here, we report a case of calvarial IOL in the early stage lacking conventional radiopathological features. The patient is a 7-year-old girl who presented with a slow-growing protuberance on the vertex of the head. Computed tomography displayed a low-density mass without calcification that was continuous with the surrounding diploe. The mass was resected piece by piece for diagnostic and cosmetic reasons. Histologically, the specimen consisted of bony trabeculae and intertrabecular adipose tissue, which resembled normal fatty marrow. However, adipose tissue was considered neoplastic since it lacked hematopoietic elements. The final diagnosis of IOL was made by radiopathological correlation. This case suggests that IOL should be included in the differential diagnosis of diploic expansion, even if calcification is absent. The histology of an early-stage IOL resembles normal fatty marrow, but recognizing the absence of hematopoietic elements aids the diagnosis. Also, our literature review indicates that such cases are likely to be encountered in the calvaria than cranial base.

Large Intraosseous Lipoma of the Skull: A Case Report and Review of the Literature

BACKGROUND

Intraosseous lipomas occurring within the skull are rare. Currently, the known locations include the frontal bone, parietal bone, temporal bone, and ethmoid bone. Thus far, we have found only 12 cases of lipoma at the top of the forehead on the skull, and only 2 cases of recurrent intraosseous lipoma have been reported. The patient with intraosseous lipoma we have described was a 3-year-old boy, the youngest of the 12 known patients with intraosseous lipoma of the skull, and the patient had repeated relapses.

CASE DESCRIPTION

We report the history of a 3-year-old boy with a giant intraosseous lipoma in his left frontal region when he came to our hospital for treatment. The head computed tomography scan showed a left frontal plate with an oval low density, and the boundary was clear. The lesion affected the normal appearance of the child. He had experienced varying degrees of recurrent growth after 2 operations. At the last follow-up examination, the appearance of the patient had improved greatly.

CONCLUSIONS

For large intraosseous lipomas occurring in the skull, owing to its special position and the tendency for repeated relapses to develop, extending the excision is an effective surgical approach. For swelling involving a wide range, surgery should involve specialists in craniofacial surgery.

Intraosseous Lipoma of the Mandibula: A Case Report and Review of the Literature

Lipoma is a benign tumour originating from mature adipose tissue. It can occur in any place in the body where adipose tissue is located. Intraosseous lipoma is a very rare bone tumour. The authors present an infrequent case involving intraosseous lipoma of the mandible in a 32-year old man and provide a review of case studies documented earlier in the literature.

Giant Intradiploic Angiolipoma of the skull. Report of the first case with MR and histopathological characteristics reported in the literature and a review

Background:

Intraosseous Angiolipoma of the skull bone (IOAL) is a very rare bony lesion of the calvarium. This lesion occurs most commonly in the soft, subcutaneous tissue of the trunk. Only a single case of angiolipoma of the skull has been previously reported. The authors report the first case of giant IOAL of the calvarium evaluated by 3D CTS, MRI and full histopathological staining in a young lady treated surgically and with 23 months of follow up.

Case Description:

A 41-year-old female was admitted because of a prominent bulging on her right parietal region. Three dimensional CT and CT angiographic reconstruction of the cranium elucidated the geographical pattern of the lesion. MRI revealed a huge intraosseous right frontotemporoparietooccipital expansile lesion, nonhomogeneous but mostly hyperintense, in T1W images. In T2W images, the lesion was nonhomogeneously hyperintense and trabeculated with no perilesional edema. In the FLAIR-images, the lesion was trabeculated and nonhomogeneously hypointense. The lesion was excised totally followed by skull reconstruction and no recurrence after 23 months.

Conclusion:

We hypothesize that the possible pathogenesis of IOAL may be a kind of mutation or dedifferentiation of either a primary intradiploic hemangioma or lipoma changing its growth pattern with possibly more aggressive behavior.

Sphenoclival intraosseous lipoma in skull base

Intraosseous lipoma is a rare benign tumor, mostly occurring in lower limb especially in os calcis and the metaphyses of long bones. Intraosseous lipoma of the skull is even rarer, with 12 cases having been reported to involve the sphenoid bone in the literature. We present the third reported case of sphenoclival intraosseous lipoma in a 43-year-old man with headache, hyperprolactinemia and visual disturbance. Performed Magnetic Resonance Imaging (MRI) revealed pituitary macroadenoma as well as a mildly expansile lesion with high signal intensity on both T1- and T2-weighted sequences within the left greater wing of the sphenoid and the clivus. The patient refused to undergo surgical removal of pituitary macroadenoma and medical treatment was initiated instead; thereafter, follow up Computed Tomography (CT) and MRI scans revealed regression of the pituitary macroadenoma whereas the sphenoclival lesion was depicted as a welldefined fat-containing intraosseous lesion which showed no perceptible growth, 17 months later.

Radiological features of the intraosseous lipoma of the sphenoid

OBJECTIVE

Benign intraosseous lesions of the skull base are often identified in the course of routine radiological investigation. Imaging features associated with suspected intraosseous lipoma (IOL) can mimic more aggressive pathology. The features of this poorly described entity in the skull base were analyzed to aid the otolaryngologist in differentiation from other pathology.

STUDY DESIGN

Retrospective analysis of computed tomography (CT) and magnetic resonance imaging (MRI) images over the period from March 2007 to March 2009.

SETTING

Radiology service, tertiary hospital, Sydney, Australia.

METHODS

Images with diagnosis of incidental suspected IOL within the sphenoid were selected. Radiological features including trabecular pattern, secondary calcification, cortical bone thinning, and size and the presence of fat (defined as <-5 HU) were recorded.

RESULTS

Ten patients (5 male) were identified. Seventy percent had unilateral, single lesions occurring within the sphenoid bone. The mean size was 13.1 ± 5.6 mm (range, 4-21 mm). Fat was demonstrated in all lesions. There were 3 cases of multiple lesions occurring within the sphenoid bone. In addition, 61.5% were associated with cortical bone thinning and 46.2% with secondary calcification within the lesion. Changes to normal trabecular bone occurred: 46.2% with a partial loss of and 53.8% with a complete absence of trabecular pattern. Histopathologic confirmation of IOL is presented.

CONCLUSION

IOL is believed to be a more common benign intraosseous lesion within the skull base than previously reported. Cortical bone thinning and other features normally suggestive of aggressive pathology commonly occur. Otolaryngologists should be aware of these common lesions to avoid unnecessary further investigation.

A case of Proteus syndrome with lateral embryonal vein and frontal intraosseous lipoma

A patient with Proteus syndrome is reported with heretofore unreported features including a frontal intraosseous lipoma and a lateral embryonal leg vein (Servelle) associated with a venous malformation. These associated anomalies further broaden the phenotypic variability of Proteus syndrome.

Intraosseous lipoma. A clinical, radiologic, and pathologic study of 5 cases

Intraosseous lipoma is an uncommon tumor of bone with indistinct radiologic features that makes it diagnostically challenging to radiologists and pathologists. There is a need to familiarize these physicians with the radiographic and pathologic features of this lesion for the correct diagnosis. We described the radiologic and pathologic features of intraosseous lipoma in 5 women. In 4 patients, the tumors occurred in long bones, whereas in the fifth patient, the skull was involved. Patients' age ranged from 50 to 63 years. Plain radiographs of the long bones revealed well-circumscribed benign-appearing osteolytic lesions with sclerotic margins, whereas in the skull, a poorly defined lytic aggressive-looking lesion was observed. In the long bones, the lesions showed remodeling of the affected bone with matrix calcification, simulating bone infarcts. Microscopically, mature adipose tissue with fat necrosis, absence of hematopoietic elements, and dystrophic calcification corresponding to the calcified matrix seen on the plain radiographs were seen. The osteolytic skull lesion had large caliber thin-walled vasculature with occasional fibrin thrombi mimicking intramuscular hemangiomas of soft tissue. On plain radiographs, an intraosseous lipoma is usually seen as a rather benign-appearing osteolytic bone lesion with well-defined margins and a heavily calcified/ossified dense matrix. Plain radiographs alone cannot establish the diagnosis of intraosseous lipoma as it mimics several other benign and malignant bone lesions. Intraosseous lipoma often contains calcified necrotic fat with little mature adipose tissue and characteristically induces expansion/remodeling of the affected bone.