Osteolipoma of head and neck - a review

Abstract Objective: Due to the rarity of osteolipoma, current knowledge and understanding of its' clinical presentation, management, radiological features, histological characteristics, and prognosis are lacking and can present a clinical conundrum to clinicians and histopathologist alike, given wide range of differential diagnoses. This paper aims to compile, analyse and present details to augment the available literature on osteolipoma in the head and neck. Methods: A comprehensive literature search on PUBMED/MEDLINE, EMBASE, CINAHL and Science Citation Index, Google scholar and Cochrane database for osteolipoma in head and neck was performed up to the 1st May 2021. Reference lists from the relevant articles were then inspected and cross-referenced and any other pertinent publications were added to the review. Results: A total of 38 cases were identified from the literature. The commonest sites of involvement within the head and neck region were the oral cavity in 21 (56.8%) patients, followed by the neck in 7 (19.0%) patients. 29 (78.4%) patients presented with soft tissue swelling or mass making it the most common presenting feature. All patients had the tumour excised surgically; of which 18 (48.6%) were excised via transoral approach and 6 (16.2%) via open transcervical approach including 1 lateral pharyngotomy. 12 papers documented long-term follow-ups (median 12 months) with no recurrence. Only 1 regrowth was reported after 5-years. Conclusions: Osteolipoma is a rare soft tissue neoplasm which has a wide range differential diagnosis including malignant processes. Recognising this benign tumour through an awareness of presenting sign and symptoms, radiological features and histopathology findings is important for patient reassurance as well as avoiding unnecessary radical treatment.

Osteolipoma of leg masquerading as osteoid osteoma: A case report

Lipomas are the most common, subcutaneous, and slow-growing tumors composed of fat (adipose tissue). Out of many types of these benign tumors, ossifying lipoma (osteolipoma) is the rarest subtype. Here, randomly distributed trabeculae of lamellar bone are seen within mature adipose tissue. They are featured only as isolated case reports and small case series, thus the true incidence is not known. The most common site for osteolipoma is the head and neck region and they are rarely reported in the lower extremities. Herein, we discuss the case of a 19-year-old man who presented with a progressively enlarging painful mass in the left leg. Radiology was typical of osteoid osteoma. Excision was performed and histopathological examination confirmed the lesion as osteolipoma with no evidence of malignancy. No recurrence of the tumor was observed after 2 years of follow-up. Although osteolipoma is a rare entity, the differential diagnosis of the lesion can be kept in mind whenever we encounter ossification within the adipose tissue.

Synovial osteolipoma.

Intraarticular synovial osteolipoma is an extremely rare tumor. Only two cases have been reported earlier to the best of our knowledge. It is a rare histological variant of lipoma, which contains mature lamellar bone. The largest tumor reported so far in the joint is 3 cm × 4 cm. Knee is a most common site. We report a large osteolipoma measuring 12 cm × 10 cm in the knee.

Pure Intramuscular Osteolipoma

Ossified lipoma or osteolipoma are rarely reported. It is defined as a histologic variant of lipoma that has undergone osseous metaplasia. Osteolipoma presents with a dominant osseous component within a lipoma. We report a case of a histologically confirmed osteolipoma on the nuchal ligament independent of bone. The patient was a 51-year-old female who presented with a 5-year history of a painless, progressively enlarging mass on the posterior neck. Computed tomography and magnetic resonance imaging showed a circumscribed mass compatible with fat between the C2 and C6 spinous processes with a large calcified irregular component. The mass with dual components was totally removed under general anesthesia and no recurrence was observed after 6 months of follow-up. We also reviewed the clinicopathologic features of previously reported osteolipomas in the literature and suggest that although osteolipoma is a rare variant of lipoma, it should be considered in the differential diagnosis when a lipoma of the posterior neck mixed with a bony component is encountered.

A Case Report of Lipoma with Chondro-Osteoblastic Metaplasia

Lipomas, which are benign adipose tissue tumors, are the most common tumors of mesenchymal origin in humans. Some variants of lipoma have been described according to the type of tissue present. A rare variant consists of a lipoma with osseous or cartilaginous metaplasia. We present the case of a lipoma with chondro-osteoblastic metaplasia of right buttock in a 57-year-old male. He was referred for a painless mass on the right lateral margin of the buttock, and present for about 1 month. Magnetic resonance images revealed a 12x8x4 cm sized mass with secondary degeneration focally, involving deep portion of the right gluteus maximus muscle, and protruded to adductor magnus muscle. T1 weighted images showed signal enhancement within the mass. He underwent complete resection of the tumor. No recurrence was observed after five years follow-up. Lipoma with chondro-osteoblastic metaplasia is extremely rare disease. Here, we report it along with the corresponding literature.

Interhemispheric Osteolipoma with Agenesis of the Corpus Callosum

Osteolipoma is an ossified lipoma with distinct components of fat and bone. We present a case of interhemispheric osteolipoma associated with total agenesis of the corpus callosum. A 20-year-old man complained of severe headache, nausea and vomiting. Brain computed tomography showed a low-density mass in an interhemispheric fissure, with high T1 and T2 magnetic resonance signals compatible with fat. The mass measured 4.9 x 2.9 cm in size and showed peripheral calcifications. There was another small piece of same signal mass within the lateral ventricular choroid plexus. The interhemispheric lesion was removed by an interhemispheric approach. Osteolipoma is rare in interhemispheric region, however, it should be a differential diagnosis of lesions with fat intensity mass and calcifications.