Intraosseous lipoma of the distal femur: MRI appearance

Intraosseous Lipoma of the Carpus: A Report of 2 Cases and a Review of the Literature

ABSTRACT

Intraosseous lipoma is a very rare benign lipoma, accounting for less than 0.1% of primary bone tumors. Incidentally found in most cases, it frequently involves the metaphysis of the long bones of the lower extremity or calcaneus but rarely occurs in the upper extremity. Intraosseous lipoma of the carpal bones, especially, has yet to be reported, except for 3 cases of scaphoid and capitate involvement. Herein, we report 2 cases of intraosseous lipoma in the capitate and hamate bones with a literature review. Two patients complained of wrist discomfort despite conservative treatment and were diagnosed by computed tomography, magnetic resonance imaging, and surgical biopsy. They were treated with intralesional curettage and autologous bone graft, and their symptoms improved and showed no evidence of recurrence, both clinically and radiologically.

Symptomatic Intraosseous Lipoma of the Calcaneum

Intraosseous lipomas are rare bone lesions that can affect any part of the skeleton. In the calcaneum, they are, generally, asymptomatic, but in some cases, patients may complain of pain, swelling or tenderness. Well-conducted radiography and MRI examinations can lead to an accurate diagnosis. In most cases, patients could benefit from conservative means of treatment, but in long-lasting symptomatic cases, surgical treatment may be a good option. The purpose of this article is to increase clinicians’ awareness of this lesion as a possible cause of heel pain and to describe a case of a symptomatic intraosseous lipoma of the calcaneum who underwent curettage and bone cement filling after failure of conservative treatment.

Intraosseous "Lipoma" of the Calcaneus Developing in an Intraosseous Ganglion Cyst

Intraosseous lipomas are rare primary bone tumors, most common to the calcaneus. There are several proposed theories of the natural etiology of intraosseous lipomas; however, all lack definitive support. In this report, an 18-year-old man presented with radiologic evidence of a simple bone cyst of the calcaneus. Over a 4-year period, the patient was followed with interval magnetic resonance imaging. The cyst demonstrated progressive development of peripheral intralesional fat with final magnetic resonance imaging features characteristic of an intraosseous lipoma. To our knowledge, this is the first longitudinal study that shows gradual peripheral fat deposition within an intraosseous ganglion cyst, illustrating a potential cause of intraosseous lipomas of the calcaneus.

Aggressive intraosseous lipoma of the intermediate phalanges of the thumb

Intraosseous lipomas occurring in the bones of the upper limbs are very rare. The tumor often occurs in long bones, especially the calcaneus. Usually patients with intraosseous lipomas present with mild clinical features. Thus far, bone destruction caused by the tumor has not been reported. The present study reported a case of an aggressive intraosseous lipoma that developed in the intermediate phalanges of the thumb. This is an extremely rare case with extraosseous development, which occurred at a rare site. A 47-year old woman presented to us with right thumb pain and swelling. Computed tomography and magnetic resonance imaging revealed a mass extending to the outer edge of the phalangeal bone. The patient was treated with surgery the remove the tumor. Artificial bone was used to refill the area due to the lack of cancellous bone. During the clinical management of lipomas, it is important to consider that intraosseous lipomas may spread out of the bone; moreover, the tumor should be removed immediately to help reduce the possibility of bone destruction.

Intraosseous Lipoma: 18 Years of Experience at a Single Institution

Background

Intraosseous lipoma is a very rare lesion that constitutes no more than 0.1% of all bone tumors. We analyzed 21 cases of intraosseous lipoma at a single institution for clinical and radiographic characteristics.

Methods

A retrospective study was performed on 21 pathologically confirmed intraosseous lipomas treated in our hospital from 2000 to 2017. Simple X-ray and magnetic resonance imaging findings and medical records were reviewed. Patients' age, sex, and clinical symptoms were investigated. From the radiographic images, the site of the lesion, calcification, bony expansion, and stage of the lesion were evaluated. Correlations between the degree of involution and clinical symptoms were analyzed.

Results

The mean age of patients was 50 years (range, 20 to 67 years), and there were 13 males and eight females. The mean lesion size was 6.1 cm (range, 2.5 to 13.6 cm). The most common anatomical site of the lesion was the femur (seven cases), and three cases occurred in flat bones such as the ilium and scapula. Visual analogue scale score for pain was 3 to 6 in 15 patients. There were no complaints of functional limitation. There was no correlation between the degree of degeneration and clinical symptoms (p = 1.000). Curettage was performed as a surgical treatment in 20 patients, and bone graft was performed using a bone chip. Excision was performed in one patient. Pain was resolved in seven of 11 patients with a complaint of preoperative pain; intermittent pain remained in four cases. There was no local recurrence or malignant change during the follow-up.

Conclusions

There was no correlation between the degree of degeneration and clinical symptoms. Pain was the most common clinical symptom, but it was rarely accompanied by functional limitation. However, it is important to distinguish it from other pain-inducing disorders. The incidence of intraosseous lipomas is low, and detection based on various imaging findings can be difficult. Clear understanding of the radiographic findings and symptoms of intraosseous lipoma is helpful for diagnosis and differentiation.

[A rare cause of talalgia]

Une talalgie est l'une des symptômes les plus courants du pied. LeLipome intra-osseuse est l'un des plus rares tumeurs osseuses trouvées dans le calcanéum. Nous rapportons une observation d’un patient s’est présenté à la consultation avec des douleurs intermittentes chroniques et spontanées du talon, chez qui les investigations cliniques et radiologiques ont retenu un diagnostic d’un lipome du calcanéum.Le but de cet article est de sensibiliser les cliniciens à l'existence de cette lésion inhabituelle.

Endoscopic surgery in athletes with a symptomatic calcaneal lipoma

PURPOSE

This study shows that endoscopy is an effective treatment modality for athletes with a symptomatic calcaneal lipoma.

METHODS

Between 2013 and 2016, five professional athletes with symptomatic calcaneal lipoma underwent endoscopic-assisted curettage and bone graft treatment. Lipoma size was measured by magnetic resonance imaging (MRI) and rated using the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale (AOFAS). All athletes were followed up for 12 months postoperatively and monitored on return to previous activity level.

RESULTS

The mean ankle-hindfoot scale score improved from a preoperative 71.3 +/-3.9 points (median 67-81) to a postoperative 97.8 +/-3.4 points (median 89-100). Radiological assessment revealed no recurrence or pathologic fracture, with adequate bone fill-up in all 5 cases. All athletes returned to their previous level of activity within 8 weeks of surgery (mean period 7.2 weeks, median 5-8 weeks).

CONCLUSION

Endoscopic surgery can be used as a valid treatment tool for athletes with a calcaneal lipoma. It allows for a safe and early return to sports activities and minimises risk for recurrence and pathological fracture after initial return to play.

LEVEL OF EVIDENCE

IV.

Intraosseous Lipoma of the Proximal Radius with Extra Osseous Extension leading to Posterior Interosseous Nerve Compression: HRUS Diagnosis

INTRODUCTION

Benign musculoskeletal lipomatous lesions are common in both soft tissue and bone. Imaging features of benign lipomatous lesions are often pathognomonic. Ultrasound (US) has been used to examine both soft tissue and bone tumors, allowing targeted CT or MRI examination of the region of interest.

CASE REPORT

A 46-year-old female presented with a four year history of palpable mass lesion just below the lateral aspect of right elbow with clinical evidence of posterior interosseous nerve compression. X-ray showed the presence of a radiolucency mass in relation to radius. HRUS demonstrated a hyperechoic mass in soft tissue with a focal irregularity in bony cortex of radius. The mass lesion compressed the posterior interosseous nerve.

CONCLUSION

Although CT and MRI diagnose them accurately, but ultrasound characteristics are also conclusive for extra osseous component. This case highlights the importance of HRUS for evaluation of musculoskeletal tumors and any secondary changes in a readily available cost effective dynamic modality and thus guide for treatment planning accordingly.

Calcaneal intraosseous lipoma: a case report and review of the literature

Intraosseous lipomas are rare benign bone tumors. This benign neoplasm has been reported to occur in the calcaneus as well as the proximal femur. In the past, the relative absence of symptoms and radiographic similarity to a bone cyst has accounted for underdiagnosis of intraosseous lipoma. The case presented in this article was diagnosed with the help of computerized tomography and histopathologic analysis, after which the patient was treated by means of curettage and packing with calcium phosphate bone graft substitute. The purpose of this article is to increase awareness among clinicians of the existence of this unusual lesion.

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.

Surgery is not always necessary in intraosseous lipoma

Intraosseous lipoma is the rarest primary bone tumor, is usually asymptomatic, and is often discovered incidentally during unrelated investigations. Lipomas usually undergo varying degrees of involution, with necrosis, cyst formation, and calcification. Careful radiological-pathological correlation is required to avoid misinterpretation. This study describes 12 intraosseous lipomas in 11 patients (6 men, 5 women; mean age, 36 years [range, 25-50 years]; mean follow-up, 5 years [range, 2-11 years]). The lesions were located in the calcaneus in 7 patients (bilaterally in 1 patient), the tibia in 2, the femur in 1, and the ilium in 1. All lesions were asymptomatic and discovered incidentally except in 4 patients (5 lesions). Curettage and bone grafting were performed after biopsy in 4 lesions; and in 1 patient, curettage, bone grafting, and reconstructive surgery were performed after pathologic fracture. The remaining 7 patients were followed up conservatively. Although definite diagnosis of an intraosseous lesion is possible only by histopathologic examination, computed tomography and magnetic resonance imaging findings of intraosseous lipoma are typical, and most patients' symptoms are relieved by conservative means. For this reason, we believe that in patients with no signs of an impending pathologic fracture or suspicion of malignancy, clinical and radiological follow-up is sufficient. However, since intraosseous lipoma is an uncommon bone tumor, physicians should be familiar with the radiological features of this lesion for the correct diagnosis.

Intraosseous lipoma in the femoral shaft mimicking a bone metastasis on bone scintigraphy

Primary intraosseous lipoma is a rare benign neoplasm of mature fat cells arising within the bone marrow, most commonly within the metaphysis of long bones. Involvement of the epiphysis or diaphysis is uncommon. An intraosseous lipoma typically shows no abnormal uptake of a bone-seeking agent. Bone scintigraphy demonstrated a focal area of uptake in the right femoral shaft mimicking a bone metastasis in a 52-year-old man with basal cell carcinoma of the face. Plain radiography showed a well-defined radiolucent lesion with endosteal erosion in the intramedullary portion. MRI showed no fat tissue in the lesion. Histology confirmed intraosseous lipoma with dystrophic calcification and myxomatous degeneration.

Multiple intraosseous lipomatosis: a case report

INTRODUCTION

Intraosseous lipoma is an uncommon entity that presents almost exclusively as a solitary lesion. Multiple intraosseous lipomas are exceedingly rare with only a few cases being reported in the literature.

CASE PRESENTATION

We present a case of 43-year-old African American female who presented with left leg and left wrist pain. The initial radiographs revealed well-defined radiolucent lesions in multiple bones involving the left wrist and the left lower limb. The magnetic resonance demonstrated multiple lesions, which showed high signal on the T1 and low signal on the fat suppressed T2 images. This favored the diagnosis of intraosseous lipomatosis that was confirmed by biopsy.

CONCLUSION

Multiple intraosseous lipomatosis is an uncommon but important differential for multiple radiolucent lesions on the plain radiographs. This condition can lead to pathological fractures. Magnetic resonance imaging can aid in providing an accurate diagnosis. The awareness of this condition can help the clinician in guiding the correct diagnosis and management.

Intraosseous lipoma: radiological findings

OBJECTIVE: Intraosseous lipomas may be less rare lesions than previously suggested in the literature. They have frequently been misdiagnosed as other benign bone lesions. A combination of computed tomography, magnetic resonance imaging and radiography is essential for decreasing misdiagnosis rates. MATERIALS AND METHODS: This retrospective study presents ten cases of intraosseous lipoma. The patients' ages ranged from 25 to 80 years, and six of them were female. Six patients presented with bone pain, whereas four patients were asymptomatic with incidentally discovered lesions. The involved bones were: femur (four patients), tibia (two patients), calcaneus (one patient), sacrum (one patient), iliac bone (one patient), navicular bone (one patient). All of the patients were assessed by means of conventional radiography, computed tomography and magnetic resonance imaging of the affected region. RESULTS: In all of the cases, plain films revealed well-defined lytic lesions. Both computed tomography and magnetic resonance imaging were quite useful in demonstrating fat within the femur. The histologic pattern of all tumors was that of mature adipose tissue. CONCLUSION: Intraosseous lipoma is a well-defined entity that may develop with varying presentations. Plain radiographs alone cannot establish the diagnosis of this lesion. However, both computed tomography and magnetic resonance imaging are quite useful methods in these cases.

Intracortical lipoma of the femur

Intracortical lipoma is an extremely rare benign primary bone tumor. We encountered a case of an intracortical lipoma found incidentally in the femur of a 31-year-old female. Magnetic resonance imaging and computed tomography of the femur demonstrated an intracortical fatty lesion in the posterolateral aspect of the diaphysis. The intracortical lesion showed some intramedullary extension, multiple septations, and dot-like calcifications. Intralesional curettage was performed. Histologically, the tumor consisted of mature, viable adipocytes without foci of fat necrosis or dystrophic calcification.

From the archives of the AFIP: benign musculoskeletal lipomatous lesions

Benign lipomatous lesions involving soft tissue are common musculoskeletal masses that are classified into nine distinct diagnoses: lipoma, lipomatosis, lipomatosis of nerve, lipoblastoma or lipoblastomatosis, angiolipoma, myolipoma of soft tissue, chondroid lipoma, spindle cell lipoma and pleomorphic lipoma, and hibernoma. Soft-tissue lipoma accounts for almost 50% of all soft-tissue tumors. Radiologic evaluation is diagnostic in up to 71% of cases. These lesions are identical to subcutaneous fat on computed tomographic (CT) and magnetic resonance (MR) images and may contain thin septa. Lipomatosis represents a diffuse overgrowth of mature fat affecting either subcutaneous tissue, muscle or nerve, and imaging is needed to evaluate lesion extent. Lipoblastoma is a tumor of immature fat occurring in young children, and imaging features may reveal a mixture of fat and nonadipose tissue. Angiolipoma, myolipoma, and chondroid lipoma are rare lipomatous lesions that are infrequently imaged. Spindle cell and pleomorphic lipoma appear as a subcutaneous lipomatous mass in the posterior neck or shoulder, with frequent nonadipose components. Hibernoma appears as a lipomatous mass with serpentine vascular elements. Benign lipomatous lesions affecting bone, joint, or tendon sheath include intraosseous lipoma, parosteal lipoma, liposclerosing myxofibrous tumor, discrete lipoma of joint or tendon sheath, and lipoma arborescens. Intraosseous and parosteal lipoma have a pathognomonic CT or MR appearance, with fat in the marrow space or on the bone surface, respectively. Liposclerosing myxofibrous tumor is a rare intermixed histologic lesion commonly located in the medullary canal of the intertrochanteric femur. Benign lipomatous lesions may occur focally in a joint or tendon sheath or with diffuse villonodular proliferation in the synovium (lipoma arborescens) and are diagnosed based on location and identification of fat. Understanding the spectrum of appearances of the various benign musculoskeletal lipomatous lesions improves radiologic assessment and is vital for optimal patient management.

MRI findings of intraosseous lipoma: case report

Intraosseous lipoma is one of the rarest benign bone tumors and usually presents in the fourth to fifth decades. Except for minor symptoms, they are usually asymptomatic. Metaphysis of long bones, especially proximal parts of femur and fibula, are involved in most cases. We present intraosseous lipoma to discuss the benefits of MRI and contrast-enhanced MRI findings for differential diagnosis.

Intraosseous lipoma: report of 35 new cases and a review of the literature

OBJECTIVE

To identify the common imaging features of intraosseous lipomas on radiographs, magnetic resonance imaging (MRI) and computed tomography (CT), and review their histological features.

DESIGN AND PATIENTS

Thirty-five previously unreported cases of intraosseous lipoma were reviewed and a meta-analysis was performed of another 110 cases identified from the English language literature.

RESULTS

The mean age at presentation is 43 years. Sex distribution is nearly equal. Lipomas occur most frequently in the lower limb (71% overall), particularly in the os calcis (32%). Other common sites include the metaphyses of long bones, where lesions are typically eccentric. Lipomas are usually well defined, but marginal sclerosis is commoner in lesions of the os calcis (61%) than at other sites (38%). Calcification is also more frequent in the os calcis (62%), and almost invariably centrally located. Calcification at other sites is less common (30%), and is more variable in appearance. Bone expansion is less common (30%), and usually minimal. Fat necrosis and cyst formation identified on MRI is common (67%), and more frequent in the os calcis.

CONCLUSIONS

Although there is correlation between the histological and radiological features of intraosseous lipomas in general, some discrepancies occur in the radiological appearances of lipomas in different sites. The evidence that these lesions are true benign tumours of fat is controversial. Several aetiological factors have been implicated in their development. The constant location of os calcis lesions at the critical angle suggests an aetiology that may be related to biomechanical lines of stress. In other instances it is possible that involution of pre-existing lesions may lead to the development of lipomas.

Radiologic case study. Benign intraosseous lipoma

Intraosseous lipomas are uncommon lesions of bone most often diagnosed incidentally. They typically manifest a classic radiographic appearance, but CT or MRI may be useful in diagnosing lesions that are atypical or incompletely defined radiographically and avoid an unnecessary biopsy.

Intracortical lipoma of the femur

The authors report on a rare case of intracortical lipoma of the right femur in a 74-year-old woman. Magnetic resonance imaging and computed tomography of the femur demonstrated an intracortical lesion in the lateral diaphysis. No medullary involvement by the lesion was noted. Both imaging methods revealed the presence of fat in the lesion. Histologically, the tumor consisted of a large area of mature adipose tissues, admixed with foci of fat necrosis, calcification, and myxoid degeneration. Total excision of the tumor was curative. This is the second reported case of intracortical lipoma.

Intraosseous lipoma of the humeral head: MR appearance

Intraosseous lipoma is the rarest benign primary bone tumor. We report a case of juxtaarticular intraosseous lipoma in the humeral head of a 50-year-old man. Roentgenographic, computed tomographic (CT), magnetic resonance (MR), scintigraphic, and histologic findings of this case are presented.

Subperiosteal lipoma: A case report

Lipomas are the most common benign mesenchymal tumor. They can occur in various locations such as subcutaneous tissue, muscle, nerve, synovium, different periosteal layers, and bone [Diagnosis of bone and joint disorders. 3rd ed. Philadelphia: Saunders, 1995. p. 3814, 3947; Skeletal Radiol 27 (1998) 375]. To our knowledge, however, lipomas arising in a subperiosteal location have not been described previously. We present a patient with two subperiosteal lipomas of the femur.