Benign periarticular, bone and joint lipomatous lesions

Intraosseous myolipoma of the calcaneus

A man in his 40s presented with an incidental finding of an osteolytic bone lesion. He sustained an ankle injury while inline skating, fracturing his lateral malleolus. Besides the fracture, radiographic imaging on the day of the injury incidentally revealed a well-defined solitary osteolytic lesion with a sclerotic rim within the right calcaneus. MRI showed an intraosseous, fat-containing lesion with focal contrast enhancement, assessed as an intraosseous lipoma with central necrosis. In the pathological analysis of a sample of the lesion an intraosseous myolipoma of the calcaneus was found-an unexpected and extraordinary finding. To prevent pathological fracturing, curettage and bone grafting were performed using autologous iliac crest bone in combination with allogenous bone chips.

Intra-articular Fibrolipoma of the Stifle in a Dog

A 12 yr old male castrated miniature Australian shepherd dog presented for surgical consultation of historical bilateral medial patellar luxations with a 3 mo history of an acute onset of a left pelvic limb lameness. Physical examination confirmed medial patellar luxations and a mass effect of the left stifle medially. Radiographs showed medial distension of the joint capsule by a soft tissue opacity. Fine-needle aspirate of the left stifle revealed a mesenchymal cell population. Left medial parapatellar stifle arthrotomy found a fatty mass, which was excised at its base. A benign fibrolipoma was diagnosed on histopathology, and the excision was expected to be curative. The owners reported immediate improvement of perceived comfort postoperatively. At 2 and 24 wk, the dog returned to a normal level of function. Lipomas of the stifle, although rare, should be considered as a differential for intra-articular masses causing lameness.

Bone Tumor Risk Stratification and Management System: A Consensus Guideline from the ACR Bone Reporting and Data System Committee

The assessment and subsequent management of a potentially neoplastic bone lesion seen at diagnostic radiography is often complicated by diagnostic uncertainty and inconsistent management recommendations. Appropriate clinical management should be directed by risk of malignancy. Herein, the ACR-sponsored Bone Reporting and Data System (Bone-RADS) Committee, consisting of academic leaders in the fields of musculoskeletal oncology imaging and orthopedic oncology, presents the novel Bone-RADS scoring system to aid in risk assignment and provide risk-aligned management suggestions. When viewed in the proper clinical context, a newly identified bone lesion can be risk stratified as having very low, low, intermediate, or high risk of malignancy. Radiographic features predictive of risk are reviewed include margination, pattern of periosteal reaction, depth of endosteal erosion, pathological fracture, and extra-osseous soft tissue mass. Other radiographic features predictive of histopathology are also briefly discussed. To apply the Bone-RADS scoring system to a potentially neoplastic bone lesion, radiographic features predictive of risk are each given a point value. Point values are summed to yield a point total, which can be translated to a Bone-RADS score (1-4) with corresponding risk assignment (very low, low, intermediate, high). For each score, evidence-based and best practice consensus management suggestions are outlined. Examples of each Bone-RADS scores are presented, and a standardized diagnostic radiography report template is provided.

A rare case of an intra-articular true lipoma of the ankle

BACKGROUND

Most of the foot and ankle soft tissue tumors are benign. Although lipomas are the most common soft tissue tumors, intra-articular lipomas are an extremely rare entity. The majority of described cases of intra-articular lipomas occur in the knee joint. In particular, an intra-articular true lipoma of the ankle has not been reported.

CASE PRESENTATION

We report the case of a 45-year-old woman who presented with a progressively growing ankle mass over 5 years, which started to restrict the range of motion. It was not preceded by any trauma or sports activity. On examination, a non-tender firm mass was evident on the lateral aspect of the right ankle joint with no signs of inflammation. It was non-compressible, non-mobile, and did not transilluminate. The clinical diagnosis was probable for a soft tissue ganglion. A radiograph revealed a soft tissue opacity over the anterolateral aspect of the tibiotalar joint. Magnetic resonance imaging (MRI) demonstrated a well-defined, multilobulated, encapsulated lesion located at the lateral aspect of the tibiotalar joint; with intra- and extra-articular components and an analogous signal intensity to fat. The patient underwent surgical excision of the tumor, and the histopathological examination showed mature adipose tissue representing an intra-articular lipoma. At the follow-up visit, the patient had complete resolution of symptoms and no active complaints.

CONCLUSION

An intra-articular true lipoma of the ankle is an extremely rare tumor. MRI is an invaluable diagnostic tool to make a reliable diagnosis of intra-articular masses.

Liposclerosing myxofibrous tumor of the distal femur: A case report

Introduction

Liposclerosing myxofibrous tumor (LSMFT) is a rare benign fibro-osseous tumor that most frequently occurs in the proximal femur. The reported literature shows that the proximal femur, ilium, tibia, humerus, rib, and skull have occurred, but so far, the female distal femur has not been characterized in detail. This, we think, is the first single comprehensive case report of the female distal femur. To prevent misdiagnosis and overtreatment of this illness, it is critical for us to continue strengthening our knowledge of it and to add it to the differential diagnosis of the space-occupying lesion of the female distal femur.

Case summary

Two months ago, a 55-year-old female patient was found to have a space-occupying lesion of the left distal femur and the pain symptom was aggravated. She underwent thorough curettage and bone grafting without additional treatment to relieve the current symptoms and determine the nature of the lesion in our hospital. The intraoperative specimens were submitted to the pathology laboratory for analysis, and the result was reported as LSMFT. And six months after the operation, the patient returned to our hospital for another x-ray examination and we found that she had recovered well without any signs of recurrence. The patient self-reported that she had now resumed her daily life without any uncomfortable symptoms.

Conclusion

The incidence of LSMFT itself is relatively low, and the occurrence of the distal femur is even rarer. However, it is recommended to add LSMFT into the differential diagnosis of the occupying lesions of the distal femur. Once the diagnosis is made, thorough curettage and bone grafting without additional special treatment can achieve better postoperative outcomes. The patient gave her agreement after learning that information about the case will be submitted for publication.

A Rare Presentation of a True Intra-articular Lipoma: A Case Report and Review of Imaging Findings

This report describes the unique case of an intra-articular lipoma in a 34-year-old male. The patient presented with a history of chronic knee pain associated with an intermittent sensation of the knee giving way. Physical examination and initial radiographic imaging were unremarkable. Magnetic resonance imaging (MRI) revealed a 9.2 x 6.7 mm ovoid mass posterior to the posterior cruciate ligament (PCL) exhibiting hyperintense signals on T1-weighted images and intermediate-to-high intensity signals on T2. On subsequent proton density fat suppression sequences, the mass demonstrated homogenous signal suppression and was confirmed as being a lipoma. To the best of our knowledge, this is only the second reported case of an intra-articular lipoma arising posterior to the PCL. Intra-articular lipomas, albeit rare, should be considered in the differential diagnosis for chronic knee pain with associated joint motion abnormalities. MRI remains the gold standard in imaging intra-articular soft tissue pathology and should be the study of choice in differentiating intra-articular lipomas from similar conditions such as pigmented villonodular synovitis and lipoma arborescens.

Intra-articular Lipoma of the Knee Joint Located in the Lateral Recess: A Case Report

Introduction:

Lipomas are the most common type of soft-tissue tumor, but intra-articular lipomas are very rare. Most cases occur in the knee joint. This is a report of intra-articular lipoma in the knee joint, 8 months after removal with good post-operative outcome.

Case Report:

A 56-year-old female who presented soft-tissue mass on her right knee. She felt uncomfortable but not in pain. The mass grew gradually and she wanted to be surgically removed. The mass was too large (5 cm × 4 cm × 2 cm) to be removed endoscopically, so arthrotomy was made. The mass was true lipoma histologically. She is living happily without recurrence after surgery.

Conclusion:

We have described an intra-articular synovial lipoma in the knee of a middle-aged female. Intra-articular lipomas are very rare. The tumor in this case was relatively large but painless, and the chief complaint was discomfort. It grew gradually, so the removal was performed. At present, the patient is living happy without recurrence after surgery.

Large intra-articular true lipoma of the knee

BACKGROUND

Intra-articular lipomas are rare and very few cases have been reported in the knee. To the best of our knowledge, here we report the largest lipoma to have ever been observed in the knee. It is crucial to avoid the misdiagnose of lipoma arborescens, which is associated with degenerative joint disease. Lipoma is a homogeneous, ovoid, adipose tissue tumor that is contained within a fibrous capsule and not associated with previous disease.

CASE PRESENTATION

A 48-year-old male, with a soft-tissue tumor on the superomedial aspect of the right knee. Magnetic resonance imaging (MRI) revealed an intra-articular lipoma. The mass was resected by means of a limited arthrotomy.

CONCLUSIONS

Knee lipoma is an extremely rare disease that must be diagnosed by MRI. Where possible, it should be resolved by arthroscopic resection.

Synovial Lipomatosis with Chondroblastoma in an 8-year-old Female: A Previously Unreported Entity

Introduction:

Synovial lipomatosis is a rare disease entity and a very small number of cases have been reported so far. It is characterized by villous proliferation of the synovium with expansion by mature adipose tissue. The etiology is unclear, thought cases can be seen secondary to injury, inflammation, chronic degenerative changes and neoplasms. Etiopathogenesis is still unclear, however is seen secondary to injury, inflammation, chronic degenerative conditions and neoplasms.

Case Report:

An 8-year-old female child presented with pain and swelling in the left knee. Radiological examination suggested of a lytic lesion in upper tibia along with reactive synovial thickening. The lytic lesion was excised and an incisional biopsy was taken from the hyperplastic synovium. Histopathological examination of the synovial tissue showed villi-like structures with mature adipose tissue expanding the synovial lining along with the presence of mild chronic inflammatory cell infiltrate. The lytic lesion showed a cartilaginous tumor comprising mineralized chicken wire matrix surrounding the chondroblasts. A final diagnosis of synovial lipomatosis with chondroblastoma was made on histopathological examination.

Conclusion:

This may be the first case report in medical literature of synovial lipomatosis coexisting with chondroblastoma in an adolescent girl. It also highlights the need for its increased awareness among young radiologists and pathologists so that an early diagnosis directs correct management and prevents further joint morbidity.