From the archives of the AFIP: benign musculoskeletal lipomatous lesions

Giant parosteal lipoma of thigh: A case report and review of the literature

INTRODUCTION AND IMPORTANCE

Parosteal lipoma is an uncommon benign tumor that can arise in various parts of the body. Giant parosteal lipomas are particularly rare and may compress or interfere with adjacent structures. Effective management typically involves surgical removal, with a thorough evaluation to exclude the possibility of malignancy.

CASE PRESENTATION

We describe a case of a patient presenting with a soft tissue mass in the thigh measuring 10 cm × 14 cm × 26 cm and weighing 1300 g. MRI findings were suggestive of a parosteal lipoma. Wide excision of the tumor was performed using an anterior thigh approach. Histopathological examination confirmed the diagnosis of parosteal lipoma. The postoperative course was uneventful, with no complications or local recurrence observed.

CLINICAL DISCUSSION

Most lipomas are asymptomatic; however, in some cases, they can affect nearby structures, potentially leading to compression syndromes. MRI is the preferred imaging technique for evaluating large soft tissue tumors with suspected malignancy. It plays a crucial role in distinguishing between differential diagnoses and facilitating treatment planning. Surgery is recommended for tumors that are large, symptomatic, compress vital structures like nerves or blood vessels, or are suspected to be malignant. Performing a wide tumor excision is crucial to reduce the likelihood of recurrence.

CONCLUSION

Malignancy should be carefully ruled out in diagnosing giant parosteal lipoma. MRI plays a crucial role in distinguishing between potential diagnoses, and aiding in surgical planning. Complete tumor excision through wide resection is the treatment of choice for this lesion.

Macrodystrophia Lipomatosa Involving Both Median and Tibial Nerves: A Two-Case Series

Macrodystrophia lipomatosa (MDL) is a rare congenital disorder marked by excessive proliferation of mesenchymal tissues, predominantly adipose tissue, which often manifests in the upper extremities (particularly the median nerve) and less frequently in the lower extremities (such as the tibial nerve). When MDL affects peripheral nerves, it is commonly associated with fibrolipomatous hamartoma (FLH), a benign fibrofatty overgrowth. The MRI is central to diagnosing MDL, as it provides critical visualization of pathological fat infiltration within the enlarged nerve. We present two cases illustrating the MRI characteristics of MDL in both the median and tibial nerves. Recognizing these hallmark radiological features is essential for accurate diagnosis, differentiation from other neuropathies, and informed management.

Development of Multiple Subcutaneous Lipomas After Six Months of Hormone Replacement Therapy: A Case Report

Lipomas are common benign soft tissue tumors composed of mature adipocytes, typically presenting as slow-growing, painless subcutaneous nodules. While the underlying etiology remains unclear, various factors have been proposed as potential contributors. In some individuals, multiple subcutaneous lipomas can develop, and their occurrence has been considered in relation to systemic conditions or familial predisposition. Hormone replacement therapy (HRT), commonly used for menopausal symptom management, influences lipid metabolism and angiogenesis through hormonal signaling pathways; however, its potential role in lipoma formation remains uncertain. Herein, we present a case of a 57-year-old woman who developed multiple subcutaneous lipomas on the thighs and buttocks after initiating HRT. This case highlights a possible association between hormonal changes and lipoma formation, emphasizing the importance of further research into the mechanisms underlying adipose tissue growth.

Role of MRI and surgical excision in long-standing diffuse-type GCTTS of the flexor tendon sheath

Diffuse-type giant cell tumor of the tendon sheath (GCTTS) is a rare, benign, yet locally aggressive soft tissue tumor commonly affecting the hand. This case report presents a 55-year-old male with a 5-year history of GCTTS in the flexor tendon sheath of the long finger. MRI played a critical role in both diagnosis and surgical planning, revealing key features such as the tumor's 10 cm length, hemosiderin deposition, and blooming artifacts. The patient underwent successful surgical excision with no recurrence at the 1-year follow-up. This case underscores the significance of MRI in preventing functional impairment and reducing recurrence risk in diffuse-type GCTTS.

A pictorial review of osseous and cartilaginous soft tissue tumours

Osseous and cartilaginous soft tissue tumours are a heterogenous group of neoplasms characterised by the presence of an osseous or cartilaginous component. Mineralisation of the osseous or cartilaginous component is a common finding amongst these lesions, presenting as calcification/ossification on radiological imaging. This pictorial review examines the key imaging findings and characteristics of osseous and cartilaginous soft tissue tumours with a focus on the distinguishing features which can help the radiologist to differentiate benign and malignant lesions. All examples provided are of histopathologically proven cases seen in our tertiary referral soft tissue sarcoma centre.

Para-articular and intra-articular soft tissue lesions: Radiologic-pathologic correlation

Articular masses comprise various disease entities including benign or malignant proliferative processes and other non-neoplastic processes such as infection, deposition diseases, vascular malformations, and other lesions. Many diseases that lead to intra-articular or para-articular masses have distinct imaging features, particularly on MRI. Radiologists can localize masses to the joint space by knowing the articular anatomy and can reach a suggested diagnosis by looking at precise imaging findings. In this review article, we first define the concept of articular space (intraarticular, para-articular) and the normal joint anatomy and histology. We provide a general and comprehensive approach for evaluation of articular lesions on MRI. We then describe specific imaging and histologic features of typical benign and malignant soft tissue articular neoplasms and some non-neoplastic mimickers; and provide a radio-pathologic correlation of the different described entities.

Use of radiologic imaging to differentiate lipoma from atypical lipomatous tumor/well-differentiated liposarcoma: Systematic review

Background

Lipomas and atypical lipomatous tumors or well-differentiated liposarcomas (ALTs/WDLs), pose a diagnostic challenge due to their overlapping clinical and imaging features. Accurate differentiation is crucial as treatment strategies differ significantly between benign lipomas and malignant ALTs/WDLs. In recent years, medical imaging techniques have shown promise in distinguishing lipomas from ALTs/WDLs by providing enhanced visualization and assessment of various imaging parameters.

Objective

This systematic review aimed to investigate the use of magnetic resonance (MR) imaging and computed tomography (CT) scan to differentiate lipomas from ALTs/WDLs.

Methods

A systematic review was conducted by using MEDLINE, PubMed, PubMed Central, Cochrane Library, Google Scholar, and clinical trail.gov to identify imaging studies published between 2001 and 2022. Two independent reviewers reviewed 221 record to scrutinize the studies. The methodological quality of each included studies was assessed the using Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool.

Results

Thirteen retrospective cohort studies included 1,390 of total patients. Among them, 11 studies used MR imaging, 2 studies used CT scan and MR imaging both to differentiate lipoma from ALTs/WDLs. The significant diagnostic variables identified in the included studies were age, size, texture, mean intensity, contrast enhancement, location, septation, and nodularity. The overall, sensitivity, specificity, and accuracy of the included studies for diagnosis of lesions range from 66% to 100%, 37% to 100%, and 76% to 95%, respectively. The positive and negative predictive values range from 46.9% to 90% and 86% to 100%, respectively.

Conclusion

The most frequent diagnostic features of ALTs/ WDLs include tumors ⩾110 mm in size, often in patients over 60, predominantly in the lower extremities, with an irregular shape, incomplete fat suppression, contrast enhancement, nodularity, septation >2 mm, and predictive markers such as lactate dehydrogenase >220 and a short tau inversion recovery-signal intensity ratio >1.18.

Lipoma in uncommon site: A case report of finger lipoma from Nepal

INTRODUCTION

Lipomas are the most common benign mesenchymal tumors, making up 50 % of soft tissue tumors. However, while they frequently occur in areas like the head, neck, shoulders, and back, lipomas in the hands and wrists are rare, particularly in the fingers where they are exceptionally uncommon.

CASE PRESENTATION

We present a case of 62-year-old female presented with a six-year history of a gradually enlarging, painful swelling on the palmar aspect at the base of her left index finger. Examination revealed a soft, fluctuating, 3 cm × 2 cm swelling. USG and MRI suspected it to be a lipoma. The lesion was excised, and histopathology confirmed a benign lipoma.

DISCUSSION

Lipomas, derived from mesenchymal preadipocytes, often have genetic and metabolic links, including in individuals with obesity, hyperlipidemia, and diabetes. While typically asymptomatic, lipomas in the hands and fingers can cause pain and impairment, necessitating surgical resection. Accurate diagnosis may require imaging, and treatment yields favourable outcomes with low recurrence rates.

CONCLUSION

Despite their rarity, lipomas in the hands and fingers should be considered when evaluating non-discharging swellings. Surgical resection is the primary treatment.

Rare case of thigh lipoblastoma in an infant: A case report

INTRODUCTION AND IMPORTANCE

Lipoblastoma is a rare, benign tumor that primarily affects infants and young children, representing a small percentage of soft tissue tumors in this population. Its early diagnosis and surgical management are crucial for favorable outcomes, as lipoblastoma can lead to significant complications if left untreated.

CASE PRESENTATION

We report the case of an 18-month-old female toddler who presented with a progressively growing, painless mass in the left medial thigh, which had developed over six months. Imaging studies, including CT and MRI, revealed a well-defined, hypodense lobulated mass consistent with lipoblastoma. Surgical excision was performed, and the mass measured approximately 7 by 6 cm. Histopathological examination confirmed the diagnosis of lipoblastoma. The patient experienced a successful recovery without recurrence during a one-year follow-up period.

DISCUSSION

Lipoblastoma typically presents as a painless subcutaneous soft tissue mass that progressively grows. Symptoms often relate to the tumor's location and size or the mass effect on surrounding structures. Imaging studies, particularly CT and MRI, play a crucial role in making a presumptive diagnosis by revealing the tumor's characteristics and components. Total excision remains the treatment of choice for lipoblastoma.

CONCLUSION

Lipoblastoma should be included in the differential diagnosis of rapidly growing, painless masses in children under three years of age. The treatment of choice is complete surgical resection of the tumor, which is crucial for achieving favorable outcomes and reducing recurrence risk.

A large thigh hibernoma in a 23-years-old man: Case report

INTRODUCTION AND IMPORTANCE

Hibernomas are benign soft tissue tumors containing prominent brown adipocytes that resemble normal brown fat, they occur in a wide age range (from 2 to 75 years) and make up for about 1 % of all adipocytic tumors <2 % of benign fatty neoplasms. They have traditionally been regarded as benign tumors with no potential for malignancy; due to their similarity in clinical and radiographical presentation, they are often misdiagnosed as malignant tumors like liposarcomas. While these tumors are generally considered non-malignant, their distinctive characteristics and uncommon occurrence make them an intriguing subject for medical study.

CASE PRESENTATION

This article describes the clinical, radiographic, and histologic features of a young patient with a thigh hibernoma compressing the obturator nerve.

CLINICAL DISCUSSION

Hibernomas are more likely to develop in brown fat-enriched areas in newborns, such as the neck, scapular area, armpit, chest, and retroperitoneum. Increased awareness among clinicians and pathologists, coupled with advances in imaging and immunohistochemistry, has enhanced our ability to accurately identify and treat these intriguing tumors.

CONCLUSION

The rarity of hibernomas together with the close resemblance of their radiological features to those of malignant tumors like liposarcomas or atypical lipomatous tumors, make these lesions extremely difficult to identify and often misdiagnosed. Continued research is essential to further our understanding this neoplasm and refine diagnostic and therapeutic approaches.

A case of lipoblastoma in a pediatric patient

Lipoblastoma is a benign soft tissue tumor that originates from embryonic white fat. Lipoblastoma presents as a slow-growing mass that commonly occurs in the extremities of young children. Histological examination remains the gold standard in confirming lipoblastoma; however, radiology examination can help identify and evaluate the extent and characterization of the mass prior to the excision. Here, we report a 7-year-old male patient who presented with a painless mass in the right popliteal extending to the proximal cruris areas, and the imaging modalities suggested the presence of fat within the mass. The patient then underwent complete excision, and histopathology examination revealed lipoblastoma. This study highlights the possibility of lipoblastoma in older children and the role of imaging examinations in the diagnosis.

Pathology of intra-articular tumours and tumour-like lesions: pearls, pitfalls and rarities from a general surgical pathology practice

Intra-articular tumours are uncommonly encountered in routine practice and may present diagnostic challenges to pathologists. Challenges unique to this site include distinction from more common reactive synovial conditions, which are far more common; histologic variability; superimposed reactive changes; and often, lack of provided clinicoradiological context. This article reviews the pathology of the synovial tumours and tumour-like lesions, including diagnostic pearls, pitfalls and rare entities.

Atypical Intramuscular Lipoma of the Tongue. Case Report

Although they are frequently benign tumors of mesenchymal origin, lipomas sporadically develop in the oral cavity. Intramuscular lipomas, which originate inside muscles, are a rare subtype. When found in the tongue, they are considerably more uncommon and its etiology remains unclear. Histological examination of the specimen shows mature adipocytes of uniform size with minimal vascularization and sometimes striated muscle fibers are to be seen in the periphery. A yellowish submucosal mass that is slowly expanding, painless, and asymptomatic, is typically seen based on a patient's history and clinical examination. Lipomas that occur in uncommon locations should be mentioned and should be considered in the differential diagnosis of an oral mass. The main treatment option is a complete surgical excision. The purpose of this report is to describe a case of a 43-year-old female patient with an atypical, well-defined intramuscular lipoma in her tongue that began to form around 10 months ago.

Deep-seated intermuscular lipoma of posterior neck muscles: a case report and review of literature

Lipomas are the most common soft tissue tumours, accounting for nearly 50% of all soft tissue neoplasms. Among the types of lipomas, intermuscular lipomas are rare. We report the case of a 46-year-old man with a deep-seated lipoma located between the trapezius and splenius capitis muscles in the posterior neck triangle. A successful surgical excision was performed. This case highlights challenges in diagnosis, surgical management, and the importance of complete excision in minimizing the risk of recurrence. This type of lipoma remains relatively understudied; therefore, further studies are needed to increase awareness of its incidence, clinical presentation, diagnostic evaluation, and optimal management.

Case report: a case report of excision of giant lipoma in the posterior neck

Lipomas, benign tumors originating from the anomalous proliferation of adipocytes, predominantly emerge in regions rich in adipose tissue. However, their presence in the head and neck areas remains rare, constituting approximately 13% of all diagnosed lipoma cases. This study presents a case involving a substantial subcutaneous lipoma located at the posterior neck, measuring about 20 cm × 19 cm × 10 cm. The patient presented with swelling and pain in the back of the neck. And the considerable dimensions of this lipoma significantly impacted the patient's quality of life and aesthetic appearance. Concurrently, the patient exhibited symptoms indicative of degenerative cervical spine disease and cervical disc herniation. After admission, a comprehensive examination, including ultrasound, CT scan, and MRI, was conducted. Given the clinical complexity, the decision for surgical intervention was deemed essential. The surgical strategy entailed a meticulous total excision of the tumor through an incision made in the posterior cross-neck, coupled with the strategic removal of excess skin. To facilitate wound healing, postoperative management included the use of negative pressure drainage. Pathological examination conclusively identified the mass as a lipoma. Postoperative follow-ups indicated successful recovery, as evidenced by the restoration of the neck's aesthetic contour and the complete resolution of the previously observed restrictions in sagittal neck movement.

Intraosseous Lipoma of Calcaneus An Uncommon Cause of Heel Pain: A Case Report

ABSTRACT

Intraosseous lipoma of calcaneum is a rare cause of heel pain. Calcaneum is a typical site of involvement of IOL. There are only a few published articles regarding calcaneal intraosseous lipoma and one has been reported from Nepal. We report a case of 35 years female who presented with left heel pain for 1 year. The pain was gradually increasing in intensity and was severe enough to refrain her from activities of daily living. She was surgically operated with curettage and filling the defect with bone cement. There is no residual pain at 2.5 years follow up. We briefly review the postulated pathogenesis, clinical manifestations, diagnosis and various modalities of treatment of intraosseous lipoma. An orthopedic surgeon should have high degree of suspicion regarding the uncommon cause of heel pain and its possible management. When conservative methods do not relieve symptoms, surgical excision and filling the defect with bone cement provides long term relief.

Osteochondrolipoma of the foot treated by surgical excision: a case report and literature review

BACKGROUND

Osteochondromas, classified as a new benign subtype of lipomas and characterised by chondroid and osseous differentiation, are rare lesions that have been infrequently reported in previous literature. The maxillofacial region was reported as the most frequent localization, with infrequent occurrence in the lower limb. This paper represents the first documented case report of osteochondrolipoma in the foot.

CASE PRESENTATION

A 51-year-old male patient presented with a chief complaint of right foot pain at the plantar aspect, accompanied by the observation of swelling between the first and the second metatarsal shafts. His complaint of pain and swelling started 10 and 4 years prior, respectively. Since their onset, both symptoms have progressed in nature. Imaging revealved a large mass exhibiting a nonhomogenous composition of fibrous tissue and bony structures. Surgical intervention through total excision was indicated.

CONCLUSION

Osteochodrolipoma is a benign lesion that can affect the foot leading to decreased functionality of the foot due to the pain and swelling. Surgical excision is the recommended approach for this lesion, providing both symptomatic relief and confirmation of the diagnosis through histopathological examination.

Giant retroperitoneal myolipoma mimicking liposarcoma: report of a resected case and review of the literature

Myolipomas are rare tumors that are often difficult to differentiate from liposarcoma. Herein, we report a case of resected giant myolipoma preoperatively diagnosed as liposarcoma. A 63-year-old woman was suspected of having a large retroperitoneal liposarcoma on October 202X. The patient was referred to our department for tumor resection and a histological diagnosis. After consultation with the urology, obstetric and gynecology, and vascular surgery departments, tumor resection was planned, including the potential resection of other organs. Intraoperative findings revealed a large, elastic, soft tumor with a smooth surface and a capsule occupying the entire abdominal cavity. The tumor was adherent to the stomach, left colon, and uterine adnexa, and no invasion was observed. The tumor was completely resected, and organ resection was not necessary. The tumor was 40 cm in diameter and 4.0 kg in weight. Pathological examination and immunostaining confirmed a diagnosis of myolipoma. The patient's postoperative course was uneventful, and she was discharged on postoperative day 10 with no complications. Twelve months after surgery, the patient was doing well. To the best of our knowledge, we report a complete resection of the largest retroperitoneal myolipoma reported to date. Physicians should consider surgery, even for suspected large sarcomas that may be difficult to resect completely.

Desmoid Fibromatosis Fused With a Lipoma in the Upper Arm

Lipoma, the most common mesenchymal tumor, often appears as a slow-growing mass in the musculoskeletal system (MSK). While generally non-invasive, their location can cause symptoms. Desmoid fibromatosis (DF), a rare and locally aggressive neoplasm, poses challenges in MSK system diagnosis and management due to its infiltrative nature. Despite lacking metastatic potential, DF has a high recurrence rate, classifying it as "intermediate, locally aggressive" in the WHO classification. Collaborative efforts among orthopedic surgeons, radiologists, and pathologists are crucial for accurate diagnosis and treatment planning for all tumors of the MSK system. This case report presents the first documented example of a DF within a lipoma, highlighting the challenges of diagnosing and treating musculoskeletal tumors.

Infiltrative Intramuscular Lipoma with Overlying Fascial Defect in the Anterior Thigh: A Case Report

This case report details a unique presentation of an infiltrative intramuscular lipoma in the anterior thigh of a 51-year-old female with an overlying fascial defect. The patient reported a progressively enlarging left thigh mass associated with pain exacerbated by knee movement and exercise. MRI revealed a homogeneous intramuscular lipoma without contrast enhancement with a fascial defect. An 8 cm longitudinal incision exposed a 7 x 4 cm fascial defect overlying the lipomatous mass within the rectus femoris muscle. Pathological analysis confirmed an intramuscular lipoma without malignancy. Follow-ups at two, six, and 12 weeks demonstrated pain resolution and no soft tissue bulge. This case underscores the importance of distinguishing intramuscular lipomas from other neoplasms, such as lipomatosis and liposarcomas. The association of a fascial defect with intramuscular lipomas is unprecedented and may be due to the increased pressure on the fascia by the lipoma. The report emphasizes the role of MRI in diagnosis and appropriate surgical management, and highlights the need for further exploration into the etiology of fascial defects associated with intramuscular lipomas.

Parosteal Lipoma

Teaching Point: Recognizing the distinct imaging features of parosteal lipoma.

[Giant cervical lipoma adjacent to carotid artery: a case report and literature review]

BACKGROUND

Cervical lipomas accompanied by neurovascular compression are extremely rare and require surgical treatment in case of appropriate symptoms. The preferable method is gross total resection, as otherwise they tend to recur. Invasive growth is not typical for lipomas. However, large tumors can involve adjacent nerves and vessels and significantly complicate resection.

MATERIAL AND METHODS

We present a 57-year-old patient who underwent resection of giant soft tissue cervical lipoma invading neurovascular bundle and compressing the oropharynx and esophagus with dysphagia and positional asphyxia. The patient was followed-up for previous 5 years. Resection was necessary due to tumor enlargement with appropriate symptoms. Searching for literature data was performed in the Pubmed, Medline, EMBASE, Cochrane Library and eLibrary databases.

RESULTS AND DISCUSSION

Gross total resection of 7-cm tumor was accompanied by mobilization of hypoglossal and vagus nerves, common, external and internal carotid arteries and jugular vein with repositioning of the oropharynx and esophagus. There was mild Horner's syndrome in early postoperative period. The patient was discharged in 4 days after surgery with regression of complaints. We found only 5 reports describing giant cervical lipomas invading neurovascular bundle.

CONCLUSION

Giant cervical lipomas are extremely rare, and total resection with preservation of critical structures is possible in a specialized hospital.

Prognostic value of clinical and MRI features in the screening of lipomatous lesions

BACKGROUND AND OBJECTIVES

Differentiation of lipomatous tumors mostly requires diagnostic biopsy but is essential to decide for the most adequate therapy. This study aims to investigate the prognostic value of available clinical and radiological features with regard to malignancy of the lesion, recurrence and survival.

METHODS

In this retrospective cohort study, 104 patients with a biopsy-proven lipomatous tumor between 2010 and 2015 and a minimum clinical follow-up of two years were enrolled. Next to clinical features (age, gender, location of the lesion, histopathologic diagnosis, stage of disease, time to recurrence and death), MRI parameters were recorded retrospectively and blinded to the histological diagnosis.

RESULTS

Malignant lipomatous tumors were associated with location in the lower extremities and MRI features like thick septation (>2 mm), presence of a non-adipose mass, foci of high T2/STIR signal and contrast agent enhancement. A non-adipose mass was a predictor for recurrence and inferior overall survival, while lesions with high T2/STIR signal showed higher risk of recurrence only. In combination, clinical and radiological features (lower extremities, septation > 2 mm, existence of non-adipose mass, contrast enhancement, and foci of high T2/STIR signal) predicted a malignant lipomatous tumor with an accuracy of 0.941 (95% CI of 0.899-0.983; 87% sensitivity, 86% specificity).

CONCLUSION

Localization and characteristic MR features predict malignancy in most lipomatous lesions. Non-adipose masses are a poor prognostic factor, being associated with tumor recurrence and disease-related death.

Multimodality imaging features of parosteal lipomas

OBJECTIVE

To examine the multimodality imaging characteristics of parosteal lipomas.

MATERIALS AND METHODS

With IRB approval, our institutional imaging database and medical record were retrospectively reviewed from 1990-2020 for cases of pathologically-proven and/or imaging diagnosed parosteal lipomas.

RESULTS

There were 22 patients (12 males, 10 females) with a mean age of 57.1 ± 12.7 years (range 31-80 years). 11/22 cases (50%) were pathologically-confirmed on biopsy or surgical resection and 11/22 (50%) had imaging features compatible with parosteal lipoma. Lesions occurred most commonly along the femur (8/22, 36%), followed by the forearm (3/22, 14%). All cases demonstrated a juxtacortical fatty mass containing an osseous excrescence that was firmly attached to the cortical surface. The osseous excrescences were characterized as pedunculated in 16/22 (73%) and sessile in 6/22 (27%). The average largest dimension of the osseus excrescences was 2.4 ± 1.6 cm (range 0.8-6.1 cm) and the lipomatous portions 7.8 ± 3.8 cm (range 2.0-19.5 cm). The excrescences contained mature bone in 12/22 (55%) cases and a mixture of mature bone and radiating bone spicules in 10/22 (45%). There were non-lipomatous elements in the fatty portion of the mass in 13/22 (59%) of cases. Most cases (19/22, 85%) had cortical thickening/periostitis near the base of the osseous stalk. Two patients had a bone scan that demonstrated uptake in the osseous excrescence, and two patients had an FDG PET/CT that demonstrated no uptake.

CONCLUSION

Parosteal lipomas are a rare benign lipomatous tumor with pathognomonic multimodality imaging features that may obviate the need for biopsy.

Evaluation of Bone and Soft Tissue Tumors of the Shoulder Girdle

INTRODUCTION

The shoulder girdle comprises the scapula, clavicle, proximal humerus, and the soft tissues surrounding these structures. Bone and soft tissue tumors are notably more prevalent in the lower extremity than in the upper extremity. However, the shoulder ranks as the third most common site for primary tumors, following the hip-pelvis and knee.

MATERIALS AND METHODS

This study conducted a retrospective examination of patients who presented with pain and swelling in the shoulder and its vicinity. The evaluation was carried out using a multidisciplinary approach by the Bone and Soft Tissue Tumors Council.

RESULTS

The study included 224 patients diagnosed with a tumoral lesion in the shoulder girdle between 2004 and 2021. Among these patients, 22 were assessed to have lesions other than tumors, while 105 (51.98%) had benign lesions, and 97 had malignant lesions. The most prevalent benign lesions were cystic bone lesions (30) and soft tissue lipomas (10). The primary form of malignant lesion was metastatic tumors (49).

CONCLUSION

Pathologies in the shoulder girdle may manifest through pain, palpable swelling, pathological fractures, or may be incidentally detected via radiological imaging. Notably, pain, hypercalcemia, and pathological fractures are significant indicators, especially in cases of bone metastases, which often follow a highly fatal course when involving long bones. The musculoskeletal system is the third most common site for metastasis, following the lungs and liver. Hence, particular attention should be directed toward metastatic concerns in the shoulder and its surrounding area.

Recommendations for the Management of Incidental Musculoskeletal Findings on MRI and CT

The Canadian Association of Radiologists (CAR) Incidental Findings Working Group consists of both academic subspeciality and general radiologists tasked with either adapting American College of Radiology (ACR) guidelines to meet the needs of Canadian radiologists or authoring new guidelines where appropriate. In this case, entirely new guidelines to deal with incidental musculoskeletal findings that may be encountered on thoracoabdominal computed tomography or magnetic resonance imaging were drafted, focussing on which findings should prompt recommendations for further workup. These recommendations discuss how to deal with incidental marrow changes, focal bone lesions, abnormalities of the pubic symphysis and sacroiliac joints, fatty soft tissue masses, manifestations of renal osteodystrophy and finally discuss opportunistic osteoporosis evaluation.

Aggressive intraosseous lipoma of the scapula: A case report

The details of the pathogenesis of intraosseous lipomas are not fully elucidated, although most cases do not require surgical treatment. The present report describes the case of a 79-year-old female patient diagnosed with intracapsular lipoma who also exhibited an extraosseous extension. Chest computed tomography revealed an abnormal shadow or a mass in the right scapula and destruction of the glenoid bone. Magnetic resonance imaging revealed a high-intensity mass on T1-weighted and T2-weighted images in the same area. Marginal resection of the mass was performed. The histopathology confirmed that the mass was a lipoma. No postoperative recurrence was observed. Oncologists must be aware that lipoma arising within the scapula may extend outside the bone.

Understanding a mass in the paraspinal region: an anatomical approach

The paraspinal region encompasses all tissues around the spine. The regional anatomy is complex and includes the paraspinal muscles, spinal nerves, sympathetic chains, Batson's venous plexus and a rich arterial network. A wide variety of pathologies can occur in the paraspinal region, originating either from paraspinal soft tissues or the vertebral column. The most common paraspinal benign neoplasms include lipomas, fibroblastic tumours and benign peripheral nerve sheath tumours. Tumour-like masses such as haematomas, extramedullary haematopoiesis or abscesses should be considered in patients with suggestive medical histories. Malignant neoplasms are less frequent than benign processes and include liposarcomas and undifferentiated sarcomas. Secondary and primary spinal tumours may present as midline expansile soft tissue masses invading the adjacent paraspinal region. Knowledge of the anatomy of the paraspinal region is of major importance since it allows understanding of the complex locoregional tumour spread that can occur via many adipose corridors, haematogenous pathways and direct contact. Paraspinal tumours can extend into other anatomical regions, such as the retroperitoneum, pleura, posterior mediastinum, intercostal space or extradural neural axis compartment. Imaging plays a crucial role in formulating a hypothesis regarding the aetiology of the mass and tumour staging, which informs preoperative planning. Understanding the complex relationship between the different elements and the imaging features of common paraspinal masses is fundamental to achieving a correct diagnosis and adequate patient management. This review gives an overview of the anatomy of the paraspinal region and describes imaging features of the main tumours and tumour-like lesions that occur in the region.

Increasing differential diagnosis between lipoma and liposarcoma through radiomics: a narrative review

Soft tissue sarcomas (STSs) are rare, heterogeneous, and very often asymptomatic diseases. Their diagnosis is fundamental, as is the identification of the degree of malignancy, which may be high, medium, or low. The Italian Medical Oncology Association and European Society of Medical Oncology (ESMO) guidelines recommend magnetic resonance imaging (MRI) because the clinical examination is typically ineffective. The diagnosis of these rare diseases with artificial intelligence (AI) techniques presents reduced datasets and therefore less robust methods. However, the combination of AI techniques with radiomics may be a new angle in diagnosing rare diseases such as STSs. Results obtained are promising within the literature, not only for the performance but also for the explicability of the data. In fact, one can make tumor classification, site localization, and prediction of the risk of developing metastasis. Thanks to the synergy between computer scientists and radiologists, linking numerical features to radiological evidence with excellent performance could be a new step forward for the diagnosis of rare diseases.

MRI radiomics-based machine learning for classification of deep-seated lipoma and atypical lipomatous tumor of the extremities

PURPOSE

To determine diagnostic performance of MRI radiomics-based machine learning for classification of deep-seated lipoma and atypical lipomatous tumor (ALT) of the extremities.

MATERIAL AND METHODS

This retrospective study was performed at three tertiary sarcoma centers and included 150 patients with surgically treated and histology-proven lesions. The training-validation cohort consisted of 114 patients from centers 1 and 2 (n = 64 lipoma, n = 50 ALT). The external test cohort consisted of 36 patients from center 3 (n = 24 lipoma, n = 12 ALT). 3D segmentation was manually performed on T1- and T2-weighted MRI. After extraction and selection of radiomic features, three machine learning classifiers were trained and validated using nested fivefold cross-validation. The best-performing classifier according to previous analysis was evaluated and compared to an experienced musculoskeletal radiologist in the external test cohort.

RESULTS

Eight features passed feature selection and were incorporated into the machine learning models. After training and validation (74% ROC-AUC), the best-performing classifier (Random Forest) showed 92% sensitivity and 33% specificity in the external test cohort with no statistical difference compared to the radiologist (p = 0.474).

CONCLUSION

MRI radiomics-based machine learning may classify deep-seated lipoma and ALT of the extremities with high sensitivity and negative predictive value, thus potentially serving as a non-invasive screening tool to reduce unnecessary referral to tertiary tumor centers.

Fat-Containing Soft Tissue Tumors in Children, Adolescents, and Young Adults: Which Require Biopsy?

PURPOSE

To confirm the overall benignity of fat-containing soft tissue tumors (STT) on a pediatric cohort and to define the clinical and imaging features that warrant a biopsy.

METHODS

A retrospective monocentric study was conducted on patients aged less than 25 years consecutively referred for fat-containing STT to our Comprehensive Cancer Center between 1998 and 2022. Tumor imaging characteristics at diagnosis (US, CT, or MRI) were correlated with pathology.

RESULTS

The database extraction identified 63 fat-containing tumors with clinical, histologic, and imaging data available for review. In total, 58 (92%) were benign tumors: 36 lipoblastomas and lipomas, 12 fibrous hamartomas of infancy (FHI), 5 lipofibromatosis, 2 lipomas arborescens, 2 lipomatosis and 1 spindle-cell lipoma. Five patients (8%) were diagnosed with liposarcoma. Factors significantly correlated with malignancy were age >10 years old (p < 0.001), having a cancer-predisposing condition (p < 0.001), a percentage of fat <25% (p = 0.002), and a presence of myxoid zones (p < 0.001) on imaging.

CONCLUSION

Most fat-containing STT in children may be classified as benign tumors based on clinics and imaging. The indication for biopsy could be limited to patients aged 10 years or more with either a cancer-predisposing condition or imaging features demonstrating either a low-fat component (<25%) or the presence of myxoid zones.

Unusual Presentation of Paraosteal Lipoma in Skull

Paraosteal lipomas are rare benign neoplasm composed of mature adipose tissue with underlying bone changes. They are extremely rare to occur in head and neck region. We present a case of a 40-year-old male with a paraosteal lipoma of occipital region. The diagnosis of the lesion was reached by clinical examination and confirmed on computed tomography (CT) and Magnetic resonance imaging (MRI).

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03494-x.

Review of Soft Tissue Masses of the Foot and Ankle: Magnetic Resonance Imaging Features

A large number of soft tissue masses affect the foot and ankle, with the majority being benign. Benign and malignant soft tissue lesions usually present as lumps, and it is important to differentiate between them to allow for optimal management. Imaging, in particular magnetic resonance imaging (MRI), can contribute to narrow the differential diagnosis of soft tissue masses of the foot and ankle by describing its exact location, internal signal characteristics, presence of enhancement, and its relation to adjacent structures. In this review, we review the literature to describe the most common soft tissue masses around the foot and ankle, focusing on the MRI features of the lesions.

Recurrent intramuscular lipoma at extensor pollicis brevis: A case report

BACKGROUND

This report describes and discusses recurrent intramuscular lipoma (IML) of the extensor pollicis brevis (EPB). An IML usually occurs in a large muscle of the limb or torso. Recurrence of IML is rare. Recurrent IMLs, especially those with unclear boundaries, necessitate complete excision. Several cases of IML in the hand have been reported. However, recurrent IML appearing along the muscle and tendon of EPB on wrist and forearm has not been reported yet.

CASE SUMMARY

In this report, the authors describe clinical and histopathological features of recurrent IML at EPB. A 42-year-old Asian woman presented with a slow-growing lump in her right forearm and wrist area six months ago. The patient had a history of surgery for a lipoma of the right forearm one year ago with a scar of 6 cm on the right forearm. magnetic resonance imaging confirmed that the lipomatous mass, which had attenuation similar to subcutaneous fat, had invaded the muscle layer of EPB. Excision and biopsy were performed under general anesthesia. On histological examination, it was identified as an IML showing mature adipocytes and skeletal muscle fibers. Therefore, surgery was terminated without further resection. No recurrence occurred during a follow-up of five years after surgery.

CONCLUSION

Recurrent IML in the wrist must be examined to differentiate it from sarcoma. Damage to surrounding tissues should be minimized during excision.

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.

Intraosseous lipoma of Calcaneum: A rare incidental finding

Intraosseous lipoma is a rare benign lesion of bone. We present a case of an intraosseous lipoma of the calcaneum detected as an incidental finding, as a well-delineated osteolytic lesion with the central area of calcification, on plain radiography. Diagnosis can be done with a computed tomography scan and/or magnetic resonance imaging.

Intra-articular osteolipoma of the elbow: A case report and a review of the literature

Introduction

Lipomas are the most common benign mesenchymal tumors. The intra-articular localization is exceptional.We report the first case of an intra-articular osteolipoma at the elbow.

Case report

A 36-year-old patient with no pathological history, presented to the emergency room with a two weeks history of a painless, progressively left elbow swelling in a context of apyrexia.Physical examination revealed a hot, edematous left elbow. The gentle mobilization of the joint was painless. Biologie was normal. Initial radiograph showed a well-defined lobular image. Ultrasound revealed an anechoic intra-articular collection associated to a synovium hyperaemia and the MRI shows an aspect of synovitis. An arthrotomy was done via an internal approach of the elbow. Joint fluid was red. A free ossified intraarticular mass was discovered. Bacteriological samples were sterile. Histological examination concluded to an osteolipoma with no histological signs of malignancy. At the last 3-year follow-up, the patient didn't report any pain or functional discomfort. Elbow mobility was complete, with the absence of recurrences.

Discussion

Osteolipoma is defined as a histological variant of lipoma having undergone bone metaplasia. Allen found 06 cases in a series of 635 lipomas over five years. Pain has not been reported in the literature. In our case the pain was explained by the interposition of the tumoral mass between the articular surfaces. Histological examination confirms the diagnosis and recurrences are rare.

Conclusion

Osteolipoma is an extremely rare entity of mesenchymal tumors whose intra-articular location, although exceptional, does not worsen the prognosis.

Head and Neck Lipomas at Uncommon Subsites: A Series of Four Cases

Lipomas are benign soft tissue tumors; the most common ones present in subcutaneous planes distributed throughout the body. However, there are few sites which are unusual location for lipomas. Here, we discuss the presentation of 4 cases of head and neck lipomas at unusual subsites. Though its prevalence is high in the body, lipomas are rarely seen in upper aerodigestive tract and these lesions can cause severe deglutition and respiratory distress problems in addition to cosmetic deformities. In the head and neck, most common location of lipoma is the cheek, followed by the tongue. Tonsillar lipomas are very rare. The mainstay treatment for lipomas is complete surgical excision and recurrence following complete removal is rarely known. We are here discussing a series of 4 cases of lipomas, presenting at uncommon subsites in head and neck region. These include lesions over neck, tongue, palate and tonsillar fossa. Lipomas are benign mesenchymal tumors, that are initially non bothersome. However, with increasing size they can cause severe aerodigestive problems with functional compromise and need complete surgical excision.

Myxolipoma of hand in a child: case report of a rare tumor

Lipomatous tumors account for less than 10% of tumors in the pediatric population. Myxolipomas (a subset of lipoma characterised by mature adipose tissue and abundant mucoid substance) are found to be even rarer. There are a few case reports in different body parts like heart, kidney, oral cavity, epiglottis, cervical and mediastinal regions. However, there are no case reports on the involvement of the hands in any age group. High resolution ultrasound is the imaging modality of choice for the initial evaluation of superficial soft tissue tumors, their site, nature and extent. In conjunction with clinical findings and age of presentation, it helps in narrowing down the differential diagnosis and planning the management. Hyperechoic fatty tumors in the pediatric hand are mostly benign and includes lipomas, lipoblastomas and fibrous hamartomas of infancy as the main differentials. A definitive diagnosis is based on a histo-pathological and molecular cytogenetic examination. This article presents a never before reported case of a rare, large, myxolipoma of the hand in a 22-month-old boy.

Atypical Sites of the Lipoma on the Hand and Fingers: Clinical and Imaging Features and Surgical Outcomes

Background: Lipomas are the most frequent benign soft tissue tumor that are rarely found in the hand and are exceptionally rare on the fingers. The aim of this study was to investigate lipomas of atypical locations, so that they can be taken into account when making a differential diagnosis of a tumor of the hand or fingers. Methods: We studied a group of 27 patients diagnosed with lipoma of the wrist, palm, and fingers. The diagnosis was made by clinical and imaging examinations. Surgical treatment was established based on symptoms of pain, paresthesias, functional impairment, or aesthetic concerns. Treatment outcomes were assessed clinically at 1.5 years post-intervention. Results: Sizes over 5 cm were recorded in five cases, with the largest lipoma being 8 by 5 by 3.5 cm in size and weighing 125 g, located in the palm. There was one case of spontaneous tendon rupture and one case of carpal tunnel syndrome. There was no recurrence recorded at 1.5-year follow-up. Conclusions: Lipomas in the palm and fingers are rare entities (with more men affected), and surgical treatment consists of complete removal of the tumor and providing definitive healing. Despite their rarity, clinicians should consider lipomas when making differential diagnoses of soft tissue tumors of the hand.

Lipofibromatous hamartoma of sciatic nerve: A case report

Introduction

Lipofibromatous hamartoma of the nerve is the fibro-fatty overgrowth within the nerve. Most commonly they occur in the median nerve, ulnar nerves, and a few other nerves but the involvement of the sciatic nerve is very rare. The fibro-fatty infiltration causes palpable neurogenic mass and clinically presents lump, moderate numbness, tingling sensation, and pain in its territory. Magnetic resonance imaging is the gold standard for diagnosis.

Case presentation

We present a case of a 65 years old female, who presented to OPD with a tingling sensation which progressed to pain in the gluteal region and was associated with a tender swelling. MRI showed a giant space-occupying lesion in the sciatic nerve course. The mass was excised and then sent to the histopathological examination which designated the mass as lipofibromatous hamartoma.

Discussion

Unless debilitating, lipomatosis of the nerve doesn't require any intervention as it is a benign condition. Lipofibromatous hamartoma is attributed to the accumulation of fatty and fibrous tissue in the epineurium. Diffusion-weighted imaging in association with conventional magnetic resonance imaging has increased diagnostic yield. The lesion was iso-intense to the subcutaneous fat and there were fine fibrillar appearances inside of it. Simple mass excision was performed on our patient without complications.

Conclusion

Lipofibromatous hamartoma of the nerve are rare soft tissue tumors of nerves and sciatic nerve involvement is even rarer. Correct and careful interpretation of the MRI findings can lead to diagnosis with ease and help prevent unnecessary biopsies.

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Fibrolipomatous hamartoma of the sciatic nerve is a rare disease which may be asymptomatic or may present with palpable tender swelling and tingling sensation in the territory of the nerve.

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High soft tissue resolution MRI is the gold standard for diagnosis and helps prevent unnecessary nerve biopsies.

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Debulking, internal or external neurolysis or radical excision with or without fascicular grafts are various mode of intervention in case of fibrolipomatous hamartoma.

Lipoma and Its Doppelganger: The Atypical Lipomatous Tumor/Well-Differentiated Liposarcoma

Lipomatous tumors are among the most common soft tissue lesions encountered by the general surgeon. Shared history and clinical presentation make differentiation between benign lipomas and low-grade liposarcomas a diagnostic dilemma. This article reviews the epidemiology, clinical history, diagnostic workup, management, natural history, and surveillance of benign lipomas and atypical lipomatous tumors/well-differentiated liposarcomas. Although it is important that aggressive, potentially malignant atypical lipomatous tumors and liposarcomas be managed in a multidisciplinary, preferably high-volume setting, it is equally as important for the nonspecialist general surgeon to be familiar with lipoma and its doppelganger-the well-differentiated liposarcoma.

Lipoma Arborescens of the Upper Extremity With Anatomic Variation of the Palmaris Longus: A Case Report

CASE

We present a case of a patient who suffered from wrist swelling and had symptoms of carpal tunnel syndrome. The patient underwent ultrasound and magnetic resonance imaging, in which signs of joint effusion and a fatty synovial lesion were presented. The treatment included open excision of the tumor. In addition, the palmaris longus muscle had an anatomic variation with proximal and distal tendon portions. The histopathological examination disclosed lipoma arborescens of the synovial membranes of the joints.

CONCLUSION

The recognition of this entity and its characteristics are important not only for correct diagnosis but also for the appropriate treatment.

A Case of Cervical Intraneural Lipoma That Was Removed by Intercapsular Resection with No Resultant Postoperative Neurological Deficit

Intraneural lipomas in peripheral nerves of cervical lesions are extremely rare and have not been previously reported. We present a 48-year-old male with a gradually increasing right cervical mass since 5 years. He visited our department because of pain and difficulty in raising the right upper limb. A tumor about 80 mm in size was palpable in the right neck along the cervical nerve. The tumor was suspected to involve fatty degeneration in schwannoma of cervical nerve origin, for which intercapsular resection was performed under general anesthesia. Histopathologically, bifurcated growth of mature adipocytes with sparse fibrous septa and lack of tumor proliferation of Schwann cells was observed on H&E staining, suggesting a diagnosis of intraneural lipoma. The patient had no new motor or sensory deficits postoperatively and with improvement in his preoperative symptoms.

Mammalian tumor-like organs. 2. Mammalian adipose has many tumor features and obesity is a tumor-like process

BACKGROUND

In previous publications, the author developed the theory of carcino-evo-devo, which predicts that evolutionarily novel organs should recapitulate some features of tumors in their development.

MAIN TEXT

Mammalian adipose is currently recognized as a multi-depot metabolic and endocrine organ consisting of several adipose tissues. Although lipid-storing cells and proteins are ancient, the adipose organ as a whole is evolutionarily novel to mammals. The adipose expansion has remarkable similarities with the growth of solid tumors. These similarities are the following: (1) The capability to unlimited expansion; (2) Reversible plasticity; (3) Induction of angiogenesis; (4) Chronic inflammation; (5) Remodeling and disfunction; (6) Systemic influence on the organism; (7) Hormone production; (8) Production of miRNAs that influence other tissues; (9) Immunosuppression; (10) DNA damage and resistance to apoptosis; (11) Destructive infiltration in other organs and tissues. These similarities include the majority of "hallmarks of cancer". In addition, lipomas are the most frequent soft tissue tumors, and similar drugs may be used for the treatment of obesity and cancer by preventing infiltration. This raises the possibility that obesity, at least in part, may represent an oncological problem. The existing similarities between adipose and tumors suggest the possible evolutionary origin of mammalian adipose from some ancestral benign mesenchymal hereditary tumors. Indeed, using a transgenic inducible zebrafish tumor model, we described many genes, which originated in fish and were expressed in fish tumors. Their human orthologs LEP, NOTCH1, SPRY1, PPARG, ID2, and CIDEA acquired functions connected with the adipose organ. They are also involved in tumor development in humans.

CONCLUSION

If the hypothesis of the evolutionary origin of the adipose organ from the ancestral hereditary tumor is correct, it may open new opportunities to resolve the oncological problem and the problem of the obesity epidemic. New interventions targeting LEP, NOTCH1, SPRY1, PPARG, ID2, and CIDEA gene network, in addition to what already is going on, can be designed for treatment and prevention of both obesity and tumors.