Parosteal Lipoma.

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

Parosteal Lipoma Overlying an Osteochondroma of the Hyoid Bone: A Case Report and Literature Review.

Parosteal lipomas and osteochondromas of the head and neck are uncommon benign tumors, constituting a small fraction of lipoma and bone tumor cases. We present a unique case of a 66-year-old male with a parosteal lipoma overlying an osteochondroma in the anterior midline neck, causing dysphagia. Surgical excision confirmed the diagnosis, and a literature review revealed similar cases predominantly adjacent to the mandible or calvaria. This case emphasizes the need to have parosteal lipoma and osteochondroma on the differential diagnosis for patients presenting with a firm mass of the central neck, especially with a history of trauma. Laryngoscope, 2023.

Unraveling the Mystery of Parosteal Lipoma of the Distal Femur: A Rare Case Report.

Introduction: Among all the primary bone tumors and all the type of lipomas, parosteal lipomas stand for <0.1% and 0.3%, respectively, which mostly consists of fully developed adipose tissue with or without a bony component. Patients with this tumor usually have bony lesions (59.2%), necessitating a differential diagnosis of malignant tumors. Case Report: Here, we analyze a case report of a 9-year-old boy, who developed a parosteal lipoma in the distal femur. A massive, well-defined, lobulated, mostly fat-intensity lesion of 10 cm by 6 cm by 8 cm was seen on an magnetic resonance imaging scan of the right distal femur. After the lump was removed, the pathologically reveals a parosteal lipoma without any malignant changes. Conclusion: Finally, it should be noted that parosteal lipomas are less common neoplasias with no known malignant potential. Since these tumors can be removed with mild impact to nearby structures, the lower limb's functionality is kept intact.

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.

Case report: Recurrent parosteal lipoma at Dr. Moewardi hospital.

Background: Parosteal lipoma is a rare and benign neoplasm originating from mature adipose tissue near the periosteum. Clinically, it is difficult to diagnose due to its similarity to the clinical manifestation of sarcoma, so imaging, histopathology, and immunohistochemistry examinations are necessary. Case presentation: A 54-year-old woman presented with lump on the right thigh that had gone through surgery eight years prior, with a diameter of 20 cm, with a partly hard and partly soft consistency, the patient was diagnosed with suspected recurrent liposarcoma. We performed wide excision and histopathological results showed a proliferation of bone cells and cartilage cells that were lobulated, surrounded by a proliferation of fat cells with no pleomorphism or immature cells. Discussion: Parosteal lipomas are neoplasms derived from adult adipose tissue, usually connected to the periosteum, and rare and benign. Two theories of pathogenesis of parosteal lipomas. (1) tumors arise from the differentiation of stem cells derived from adipose tissue, (2) the tumor is derived from secondary metaplasia of fibroblasts due to recurrent trauma, metabolic changes, or ischemia. Based on the theory, it is likely that in this case is due to the presence of differentiation of adiposa tissue due to the non-acquisition of a history of trauma. Conclusion: Parosteal lipoma is a rare case of benign neoplasm, which is difficult to diagnose clinically due to its similar sarcoma, thus requiring imaging and histopathological examination. The treatment of choice is wide excision by taking the entire tumor to prevent a recurrence.

Parosteal lipoma of the rib: A rare condition in an uncommon location.

A 36-year-old female patient was diagnosed with a parosteal lipoma arising from the left 3rd rib. This was preluded by a 5-year history of an asymptomatic and stable mass at the medial aspect of the left scapula. It had displayed an interval enlargement in the preceding 3 months which prompted investigation to rule out an aggressive lesion. The patient was investigated with CT, MRI and PET scan which demonstrated a well-circumscribed juxtacortical fatty mass with osseous excrescence and no enhancing soft tissue components or FDG avidity in the fatty component, in keeping with a parosteal lipoma. CT-guided biopsy allowed histopathological correlation which facilitated the exclusion of an aggressive lesion and supported the imaging diagnosis. This case is a pertinent educational tool for radiologists and orthopaedic surgeons as it characterises a rare and benign pathology in an uncommon location, with mimicry of malignant differential diagnoses such as liposarcoma and chondrosarcoma. We aim to bring awareness to this condition and its typical imaging characteristics and thus allowing radiologists to make more confident conclusions in future cases.

A Case Report on Parosteal Lipoma Stretching the Posterior Interosseous Nerve Without Causing Palsy.

Lipomas are benign soft tissue tumors that can be either superficial or deep. Superficial lipomas are mostly asymptomatic whereas deep-seated lipomas can occasionally cause symptoms if they grow adjacent to neurovascular structures. In this report, we present a case of parosteal lipoma of the right proximal forearm in a 47-year-old male, which was initially diagnosed as intramuscular lipoma stretching posterior interosseous nerve (PIN), with no neurological complaints during both preoperative and postoperative periods.

Parosteal Lipoma of the Proximal Phalanx of Hand.

Parosteal lipomas are rare benign tumors accounting for less than 0.1% of all primary bone tumors. Only 3 cases of parosteal lipoma have been previously described affecting the distal and middle phalanges. We describe a case of parosteal lipoma in a 45-year-old man involving the proximal phalanx of the right middle finger. The tumor was marginally excised with the osseous attachment. There was no clinical or radiological recurrence at a follow-up of 2 years, with full range of movement at the proximal interphalangeal joint.

Posterior interosseous nerve entrapment due to bilobed parosteal lipoma.

Entrapment of posterior interosseous nerve (PIN) can be due to fracture dislocation of elbow, fibrous arcade of Frohse, neoplasms (lipoma, schwannoma), ganglion cysts and rheumatoid synovitis. Parosteal lipomas are extremely rare. These tumors grow slowly and as they grow, they can compress a nearby nerve producing sensory and motor disturbances. Till date less than 50 cases of PIN entrapment due to parosteal lipoma have been reported in literature. However, to the best of our knowledge, none was bilobed. A 54-year-old female patient presented with progressive weakness of the right-hand extensors including thumb for the last 5 months with no sensory loss. Clinico-radiological findings and electophysiological studies revealed parosteal lipoma causing entrapment of PIN. Surgical excision of the lesion was done through posterior approach. The excised mass was sent for histopathological examination which confirmed the diagnosis of lipoma. Appreciable recovery was first noticed at 3 months and complete recovery was seen at 7 months. No recurrence was seen until 2 years of follow up. Urgent surgical excision is necessary to prevent entrapment of this nerve and facilitate early functional and neurological recovery.

Parosteal Lipoma of Proximal Radius: A Case Report of an Unusual Swelling and Review of Literature.

INTRODUCTION: Lipomas are considered to be benign tumors comprising 50% of all soft tissue tumors. They originate from mesodermal germ layer but are classified based on component tissue and location. Parosteal lipomas are frequently located at the extremities, particularly at diaphysis or diametaphysis of long bones. CASE REPORT: Here, we report a case of parosteal lipoma with a delayed presentation involving dominant right forearm without any neurological deficits to create awareness of the rare existence of this benign tumor. CONCLUSION: A prompt diagnosis of such tumors has to be done as early as possible.

Thoracoscopic resection of parosteal lipoma of the rib using orthopedic electric micro drill.

Parosteal lipoma derived from the rib is extremely rare and is usually resected through open thoracotomy despite its benign nature. A 33-year-old man who had no symptoms was referred to our hospital for treatment of a 30-mm chest wall mass that has slightly increased in size during 2 years of follow-up. En bloc resection of the tumor with parts of the 3rd and 4th ribs was performed through a complete thoracoscopic approach using orthopedic electric micro drill. This was the first report on a case of parosteal lipoma of the rib that was resected by a complete thoracoscopic procedure.

Parosteal Lipoma Associated with Underlying Recurrent Bizarre Parosteal Osteochondromatous Proliferation (Nora's Lesion) of the Hand / 대한정형외과학회잡지

Parosteal lipoma is a benign tumor of the mature adipose tissue that contacts the periosteum of the underlying bone directly. The tumor commonly arises in the long bones, such as the femur, radius or tibia, and often exhibits underlying osseous changes, such as a cortical hyperostosis or erosion. Parosteal lipoma arising in a finger is rare. Furthermore, there are no reports of parosteal lipoma associated with underlying bizarre parosteal osteochondromatous proliferation. The authors present a rare case of parosteal lipoma of the proximal phalanx of the little finger accompanied by recurrent bizarre paroteal osteochondromatous proliferation in a 64-year-old male patient who had previously undergone an excisional biopsy at the same location 8 years earlier.

Parosteal lipoma as a rare cause of peripheral neuropathy and local irritation: A report of 12 cases.

OBJECTIVE: The aim of this study was to evaluate the clinical features and functional results of patients with parosteal lipomas. METHODS: A total of 12 patients (8 females and 4 males; mean age: 45 (10-62) years) with parosteal lipomas who were treated between April 1986 and April 2014, were included into the study. The medical records of the patients were reviewed to analyze the clinical features and functional results of the patients. RESULTS: Of the 12 lipomas, 5 were localized in the proximal arm, 4 in the forearm, 1 in the distal arm, 1 in the distal thigh and 1 in the distal tibia. All patients presented with a progressive, slow-growing mass that was associated with thumb extension weakness in 1 case, and brachialgia-like symptoms in 1 case. Plain radiographs showed a juxtacortical mass in all cases and irregular ossification in 3 cases. In all cases, marginal excision was performed and no clinical recurrence was observed after a mean follow-up of 16 months. CONCLUSION: Parosteal lipomas are uncommon tumors that can be diagnosed with their characteristic radiological features. Parosteal lipomas occurring in the proximal radius may easily cause paralysis of the posterior interosseous nerve or muscle weakness. LEVEL OF EVIDENCE: Level IV, Therapeutic study.

Posterior Interosseous Nerve Syndrome Resulting from Parosteal Lipoma of the Proximal Radius: An Elusive Diagnosis Yet Excellent Outcome.

A 53-year old man presented with seven months history of progressive weakness of extension of the digits and the thumb of the left hand. The wrist extension was normal and sensations were also intact. The patient had also been noticing a progressively enlarging lump on the lower anterolateral aspect of the left antecubital fossa for the last three months. Physical examination andelectro diagnostic studies revealed motor deficit along the posterior interosseous nerve (PIN) distribution with preservation of sensations. Also a soft tissue solitary lump (measuring 6×5 cm in its greatest dimensions) was palpable in the left antecubital fossa. The magnetic resonance imaging (MRI) of the forearm revealed a well-defined, non-enhancing, homogenous, fat intensity lesion in the left antecubital fossa, attached to the proximal radius. The patient underwent surgical excision of the lump with decompression of the PIN in the radial tunnel. Histopathology confirmed the diagnosis of parosteal lipoma. Although the diagnosis was elusive at the very outset, yet prudent clinical judgment, appropriate ancillary investigations and timely surgical intervention resulted in optimal functional recovery of the hand drop. There was complete motor recovery at 4-months follow up with no recurrence of the lipomaafter one year.

Parosteal Lipoma in the Metatarsus: A Case Report / 대한족부족관절학회지

We experienced a rare case of parosteal lipoma, which located on the periosteum of the foot 4th metatarsus. A 22-year-old woman visited the hospital with painful mass in her foot. Based on the assessment of plain radiographs, computed tomography scan, and magnetic resonance image, it was suspected as lipoma. Marginal excision was performed and parosteal lipoma was confirmed histologically. Any local recurrence and complications were not observed in 2 years after surgery.

Parosteal lipoma of humerus-A rare case.

INTRODUCTION: Parosteal lipoma is an extremely rare benign tumor composed mainly of mature adipose tissue with a bony component. PRESENTATION OF CASE: This study reports the case of a 65-year old woman with a big mass on the posteromedial aspect of the right upper arm since 1 year. The swelling was a slow growing, painless, nontender, immobile mass which was not fixed to skin. She had no complaints of painful or restricted movements of the shoulder joint. She had no history of trauma to the upper limb. MRI revealed a large 13cm×5cm×8cm well defined, nonenhancing, lobulated, heterointense, predominantly fat intensity lesion with a small area of chondroid component measuring 2cm×1.6cm in posteromedial aspect of proximal right humerus, seen completely separate from the adjacent muscles. DISCUSSION: The patient underwent surgery under general anesthesia. Vertical elliptical incision was taken over the posterior border of the upper arm over the mass. The tumor was below the lower part of deltoid near the upper end of humerus, which formed the roof, and between the long and medial heads of triceps muscles. A part of tumor, measuring 6cm×5cm×5cm, was under the long head of triceps displacing it along with radial nerve and vessels medially while the other part, measuring 7cm×6cm×3cm, was under the medial head of triceps displacing it laterally. The tumor was excised undocking its periosteal attachment. The specimen weighed 250g. On histopathology, the lesion was composed of mature lipocytes that had an intimate relationship with the periosteum. No cellular atypia or lipoblasts were seen. CONCLUSION: Parosteal lipomas are rare neoplasias with no proven malignant potential. These tumors can be resected without much damage to the adjacent structures, thus preserving the function of the upper limb.

Parosteal Lipoma of the Femur with Hyperostosis: A Case Report / 대한골관절종양학회지

Parosteal lipoma is a rare kind of lipoma that occurring adipous tissue around the periosteum. It has been reported most commonly in the femur, the radius, the tibia and the fibular. Treatment consists of resecting the lipomatous tumor with further exeresis of the bone and periosteal excrescence in cases with hyperostosis. The authors report a rare case of parosteal lipoma occurring at the medial portion of the femur shaft with a review of the relevant literatures.

CT findings of parosteal lipoma with hyperostosis / 中华放射学杂志

Objective To determine the characteristics of paresteal lipomas with hypemstosis (esteochondromas or osseous protuberances)on CT images and to improve the knowledge of diagnosis and differential diagnosis of the disease.Methods CT images and clinical history of 6 patients with pathologically confirmed parosteal lipemas with hyperostosis were retrospectively reviewed.All of the 6 patients underwent plain CT scans.Results CT images clearly show lipomas and osseous projections or osteochondroma in the 6 cases.Parosteal lipomas were found with osteochondronms in 2 cages(1 at the isehium.and the other 1 at the femoral trochanter)and willl osseous protuberances in 4 cases(2 at the diaphysis offemurs.1 at the diaphysis oftibia and the other 1 at the sternum).These osteochondromas and ossous protuberances were surrounded by the adipose component of the neoplasm and had a firm attachment oftlle neoplasm to the underlying bone.The size ofthe osseous projections varied from 0.3 cm x1.2 cm to 6.0 cm x 4.0 cm.The shape of the osgeous projections was various.Osteochondromas found in 2 cases showed cortical continuity with the adjacent bone together with marrow continuity with tlle adjacent bone marrow.In the 4 cages of parosteal lipama with osseous protuberances,2 to 4 osseous protuberances were found in 2 case8 and solitary osseous protuberance were found in the other 2 cases.The lipomatoas companent showed typical features of adipose tissue on all images.The size of the lipomas varied from 3.0 cm ×2.0 cm to 11.0 cm×10.0 cm with clear border.Fibrous septa of different thickness were found within the adipose tissue.There was essification and (or) calcification in 1 case and muscle atrophy in 2 espies.Conclusions CT scan is useful in the presurgical evaluation of parosteal lipomas witll osteochondromas or osseous protuberances became it can demonstrates the morphology,location and extent of the lesions.and it can show their relationship to the surrounding structures. It is important for differential diagnosis and preoperative assessment of the lesion.

Manifestation of clinical image and pathalogical characters of parosteal lipoma(literature review with a report of 14 cases) / 中国矫形外科杂志

[Objective]The naming,pathogeny,clinic,patho logical character and image manifestation of the parosteal lipoma were discussed in this paper combined with the literatures.[Method]Combined the 20 cases reported in the internal literatures,the photographs have been taken in all the 34 cases,CT in the 18 cases,MRI in the 4 cases.[Result]The data demonstrated that this disease betided in any age,more in the adult,developed more in the long canal bone of the limb,and developed in the flat bone(pelvis,scapula,costal bone,patella),anomaly bone(thoracic verthbrae,lumbar,ansa sacralis),cauda bone,short canal bone and instep bone secondly.The rate of the error diagnosis were 40.91% in the clinic,27.27% in the X-ray and no one in the CT and MRI.The excision was done in all the 34 cases,and lipoma were diagnosed in pathology,3 cases were malignant slightly.Followed up for 2 to 10 years,only 1 cases recurring and malignant.[Conclusion]The name of the parosteal lipoma is optimal,the pathogeny is not clear,and related to the heredity,hurt and inflamation.There is lipoma with bone pedicel in pathology;and adipose tissuse in cytology.There are characteristic changes in the X-ray,CT and MRI.

Posterior interosseous nerve compression secondary to a parosteal lipoma: Case report and literature review.

An unusual case of limited radial nerve palsy secondary to a parosteal lipoma is presented, along with a thorough review of the literature. Palsy of the posterior interosseous nerve secondary to compression by a lipoma is a rare occurrence. Most cases tend to occur in the fifth to eighth decades of life. The pattern of physical symptoms may be quite variable. A high degree of suspicion must be maintained in the setting of unexplained symptoms. The literature review revealed the presence of a diagnostic proximal forearm radiolucent mass in 13 of 15 patients. Although they are used as diagnostic aids, computed tomography and magnetic resonance imaging have not been shown to alter management. Though benign tumours constitute a minority of such cases, a plain radiograph is recommended in addition to electromyographic and nerve conduction studies.

Voici la description d'un cas plutôt rare de paralysie partielle du nerf radial, secondaire à un lipome parostéal, suivie d'un examen exhaustif de la documentation. La compression du nerf interosseux postérieur par un lipome donne rarement lieu à la paralysie. La plupart des cas se rencontrent chez les personnes âgées entre 50 et 80 ans. Les symptômes physiques peuvent varier considérablement. Il faut entretenir des doutes importants devant des symptômes inexpliqués. L'examen de la documentation a révélé la présence diagnostique d'une masse radiotransparente dans l'avant-bras proximal chez 13 patients sur 15. Bien qu'elles servent d'outils d'aide au diagnostic, la tomodensitométrie et l'imagerie par résonance magnétique ne modifient pas pour autant la prise en charge. Même si les tumeurs bénignes sont rares en pareils cas, il est recommandé de procéder à une radiographie simple, outre l'électromyographie et l'exploration de la conduction nerveuse.