Type Of Lipoma Research Articles

Lump on back: a rare case of parosteal lipoma of scapula.

Lipomas are benign tumors of mature adipose tissue which can occur in subcutaneous, intramuscular, intermuscular, parosteal, and intraosseous compartments. Parosteal lipoma is a rare type of lipoma, accounting for less than 0.1% of primary bone neoplasms and 0.3% of all lipomas. Parosteal lipomas commonly arise in the femur and extremities. Around 150 cases have been reported in English literature with scapula being a rare site of involvement. They are known to be associated with underlying bony changes like focal cortical hyperostosis, pressure erosion of the underlying bone, and bowing deformity or with underlying osteochondroma. We report a rare case of a parosteal lipoma arising in the scapula with a bony excrescence in a 38-year-old male.

Surgical treatment of complex spinal cord lipomas

This paper shows the long-term benefits of total/near-total resection of complex spinal cord lipomas and meticulous reconstruction of the neural placode, and specifically, its advantage over partial resection, and over non-surgical treatment for the subset of children with asymptomatic virgin lipomas. The technique of total resection and placode reconstruction, together with technical nuances, are described in detail. We added 77 patients with complex lipomas to our original lipoma series published in 2009 and 2010, to a total of 315 patients who had had total or near-total resection and followed for a span of 20 years. Long-term outcome is measured by overall progression-free survival (PFS) with the Kaplan-Meier analysis, and by subgroup Cox proportional recurrence hazard analysis for the influence on outcome of 4 predictor variables of lipoma type, presence of symptoms, prior surgery, and post-operative cord-sac ratio. These results are compared to an age-matched, lesion-matched series of 116 patients who underwent partial lipoma resection over 11 years. The results for total resection is also compared to two large published series of asymptomatic lipomas followed without surgery over 9 to 10 years, to determine whether prophylactic total resection confers better long-term protection over conservative treatment for children with asymptomatic lipomas.. The PFS after total resection for all lipoma types and clinical subgroups is 88.1 % over 20 years versus 34.6 % for partial resection at 10.5 years (p < 0.0001). Culling only the asymptomatic patients with virgin (previously unoperated) lipomas, the PFS for prophylactic total resection for this subgroup rose to 98.8 % over 20 years, versus 67 % at 9 years for one group of non-surgical treatment and 60 % at 10 years for another group of conservative treatment. Our own as well as other published results of partial resection also compare poorly to non-surgical treatment for the subset of asymptomatic virgin lipomas. Multivariate subgroup analyses show that cord-sac ratio is the only independent variable that predicts outcome, with a 96.9 % PFS for ratio < 30 % (loosest sac), 86.2 % for ratio between 30 and 50 %, and 78.3 % for ratio > 50 % (tightest sac), and a threefold increase in recurrence hazard for high ratios (p = 0.0009). Pre-operative patient profiling using multiple correspondence analysis shows the ideal patient for total resection is a child less than 2 years old with a virgin asymptomatic lipoma, who, with a PFS of 99.2 %, is virtually cured by total resection. Total/near-total resection of complex lipomas and complete reconstruction of the neural placode achieves far better long-term protection against symptomatic recurrence than partial resection for all lesions; and for the subset of asymptomatic virgin lipomas, also better than non-surgical treatment. Partial resection in many cases produces worse outcome than conservative treatment for asymptomatic lesions.

Histological and molecular features of lipomatous and nonlipomatous adipose tissue in familial partial lipodystrophy caused by LMNA mutations

Type 2 familial partial lipodystrophy (FPLD2) is a rare adipose tissue (AT) disease caused by mutations in LMNA, in which lipomas appear occasionally. In this study, we aimed to histologically characterize FPLD2-associated lipomatosis and study the expression of genes and proteins involved in cell cycle control, mitochondrial function, inflammation and adipogenesis. One lipoma and perilipoma fat from each of four subjects with FPLD2 and 10 control subjects were analysed by optical microscopy. The presence of inflammatory cells was evaluated by immunohistochemistry. Real-time RT-PCR and Western blot were used to evaluate gene and protein levels. Adipocytes from lipodystrophic patients were significantly larger than those of controls, in both the lipomas and perilipoma fat. Lipodystrophic AT exhibited CD68(+) macrophages and CD3(+) lymphocytes infiltration. TP53 expression was reduced in all types of lipomas. At protein level, C/EBPβ, p53 and pRb were severely disturbed in both lipodystrophic lipomas and perilipoma fat coming from lipoatrophic areas, whereas the expression of CEBPα was normal. Mitochondrial function genes were less expressed in lipoatrophic fat. In both lipomas and perilipoma fat from lipoatrophic areas, the expression of adipogenes was lower than controls. Even in lipomas, the adipogenic machinery is impaired in lipodystrophic fat coming from lipoatrophic regions in FPLD2, although the histological phenotype is near-normal, exhibiting low-grade inflammatory features. Our results suggest that the p53 pathway and some adipogenic proteins, such as CEBPα, could contribute to the maintenance of this near normal phenotype in the remnant AT present in these patients.

Adipose and Myxoid Tumors of Childhood and Adolescence

Adipose and myxoid tumors in children are an unusual and challenging group of neoplasms that have some unique aspects in contrast to these tumors in adults. Less than 10% of soft tissue neoplasms in the 1st 2 decades of life have an adipose phenotype and most are benign. The most common are various types of lipoma and lipoblastoma. Liposarcoma in young patients is rare and has a distinctive distribution of histologic subtypes, including classic myxoid liposarcoma, and unusual variants, such as pleomorphic-myxoid liposarcoma. Pathologic examination enhanced by adjunct techniques, such as immunohistochemistry and cytogenetic or molecular genetic studies, is useful for classification of difficult cases. Myxoid tumors can overlap with adipose tumors and are included in this review because of the morphologic similarities and importance of diagnostic accuracy. This article reviews the clinicopathologic features of adipose and myxoid tumors with an emphasis on the unique aspects of these neoplasms in children and adolescents and the differential diagnosis.

Oral spindle cell lipomas

Spindle cell lipoma is an histological type of lipoma which are rarely found in the oral cavity. We describe two cases of intraoral spindle cell lipomas. The pa- tients were men and presented painless slow growing masses in the left cheek and hard palate, measuring 50 × 30 mm and 23 × 20 mm respectively. Microsco- pically, both lesions presented a solid proliferation of mature fat cells intermixed with bundles of connec- tive tissue. Cells were immunopositive for S100 pro- tein and CD34 (one case), with low mitotic activity (Ki-67). The final diagnosis was spindle cell lipomas. The lesions were excised and no recurrence was no- ticed after six months. Oral spindle cell lipomas are unexpected to occur in the oral mucosa, and the main differential diagnosis is well-differentiated liposar- coma/atypical lipoma. Lesions are treated with sur-gical excision and recurrences are rare.

Long-Term Outcome of Total and Near-Total Resection of Spinal Cord Lipomas and Radical Reconstruction of the Neural Placode, Part II

To show the long-term benefits of total and near-total resection of complex spinal cord lipomas and reconstruction of the neural placode. We analyzed 238 patients with dorsal, transitional, and chaotic lipomas who had total resection as described in part I for overall progression-free survival probability (PFS, Kaplan-Meier analysis) over 16 years. We also analyzed subgroup proportional recurrence hazard (Cox analysis) of 6 outcome predictors of sex, lipoma type, age, preoperative symptoms, previous surgery, and postoperative cord-sac ratio. These results were compared with an age-matched, lesion-matched series of 116 patients followed for 11 years after partial lipoma resection and with the Parisian series of nonsurgical treatment. The immediate effects of surgery were similar between total and partial resection: both achieved greater than 95% symptom stabilization or improvement rate. The neuro-urologic complication rates for the groups were also similar, 4.2% and 5.2% for total and partial resection, respectively. The combined cerebrospinal fluid leakage and wound complication rate of total resection was much lower at 2.5% than the 6.9% for partial resection, but both were better than published rates. The overall PFS for total resection was 82.8% at 16 years, comparing much more favorably with 34.6% for partial resection at 10.5 years (P < .0001). Culling only the asymptomatic patients with virgin (previously unoperated) lipomas to match the patient profile of the Parisian series, the PFS for prophylactic total resection for this subgroup increased to 98.4% at 16 years, versus 67% at 9 years for no surgery and 43.3% at 10.5 years for our own partial resection series, with a remarkable statistical difference between total and partial resection (P = .00001). Subgroup analyses showed that sex and lipoma type did not affect outcome. For the other predictor variables, while univariate analyses showed that young age, absence of symptom, and virgin lipomas correlated with better statistical PFS than older age, symptoms, and redo lipomas, these effects vanished with multivariate analyses. Cord-sac ratio stood alone as the only influential outcome predictor in multivariate analysis, with a 96.6% PFS for a low ratio of <30% and an 80.6% progression-free probability for a high ratio of >50%, and a 3-fold increase in recurrence hazard for high ratios (P = .0009). This suggested that all the individual effects of the other predictor variables could be reduced to whether a low cord-sac ratio could be achieved with total lipoma resection and placode reconstruction. Cord-sac ratio was the obvious factor that differentiated the outcomes between total and partial resection, the latter associated with a >90% chance of having a high cord-sac ratio. Total and near-total resection of lipomas and complete reconstruction of the neural placode produced a much better long-term progression-free probability than partial resection and nonsurgical treatment. The perioperative complications for total resection were low and compared favorably with published results. A low postoperative cord-sac ratio and well-executed placode neurulation were strongly correlated with good outcome. The ideal preoperative patient profile with early disease stabilization and the best recurrence-free probability is an asymptomatic child less than 2 years without previous lipoma surgery. There are strong indications that partial resection in many cases produces worse scarring on the neural placode and worse prognosis than no surgery.

Osteolipoma of the buccal mucosa

Lipomas are benign mesenchymal neoplasms of soft tissue that can be found in any part of the human body. Conversely, their presence in the oral mucosa is rather uncommon, with approximately 4% of the cases occurring in the oral cavity. In such cases, they are likely to have originated from mature adipose tissue and to be among several described histological variants of lipomas, which are identified according to the predominant type of tissue. There is a rare lipoma, known as an osteolipoma or an ossifying lipoma; however, little has been written this type of lipoma characterized by a classical lipoma with areas of osseous metaplasia. Considering the few cases of oral osteolipomas previously described in the English-related literature and the consequent risk of misdiagnosis and overtreatment, this paper describes an extreme case of an osteolipoma affecting the buccal mucosa of an adult patient. This paper focuses particularly on the pathogenesis of this lesion and the discussion of a correct diagnosis.

Retroperitoneal Lipoma Arising from the Urinary Bladder

Retroperitoneal benign lipomas are extremely rare and represent about 2.9% of all primary retroperitoneal tumors. About 80% of the tumors in the retroperitoneal cavities are malignant neoplasms. We experienced a case of a retroperitoneal lipoma simulating an ovarian mature cystic teratoma. A diagnosis was correctly made by magnetic resonance imaging (MRI) prior to surgery, and a total tumorectomy was performed. The retroperitoneal lipoma was recognized to have arisen from the urinary bladder. Histological sections revealed a tumor consisting of typical adipose cells without atypia. These types of lipomas should be carefully followed-up because they often recur and undergo malignant transformations.

Embryopathogenetic surgicoanatomical classification of dysraphism and surgical outcome of spinal lipoma: a nationwide multicenter cooperative study in Japan

The natural history of asymptomatic spinal lipoma in infancy remains unclear, and the indication for the prophylactic untethering operation is still debatable. To address this question, a multicenter cooperative study for the treatment of spinal lipoma was performed by the 7 most active institutions in neurosurgical care for spina bifida in Japan between 2001 and 2005. Patients were classified using the embryopathogenetic surgicoanatomical classification. Their neurosurgical postoperative course was analyzed using the Spina Bifida Neurological Scale. Among 261 patients, 159 were asymptomatic and 102 were symptomatic. Of the 136 patients for whom prophylactic surgeries were performed, 135 remained asymptomatic and only 1 (0.4%) of the 261 patients presented with mild sensory disturbance. Mild foot deformity was identified in 1 (4.3%) of 23 conservatively observed patients. Of 100 symptomatic patients, deterioration after surgery was seen in 6%, and improvement in 44%. Complete resolution of symptoms was seen in only 14.2%. Filar types for patients > 3 years old improved in Spina Bifida Neurological Scale scores from 12.3 to 14.0. The mean age of symptomatic patients with lipomyelomeningocele was the youngest of all (1.3 years), which indicates lipomyelomeningocele may deteriorate in early infancy. Improvements from surgery were seen for all types of lipoma except the caudal type, presenting at an older mean age (15 years). A low rate of postsurgical worsening indicates that surgeries for asymptomatic and symptomatic lipomas are safe. Surgeries done after the onset of symptoms seldom cure the patients. These two results support early untethering for any kind of lipoma; however, further study of the natural history is required.

口腔に発生した脂肪肉腫の２例

Liposarcoma is a malignant tumor of the soft tissues, but it is extremely rare in the oral cavity, particularly in the tongue. The tumor typically presents as a painless, slowly enlarging mass, and wide surgical excision is important for successful management. We describe 2 patients with liposarcoma involving the tongue and buccal region, with reference to the existing literature.Patient 1 was a 60-year-old woman with a mass arising in the right inferior surface of the tongue. The suspected clinical diagnosis was lipoma of the tongue. Patient 2 was a 42-year-old man with swelling of the right cheek. The suspected clinical diagnosis was pleomorphic adenoma of the buccal region. Tumor excision followed by rapid intraoperative pathological examination in both patients revealed no apparent malignancy. However, the postoperative histopathological diagnosis was well-differentiated liposarcoma in patient 1 and well-differentiated type liposarcoma with metaplastic bone formation in patient 2. We thus surgically excised the tumor with a wide safety margin in patient 1 and applied postoperative radiotherapy to the buccal cheek in patient 2. Both patients remain free of reccurence and metastasis.These findings show that low-grade well-differentiated liposarcoma can be difficult to distinguish from other types of lipoma.

Surgery for spinal cord lipomas

To analyze the results after surgery for spinal cord lipomas. The authors report their results of management of 63 non consecutive random children with spinal cord lipomas treated over a period from 2001 to 2005, at the All India Institute of Medical Sciences, New Delhi, India, a tertiary care neurosurgical centre. There were 63 cases consisting of 32 (52%) conus lipomas, 14 (22%) filum lipomas, 14 (22%) lipomeningomyelocele (lipoMMC), 2 (2.5%) cases of lipomyelocystocele and one (1.5%) case of mixed lipoma. None of the patients who were asymptomatic before surgery deteriorated neurologically, irrespective of the type of lipoma till the last follow up. In those patients with preexisting neurological deficits, the improvement in motor, sensory and bladder abnormalities was only to an extent of 15 %, 16 % and 21 % respectively. None of the children with preexisting neurological deficit regained overall normal function. Nevertheless, the improvement in symptoms after surgery made the patients lead a better social life. Only 6 % of patients developed deterioration in neurological function after surgery, all of them occurring in patients already having pre-operative deficits. The authors recommend prophylactic surgery which is safe and effective in preventing neurological deficits, irrespective of the type of lipoma. Most of the patients benefit only to some extent even after surgery, once they develop neurological dysfunction. A close long term follow up is recommended in order to detect neurological deterioration even in children operated prophylactically.

Factors in neurological deterioration and role of surgical treatment in lumbosacral spinal lipoma.

The purpose of this study was to determine factors that might be involved in neurological deterioration and the role of surgical treatment in patients with lumbosacral spinal lipoma. Pre- and postoperative courses of 34 patients were retrospectively analyzed. The age at surgery ranged from 1 month to 47 years. The records of preoperative neurological status indicated that older patients had more severe deficits, while all 8 asymptomatic patients were under 5 years of age. Motor deficits were noted in 9 patients, in 7 of whom the lipoma extended cranially beyond the L5 level. Transitional-type lipomas were accompanied by more severe deficits (asymptomatic 1, symptomatic 17) than other types (asymptomatic 7, symptomatic 9). Postoperative follow-up periods ranged from 5 months to 13 years. During these periods, 7 of the 8 asymptomatic patients remained neurologically intact. Nine of the 26 symptomatic patients improved. Age, extension of the lipoma in the spinal canal and type of lipoma will influence the preoperative neurological status of the patients. Early untethering surgery is recommended in patients with large lipomas extending beyond the L5 level.

Fibrohistiocytic differentiation in subcutaneous fatty tumors. Study of spindle cell, pleomorphic, myxoid, and atypical lipoma and dedifferentiated liposarcoma cases composed in part of CD34+ fibroblasts and FXIIIa+ histiocytes.

Subsets of dendritic cells, fibroblasts which express the human progenitor cell antigen CD34 or histiocytes which express coagulation factor XIIIa (FXIIIa), are present in fat and in collagenous connective tissue. As components of the microvascular unit, these fibrohistiocytic cell subsets may interact during stromal remodeling, repair, and neoplasia. We studied white fat and subcutaneous fatty tumors to determine if CD34 and/or FXIIIa+ "fibrohistiocytic" dendritic cell subsets are involved in their morphogenesis. Three lipomas (L), 1 intramuscular lipoma (IL), 1 myxoid lipoma (ML), 2 pleomorphic lipomas (PL), 2 spindle cell lipomas (SCL), 8 angiolipomas (AN) in 4 patients, 1 atypical lipoma/well-differentiated liposarcoma (AL), 1 de novo dedifferentiated liposarcoma (DL), and 1 recurring atypical myxoid signet ring lipomatous tumor were examined for CD34, FXIIIa and in some cases for CD31, desmin, Ki 67, or S-100. Normal fat has scattered CD34+ dendritic cells and small FXIIIa+ dendritic histiocytes among variably S-100+ adipocytes. The CD34 and FXIIIa+ dendritic cells are more numerous near vessels and within fibrovascular septae. In L and IL, CD34 and FXIIIa+ dendritic cells are activated and some adipocytes express CD34. Mesenchymal areas of SCL, PL, ML, and AL and DL are composed of CD34+ dendritic cells with CD34+ but FXIIIa-negative floret cells in PL or atypical cells in AL and DL. FXIIIa+ dendritic cells are numerous in these lesions, comprising 30-40% of cells in SCL and PL, and 50% in ML, AL, and DL. AN have focal CD34+ interstitial cells and plump FXIIIa+ cells that in one case resembled multivacuolated lipoblasts. The myxoid signet ring lipomatous tumor was CD34 negative with few FXIIIa+ cells. We conclude that subsets of CD34+ and FXIIIa+ dendritic microvascular cells are present in normal fat and proliferate together in various types of lipomas and in at least some dedifferentiated liposarcomas.

Intramuscular (Subfascial) Vascular Spindle Cell Lipoma. A Case Report

Spindle cell lipoma is a distinct type of lipoma characterized by replacement of mature fat by collagen forming spindle cells. It is a benign lesion occurring chiefly in males older than 45 years and affects the subcutaneous tissues in the regions of the shoulder and posterior neck. Deep-seated (intramuscular) spindle cell lipomas are probably uncommon tumors and to date only two cases have been reported in the literature. A new case of a vascular variant of spindle cell lipoma in an intramuscular (subfascial) location is presented and the differential diagnosis is discussed.

脂肪腫ならびに脂肪腫様病変の臨床病理学的検討

The lipoma is a rare intraoral tumor, although it occurs almost anywhere on the body. We reported clinico-pathological examination in 15 cases of lipoma and 2 cases of lipoma like lesion (herniation of buccal fat pad) during the past 28 years and 7 months from January 1961 to July 1989. 15 cases of lipoma were separated 10 cases of superficial type from 5 cases of diffuse type. 15 cases of lipoma were clinico-pathologicaly similar to those described in the past reports. Results obtained were as follows: 1) The lipoma patient age ranged from 19 to 70 years and the average age was 53. 1 years. On the other hand the age of herniation of buccal fat pad patient was infant in 2 cases. 2) In lipoma, 8 cases were male and 7 cases were female. Both herniation of buccal fat pad cases were female. 3) Lipoma in 6 cases appeared in the buccal mucosa, 3 in the tongue, 3 in the lip, in the oral floor, and in the mucogingival junction. 4) The duration of symptoms in lipoma ranged from 5 days to 16 years, but on the other hand the duration of symptoms in herniation of buccal fat pad ranged from 3 days to 2 days. 5) The average size of lipoma and herniation of buccal fat pad was both about 20 mm in diameter. 6) Superficial type of lipoma which was yellowish, and pedunclated with a clear border was more easily diagnosed than diffuse type of lipoma which was normal mucosa color and had a vague border. 7) 12 tumors were histologically diagnosed as lipoma, 3 as fibrolipoma.

舌に発生した筋肉内脂肪腫

Intramuscular lipoma is an uncommon benign tumor that characteristically infiltrates skeletal muscle, while common lipomas are usually encapsulated.This uncommon type of lipoma occurring in the oral cavity is quite rare. In this paper, we report an intramuscular lipoma in the tongue of a 56-year-old woman. A pale yellow mass consisted of mature adipose cells surrounding and separating irregular bundles of the muscle. Electron microscopic examination revealed that the tumor was composed mainly of univacuolar adipocytes. No young forms of adipocytic differentiation were seen in this tumor, but occasional primitive mesenchymal cells contained a few lipid vacuoles located in penvascular area.These findings suggest that intramuscular lipoma may arise from a primitive perivascular mesenchymal cell.

Diffuse infiltrating lipomatosis. A subentity of intrapelvic fatty tumor

Nineteen patients with various types of lipoma in the pelvis are described. Clinical findings, radiological examinations, and follow-up studies constitute a particular type of lipoma, diffuse infiltrating lipomatosis; this can be distinguished from other fatty tumours because of its localisation, extent, therapeutic results and long course. Computed tomography enables us to differentiate simple lipomatosis pelvis from diffuse infiltrating lipomatosis. Histological examination is essential for excluding a liposarcoma. Growth or malignant change of diffuse infiltrating lipomatosis is most easily recognized by computed tomographic serial observation.

Myxoid lipoma of oral soft tissue: A clinical and ultrastructural study

Myxoid lipoma is an unusual histologic type of lipoma. This article reports four cases of myxoid lipoma that arose in the mouth. In frozen sections stained with oil red O, the cytoplasm of tumor cells stained strongly positive. Intercellular mucoid material was PAS-positive and diastase-resistant. It also stained positively with alcian blue. Electron microscopic observations revealed that adipocytes were in different stages of differentiation, with lipid globules of variable size observed in the cytoplasm. Many pinocytotic vesicles appeared at the plasma membrane. Mature adipocytes were surrounded by a basal lamina. Fibroblasts, collagen fibers, and mucoid material were scattered among adipocytes. It appears possible that, in the histogenesis of myxoid lipoma, multipotent mesenchymal cells undergo multidirectional differentiation. Some cells differentiate to produce mucosubstance, while others differentiate to become adipocytes.

Electroencephalographic abnormalities in homocystinuria due to cystathionine synthase deficiency

Two patients with intraspinal extradural lipomas without associated spina bifida are presented. This type of lipoma is benign and uncommon. A summary of the relevant literature is given. The clinical and myelographic differential diagnoses are discussed and a few conclusions are drawn.

Spinal extradural lipomas: Report of two cases

Two patients with intraspinal extraduralli lipomas without associated spina bifida are presented. This type of lipoma is benign and uncommon. A summary of the relevant literature is given. The clinical and myelographic differential diagnoses are discussed and a few conclusions are drawn.