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Jason L. Hornick - One of the best experts on this subject based on the ideXlab platform.
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S-100 protein expressing spindle cells in spindle cell Lipoma: a diagnostic pitfall
Virchows Archiv, 2016Co-Authors: Thomas Mentzel, Arno Rütten, Markus Hantschke, Jason L. Hornick, Thomas BrennAbstract:Spindle cell Lipoma represents a distinct clinicopathological entity and is related to cellular angiofibroma and mammary-type myofibroblastoma. Spindle cell Lipomas are composed of mature lipogenic cells and a variable number of CD34-positive spindle cells that show loss of retinoblastoma protein expression. Spindle cell Lipomas occasionally express S-100 protein. We studied one case of purely dermal spindle cell Lipoma and four cases of classical subcutaneous spindle cell Lipoma arising in one female and four male patients (age ranged from 55 to 69 years). The neoplasms arose on the nose, the chin, the neck, the forehead and retroauricular, and all lesions had been marginally or incompletely excised. The studied cases showed classical histological and immunohistochemical features of spindle cell Lipoma and, in addition, strong expression of S-100 protein by spindle-shaped tumour cells. S-100-expression in spindle cell Lipoma may cause problems in the differential diagnosis with neural and melanocytic neoplasms and emphasizes the plasticity of the spindle cells in spindle cell Lipoma.
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spindle cell pleomorphic Lipomas of the face an under recognized diagnosis
Histopathology, 2015Co-Authors: Alison L Cheah, Jason L. Hornick, Steven D Billings, John R Goldblum, Nasir Uddin, Brian P RubinAbstract:Aims: Rarely, spindle cell/pleomorphic Lipomas ariseon the face where they present diagnostic difficulties.The aim of our study was to describe the clinical,histological and immunohistochemical features of aseries of spindle cell/pleomorphic Lipomas of the face.Methods and results: Thirty-three cases of spindle cell/pleomorphic Lipoma of the face were studied. Patientcharacteristics were 25 male:8 female, ranging from33 to 91 years of age (mean 60). The most commonsites were nose (nine), cheek (eight), forehead (eight),chin (three), anterior scalp (three), lip (two) and ear(two). The mean tumour size was 1.9 cm. An unusualhistological feature was the involvement of skeletalmuscle, which was seen in 12 cases (36%). Otherwise,the cases exemplified the entire histological spectrumof spindle cell Lipoma, including purely dermal and sub-cutaneous cases. By immunohistochemistry, they wereuniformly positive for CD34 (26 of 26 cases), positivefor oestrogen receptor in five of 21 cases and negativefor desmin in all cases (none of 20 positive). Retino-blastoma (Rb) expression was lost in 18 of 19 cases.Conclusions: Due to an unusual anatomical locationand frequent infiltration of skeletal muscle, spindlecell/pleomorphic Lipoma of the face can be a difficultdiagnosis. Increased awareness of its clinicopathologi-cal features should allow accurate classification.Keywords: diagnosis, face, pleomorphic Lipoma, spindle cell Lipoma
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loss of retinoblastoma protein expression in spindle cell pleomorphic Lipomas and cytogenetically related tumors an immunohistochemical study with diagnostic implications
The American Journal of Surgical Pathology, 2012Co-Authors: Benjamin J Chen, Adrian Marinoenriquez, Christopher D M Fletcher, Jason L. HornickAbstract:Consistent rearrangements of chromosomes 13q and 16q have been identified in spindle cell and pleomorphic Lipomas by cytogenetics. Mammary-type myofibroblastoma and cellular angiofibroma show overlapping histologic features and similar chromosomal losses, suggesting a possible relationship among these tumor types. The tumor suppressor gene RB1, encoding the retinoblastoma (Rb) protein, is located at 13q14, within a minimally deleted region in spindle cell Lipoma. The purpose of this study was to examine expression of Rb by immunohistochemistry in spindle cell Lipoma, pleomorphic Lipoma, mammary-type myofibroblastoma, and cellular angiofibroma, and in histologic mimics, to determine its potential diagnostic utility. Whole-tissue sections of 194 tumors were evaluated: 18 spindle cell Lipomas, 20 pleomorphic Lipomas, 19 mammary-type myofibroblastomas, 16 cellular angiofibromas, 22 conventional Lipomas (8 intramuscular), 18 atypical Lipomatous tumors (all positive for MDM2 and CDK4), 19 solitary fibrous tumors, 19 myxoid liposarcomas, 14 hibernomas, 11 deep (aggressive) angiomyxomas, 9 angiomyofibroblastomas, and 9 vulval fibroepithelial stromal polyps. Immunohistochemistry was performed after pressure cooker antigen retrieval using a mouse anti-Rb monoclonal antibody. Nuclear staining for Rb was scored as "intact" or "deficient." Rb expression was deficient in all spindle cell Lipomas, pleomorphic Lipomas, and cellular angiofibromas and in 17 (89%) mammary-type myofibroblastomas. Rb staining was sometimes difficult to interpret in cellular angiofibromas with reactive stromal changes. Rb was also deficient in 2 (9%) conventional Lipomas. Rb expression was intact in all other tumor types evaluated. In summary, of the soft tissue tumors associated with 13q deletions, all spindle cell Lipomas, pleomorphic Lipomas, and cellular angiofibromas and most mammary-type myofibroblastomas show loss of Rb expression. Rb expression is intact in histologic mimics. These findings reinforce the pathogenetic relationship among this group of tumors and demonstrate the potential diagnostic utility of immunohistochemistry for Rb.
Petur G Nielsen - One of the best experts on this subject based on the ideXlab platform.
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dysplastic Lipoma potential diagnostic pitfall of using mdm2 rna in situ hybridization to distinguish between Lipoma and atypical Lipomatous tumor
Human Pathology, 2020Co-Authors: Yin P Hung, Michael Michal, Adrian M Dubuc, Andrew E Rosenberg, Petur G NielsenAbstract:Summary The distinction between Lipoma and atypical Lipomatous tumor can be challenging in some cases. While detection of MDM2 gene amplification via fluorescence in situ hybridization (FISH) has been well established as a diagnostic tool to distinguish atypical Lipomatous tumor and well-differentiated liposarcoma from benign mimics, MDM2 RNA in situ hybridization (RNA-ISH) has recently been proposed as an alternative diagnostic assay. During clinical workup for Lipomatous tumors using MDM2 RNA-ISH, we noticed several dysplastic Lipomas that were positive for MDM2 RNA-ISH but negative for MDM2 amplification by FISH. In this study, we examined a series of 11 dysplastic Lipomas, all confirmed to be negative for MDM2 amplification by FISH. Positive MDM2 RNA-ISH was noted in 10 (91%) dysplastic Lipomas. Single-nucleotide polymorphism array on one dysplastic Lipoma identified the presence of homozygous deletion of 13q, including the RB1 gene locus with no evidence of MDM2 copy number gain. Our findings on the discordance between MDM2 FISH and MDM2 RNA-ISH highlight the potential utility and pitfalls of using MDM2 RNA-ISH in the distinction of atypical Lipomatous tumor and related liposarcomas from dysplastic Lipoma.
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mdm2 rna in situ hybridization for the diagnosis of atypical Lipomatous tumor a study evaluating dna rna and protein expression
The American Journal of Surgical Pathology, 2019Co-Authors: Anupriya S Kulkarni, John Wojcik, Abhijit Chougule, Kshitij S Arora, Yashaswini Chittampalli, Pawel Kurzawa, John T Mullen, Ivan Chebib, Petur G Nielsen, Miguel RiveraAbstract:The distinction of atypical Lipomatous tumor/well-differentiated liposarcoma (ALT/WDL) from its benign counterpart, Lipoma, may represent a challenge. MDM2 DNA amplification is used as the gold standard as MDM2 immunohistochemistry lacks specificity and sensitivity. Herein, we investigate the diagnostic utility of MDM2 RNA in situ hybridization (RNA-ISH) and compare the test with MDM2 immunohistochemistry and MDM2 DNA fluorescence in situ hybridization (FISH) in benign and malignant Lipomatous neoplasms. We evaluated 109 neoplasms including 27 Lipomas, 25 spindle cell Lipomas, 32 ALTs/WDLs, and 25 dedifferentiated liposarcomas (DDL). The validation cohort included 14 Lipoma-like neoplasms that lacked unequivocal features of ALT/WDL and in which MDM2 immunohistochemistry was either equivocal, negative or falsely positive. Immunohistochemistry, automated RNA-ISH and DNA-FISH for MDM2 were performed. Tumors with diffuse nuclear staining or >50 dots per cell on RNA-ISH were considered positive. All Lipomas and Lipoma variants were negative for RNA-ISH while all ALTs/WDLs and DDLs were positive. Eighty percent (24/30) and 92% (22/24) of ALTs/WDLs and DDLs were positive for MDM2 immunohistochemistry. Lipomas and its variants were negative for MDM2 amplification; 92% and 100% of ALTs/WDLs and DDLs showed MDM2 DNA amplification. The mean percentage of ALT/WDL tumor cells showing MDM2 RNA-ISH positivity was 73% compared with 24% on MDM2 immunohistochemistry. RNA-ISH correctly classified all 10 ALTs/WDLs and all 4 Lipomas in the validation cohort. The performance of MDM2 RNA-ISH and MDM2 DNA-FISH are equivalent. MDM2 RNA-ISH can be of diagnostic value in histologically challenging Lipomatous neoplasms. The automated MDM2 RNA-ISH assay should allow for more widespread use of MDM2 testing and for a more sensitive and specific diagnosis of ALT/WDL.
Brian P Rubin - One of the best experts on this subject based on the ideXlab platform.
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spindle cell pleomorphic Lipomas of the face an under recognized diagnosis
Histopathology, 2015Co-Authors: Alison L Cheah, Jason L. Hornick, Steven D Billings, John R Goldblum, Nasir Uddin, Brian P RubinAbstract:Aims: Rarely, spindle cell/pleomorphic Lipomas ariseon the face where they present diagnostic difficulties.The aim of our study was to describe the clinical,histological and immunohistochemical features of aseries of spindle cell/pleomorphic Lipomas of the face.Methods and results: Thirty-three cases of spindle cell/pleomorphic Lipoma of the face were studied. Patientcharacteristics were 25 male:8 female, ranging from33 to 91 years of age (mean 60). The most commonsites were nose (nine), cheek (eight), forehead (eight),chin (three), anterior scalp (three), lip (two) and ear(two). The mean tumour size was 1.9 cm. An unusualhistological feature was the involvement of skeletalmuscle, which was seen in 12 cases (36%). Otherwise,the cases exemplified the entire histological spectrumof spindle cell Lipoma, including purely dermal and sub-cutaneous cases. By immunohistochemistry, they wereuniformly positive for CD34 (26 of 26 cases), positivefor oestrogen receptor in five of 21 cases and negativefor desmin in all cases (none of 20 positive). Retino-blastoma (Rb) expression was lost in 18 of 19 cases.Conclusions: Due to an unusual anatomical locationand frequent infiltration of skeletal muscle, spindlecell/pleomorphic Lipoma of the face can be a difficultdiagnosis. Increased awareness of its clinicopathologi-cal features should allow accurate classification.Keywords: diagnosis, face, pleomorphic Lipoma, spindle cell Lipoma
Takashi Satoh - One of the best experts on this subject based on the ideXlab platform.
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imaging characteristics of deep seated Lipomatous tumors intramuscular Lipoma intermuscular Lipoma and Lipoma like liposarcoma
Journal of Orthopaedic Science, 2007Co-Authors: Jun Nishida, Hiroshi Orui, Hiroshi Kakizaki, Tetsuro Morita, Masahito Hatori, Takahiro Tajino, Kyoji Okada, Shigeru Ehara, Akira Ogose, Takashi SatohAbstract:Background Lipoma-like liposarcomas mimic deep-seated Lipomas in regard to imaging as well as histological findings and occasionally cause problems concerning diagnosis and treatment. The differences in the imaging findings among these lesions are not well defined. The purpose of this study was to elucidate the differences among the deep-seated adipocytic neoplasms including intramuscular Lipoma, intermuscular Lipoma, and Lipoma-like liposarcoma.
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imaging characteristics of deep seated Lipomatous tumors intramuscular Lipoma intermuscular Lipoma and Lipoma like liposarcoma
Journal of Orthopaedic Science, 2007Co-Authors: Jun Nishida, Hiroshi Orui, Hiroshi Kakizaki, Tetsuro Morita, Masahito Hatori, Takahiro Tajino, Kyoji Okada, Shigeru Ehara, Akira Ogose, Takashi SatohAbstract:Abstract Background Lipoma-like liposarcomas mimic deep-seated Lipomas in regard to imaging as well as histological findings and occasionally cause problems concerning diagnosis and treatment. The differences in the imaging findings among these lesions are not well defined. The purpose of this study was to elucidate the differences among the deep-seated adi-pocytic neoplasms including intramuscular Lipoma, intermuscular Lipoma, and Lipoma-like liposarcoma. Methods The imaging and clinicopathological findings of 40 intramuscular Lipomas, 27 intermuscular Lipomas, and 22 Lipoma-like liposarcomas were evaluated, and the possibilities in the differential diagnosis were assessed. Results Although the most frequent symptom was a palpable mass, swelling was a common symptom of intramuscular Lipomas and Lipoma-like liposarcomas. Imaging studies revealed dumbbell-shaped appearances among intermuscular Lipomas, whereas spherical masses were characteristic of intramuscular Lipomas and Lipoma-like liposarcomas. Computed tomography and magnetic resonance imaging revealed fatty lesions containing streaky structures in benign lesions, and CT revealed foci of hazy amorphous density, representing spindle cell proliferation, in Lipoma-like liposarcoma. Although streaky structures corresponding to entrapped muscle fibers were thick and occasionally interrupted in intramuscular Lipomas, the streaky structures corresponding to areolar fibrous tissue were thin and were usually not interrupted in intermuscular Lipomas. In Lipoma-like well-differentiated liposarcomas, thick streaks represented entrapped muscle fibers, and thin streaks represented fibrous tissue or neoplastic spindle cell proliferation. Conclusions The imaging findings are helpful and often afford almost pathognomonic evidence of these lesions and could help with the selection of appropriate surgery.
Armando Cama - One of the best experts on this subject based on the ideXlab platform.
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Spinal Lipoma as a dysembryogenetic anomaly: Four unusual cases of ectopic iliac rib within the spinal Lipoma.
Birth defects research. Part A Clinical and molecular teratology, 2016Co-Authors: Andrea Accogli, Marco Pavanello, Patrizia Accorsi, Patrizia De Marco, Elisa Merello, Mattia Pacetti, Paolo Nozza, Chiara Fiorillo, Lorenzo Pinelli, Armando CamaAbstract:Background Congenital spinal Lipomas are closed spinal dysraphisms belonging to the neural tube defects (NTDs) group. They include a broad spectrum of lesions ranging from simple Lipomas of the filum terminale to complex malformations. On histological evaluation, various tissue components of ectodermal, mesodermal or endodermal origin are found within the Lipomas, with prevalence for nerves and striated muscle and, more rarely, cartilage and bone. Overall, rib malformations have been occasionally observed in patients with NTDs and in NTD mouse models. However, an ectopic rib arising within the spinal Lipoma and articulating with the iliac crest has not been reported in either animal models or in humans. Cases We describe four patients affected by lipomyeloschisis or lipomyelomeningocele, with an unusual fibrocartilaginous protuberance arising within the Lipoma and connecting to one iliac crest, strongly resembling an ectopic rib. Histological evaluation confirmed the presence of cartilaginous tissue. Conclusion We expand the clinical spectrum of fibrocartilaginous anomalies associated with spinal Lipoma, suggesting the presence of an ectopic rib as a new possible phenotype in NTDs. A careful analysis by neuroradiologists and pathologists should be performed in spinal Lipomas to assess the presence of an ectopic rib or other uncommon developmental anomalies. Furthermore, molecular studies are required to detect the genetic cause of this unusual phenotype. Birth Defects Research (Part A) 106:530–535, 2016. © 2016 Wiley Periodicals, Inc.