[Lipoma and atypical lipomatous tumor within the same neoplasia: Evidence for a continuous transition].
The case of a lipomatous tumor with a predominant lipoma component and transition to an atypical lipomatous tumor is presented. A deep-seated soft tissue tumor of the right thigh with a maximum size of 14 cm was resected in a 70-year-old female patient. Corresponding to a comparable macroscopic aspect, the lesion revealed the histological features of an ordinary lipoma without atypia in about 80% of the specimen. In the remaining portion (approximately 20%) histopathology showed an atypical lipomatous tumor (ALT, lipoma-like subtype). Immunohistochemistry for MDM 2 and CDK4 revealed no immunoreactivity in the lipoma component, but within the ALT component. Interphase dual-color fluorescence in situ hybridization showed no amplification of the MDM 2 gene and rarely CDK4 gene amplification within the lipoma component, but high level amplification of MDM 2/CDK4 gene in the ALT area, further supporting the morphologically based diagnosis of a lipomatous tumor including areas of a true lipoma and ALT. This case underlines the concept of a continuous stepwise development of lipomatous soft tissue tumors from benign to malignant counterparts as a biological continuum.
Kuhnen
C
C
Institut für Pathologie am Clemenshospital, Medical Center, Münster, Düesbergweg 128, 48153 Münster. kuhnen@patho-muenster.de
Mentzel
T
T
Lehnhardt
M
M
Homann
H H
HH
Sciot
R
R
Debiec-Rychter
M
M
D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000473:pathology*; D051358:Cyclin-Dependent Kinase 4 / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008067:Lipoma / Q000235:genetics / Q000473:pathology*; D008080:Liposarcoma / Q000235:genetics / Q000473:pathology*; D051736:Proto-Oncogene Proteins c-mdm2 / Q000235:genetics; D012983:Soft Tissue Neoplasms / Q000235:genetics / Q000473:pathology*; D013848:Thigh
D014408:Biomarkers, Tumor; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2; C495900:CDK4 protein, human; D051358:Cyclin-Dependent Kinase 4