Abstract
Atypical and malignant lipomatous tumors are infrequent in the pediatric population. Within this uncommon cohort, the morphologically and genetically related spectrum of atypical lipomatous tumor/well-differentiated liposarcoma/dedifferentiated liposarcoma (ALT/WDL/DDLS) is markedly rare. Their shared characteristic molecular aberration is a genomic amplicon of a region of chromosome 12q, including the oncogenes MDM2 and CDK4. We present an unusual case of a pediatric patient with an ALT, with recurrence after 2 years in the form of a bone-forming mass, radiologically and pathologically mimicking parosteal osteosarcoma, a tumor also molecularly characterized by amplification of MDM2 and CDK4. However, with ample histologic sampling, a single focus of lipogenic differentiation was identified, thus representing the first near complete low-grade osteosarcomatous dedififferentation reported within ALT/WDL/DDLS and the first ever in pediatric patient. The case serves a reminder of a diagnosis differential and pitfalls within MDM2-amplified tumors.
Original language | English (US) |
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Pages (from-to) | 240-246 |
Number of pages | 7 |
Journal | Pediatric and Developmental Pathology |
Volume | 23 |
Issue number | 3 |
DOIs | |
State | Published - Jun 1 2020 |
Keywords
- MDM2
- atypical lipomatous tumor
- liposarcoma
- osteosarcoma
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health
- Pathology and Forensic Medicine