Retroperitoneal undifferentiated pleomorphic sarcoma having microsatellite instability associated with Muir-Torre syndrome: case report and review of literature.

Abstract

Muir-Torre syndrome represents a rare autosomal dominant familial cancer predisposition disorder defined by the occurrence of cutaneous sebaceous tumors and an internal malignancy, most commonly gastrointestinal carcinoma. Most examples of hereditary non-polyposis cancer syndrome (Lynch syndrome), including the Muir-Torre syndrome, are associated with microsatellite instability (MSI) and germline mutations in mismatch repair genes-most commonly MLH1 or MSH2. We present a 58-year-old man with Muir-Torre syndrome and a large retroperitoneal mass (14.3 cm in greatest dimension) encompassing the left adrenal gland. Sections showed a cellular malignant tumor composed of spindle cells with a high mitotic index and lacking morphologic evidence of adipocytic differentiation. It was weakly reactive for smooth muscle actin (SMA) and negative for desmin, CD117, CD31, CD34, S100 protein and pan-cytokeratin. Further immunohistochemical analysis revealed intact expression of MLH1 but loss of MSH2 in tumor nuclei. Compared to non-neoplastic tissue, the tumor showed MSI in five of seven dinucleotide markers. Fluorescence in situ hybridization (FISH) failed to reveal 12q15 amplification, effectively excluding dedifferentiated liposarcoma as a diagnostic consideration. This is a rare case of a patient with Muir-Torre syndrome who developed a related high-grade undifferentiated pleomorphic sarcoma as the associated internal malignancy.

• Authors: Nathan Lee, Rajyalakshmi Luthra, Dolores Lopez-Terrada, Wei-Lien Wang, Alexander J Lazar
• Journal: Journal of cutaneous pathology (J Cutan Pathol) Vol. 40 Issue 8 Pg. 730-3 (Aug 2013) ISSN: 1600-0560 [Electronic] United States
• PMID: 23672746 (Publication Type: Case Reports, Journal Article, Review)
• Copyright: © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Chemical References

• Adaptor Proteins, Signal Transducing
• Antigens, CD
• MLH1 protein, human
• Nuclear Proteins
• S100 Proteins
• MSH2 protein, human
• MutL Protein Homolog 1
• MutS Homolog 2 Protein

Topics

• Adaptor Proteins, Signal Transducing (genetics, metabolism)
• Antigens, CD (genetics, metabolism)
• Chromosomal Instability
• Germ-Line Mutation
• Humans
• Male
• Microsatellite Repeats
• Middle Aged
• Muir-Torre Syndrome (genetics, metabolism, pathology)
• MutL Protein Homolog 1
• MutS Homolog 2 Protein (genetics, metabolism)
• Neoplasms, Second Primary (metabolism, pathology)
• Nuclear Proteins (genetics, metabolism)
• Retroperitoneal Neoplasms (pathology)
• S100 Proteins (genetics, metabolism)
• Sarcoma (genetics, metabolism, pathology)