Olıgosarcoma: A Rare Case Report Wıth Dıstınct Features.

Area of Science:

• Neuro-oncology
• Surgical pathology
• Molecular diagnostics

Background:

• Oligosarcoma is a rare entity characterized by sarcomatous transformation of an oligodendroglioma.
• Sarcomatous components are infrequently observed in glial tumors, with rare mentions in the World Health Organization (WHO) classification of grade 3 oligodendrogliomas.

Purpose of the Study:

• To report a case of oligosarcoma in a 42-year-old male patient.
• To detail the histomorphological, immunohistochemical, and molecular findings of this rare tumor.

Main Methods:

• Histopathological and histochemical (reticulin staining) evaluation of the recurrent tumor.
• Immunohistochemical analysis for p53 and OLIG2 expression.
• Molecular analysis for IDH, TERT mutations, and 1p/19q and CDKN2A deletions.

Main Results:

• The recurrent lesion showed distinct glial and sarcomatous components, confirming oligosarcoma.
• The sarcomatous component expressed p53 and OLIG2.
• Molecular analysis revealed IDH and TERT mutations, along with 1p/19q and CDKN2A deletions.

Conclusions:

• This case contributes to the understanding of oligosarcoma, a rare glial tumor with sarcomatous differentiation.
• The distinct histopathological and molecular profile, including specific mutations and deletions, aids in the diagnosis and characterization of oligosarcoma.