Desmoplastic myxoid tumor of the pineal region, SMARCB1-mutant
Citation, DOI & article data
Desmoplastic myxoid tumor of the pineal region, SMARCB1-mutant is a rare and recently described type of pineal parenchymal tumor encountered in adults.
Desmoplastic myxoid tumor of the pineal gland SMARCB1-mutant occurs in adolescents and young adults (mean age of diagnosis 40 years old) with a slight predominance in females (M:F ratio of 3:4)1.
Its characteristics are still uncertain since the number of cases is limited. Desmoplastic myxoid tumor of the pineal gland SMARCB1-mutant shares with atypical teratoid/rhabdoid tumors (AT/RT) the mutation of the SMARCB1 gene, although it has different histopathological and clinical features 1,2.
Desmoplastic myxoid tumor of the pineal gland SMARCB1-mutant usually demonstrates spindled and epithelioid cells in a desmoplastic stroma alternating with a myxoid matrix. Unlike atypical teratoid/rhabdoid tumors, it does not present brisk mitotic activity and necrosis 1,2.
Similarly to atypical teratoid/rhabdoid tumors, desmoplastic myxoid tumor of the pineal gland SMARCB1-mutant displays loss of nuclear SMARCB1/INI1 protein expression. Ki-67 index ranges from 2% to 15% 1.
Desmoplastic myxoid tumor of the pineal gland SMARCB1-mutant is indistinguishable from other pineal tumors 2,3.
- T1: hypointense
- T2/FLAIR: hyperintense
- T1 C+ (Gd): strong enhancement
Treatment and prognosis
Data about treatment and prognosis of the SMARCB1-mutant type of tumor are still limited. Surgical resection is the treatment of choice. Chemotherapy and radiotherapy have been employed in some cases 2.
The differential diagnosis generally includes other pineal parenchymal tumors.
- 1. Matsumura N, Goda N, Yashige K et al. Desmoplastic Myxoid Tumor, SMARCB1-Mutant: A New Variant of SMARCB1-Deficient Tumor of the Central Nervous System Preferentially Arising in the Pineal Region. Virchows Arch. 2021;479(4):835-9. doi:10.1007/s00428-020-02978-3 - Pubmed
- 2. Thomas C, Wefers A, Bens S et al. Desmoplastic Myxoid Tumor, SMARCB1-Mutant: Clinical, Histopathological and Molecular Characterization of a Pineal Region Tumor Encountered in Adolescents and Adults. Acta Neuropathol. 2019;139(2):277-86. doi:10.1007/s00401-019-02094-w - Pubmed
- 3. Desmoplastic Myxoid Tumor of Pineal Region, SMARCB1-Mutant, in Young Adult. Free Neuropathology. 2:14. doi:10.17879/freeneuropathology-2021-3340