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Myxoid Inflammatory Myofibroblastic Sarcoma: Clinicopathologic Analysis of 25 Cases of a Distinctive Sarcoma With Deceptively Bland Morphology and Aggressive Clinical Behavior.
- Source :
-
The American journal of surgical pathology [Am J Surg Pathol] 2024 Aug 01; Vol. 48 (8), pp. 1005-1016. Date of Electronic Publication: 2024 May 08. - Publication Year :
- 2024
-
Abstract
- The number of recognized sarcoma types harboring targetable molecular alterations continues to increase. Here we present 25 examples of a distinctive myofibroblastic tumor, provisionally termed "myxoid inflammatory myofibroblastic sarcoma," which might be related to inflammatory myofibroblastic tumor, and which occurred in 13 males (52%) and 12 females at a median age of 37 years (range: 7 to 79 years). Primary tumor sites were peritoneum (18 patients; 72%), paratesticular (2; 8%), chest wall (1), upper extremity (1), esophagus (1), retroperitoneum (1), and uterus (1). Nine peritoneal tumors (50%) were multifocal at presentation; all other tumors were unifocal. Tumors showed bland-to-mildly-atypical neoplastic myofibroblasts in a myxoid stroma, with prominent inflammatory infiltrates in 22 cases (88%). Most tumors showed delicate branching stromal vessels like those of myxoid liposarcoma, and most showed infiltrative growth through non-neoplastic tissue. Immunohistochemistry demonstrated expression of SMA (19/25 tumors; 76%), desmin (13/22; 59%), and CD30 (5/11; 45%), while ALK was expressed in 1 tumor (of 25; 4%) that was negative for ALK rearrangement. Sequencing of 11 tumors showed seven to harbor tyrosine kinase fusions (4 PDGFRB , 2 PML :: JAK1 , 1 SEC31A :: PDGFRA ). Two instead harbored hot spot KRAS mutations (G12V and Q61H), and 2 were negative for known driving alterations. Clinical follow-up was available for 18 patients (72%; median: 2.7 years; range: 4 mo-12.3 years). Nine patients (50%) were alive with no evidence of disease, 5 (28%) died of disease, and 4 (22%) were alive with disease. Seven patients (39%) experienced peritoneal relapse or distant metastasis. Two patients showed disease progression on conventional, nontargeted chemotherapy. The patient whose tumor harbored SEC31A :: PDGFRA was treated after multiple relapses with imatinib and sunitinib therapy, with progression-free periods of 5 and 2 years, respectively. Despite its bland appearance, myxoid inflammatory myofibroblastic sarcoma harbors a significant risk for disseminated disease, particularly when it occurs in the peritoneum. Targeted therapy could be considered for patients with disseminated disease.<br />Competing Interests: Conflicts of Interest and Source of Funding: The authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article.<br /> (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)
- Subjects :
- Humans
Male
Female
Adult
Middle Aged
Aged
Adolescent
Young Adult
Child
Soft Tissue Neoplasms pathology
Soft Tissue Neoplasms genetics
Soft Tissue Neoplasms mortality
Soft Tissue Neoplasms therapy
Sarcoma pathology
Sarcoma genetics
Sarcoma chemistry
Sarcoma mortality
Immunohistochemistry
Biomarkers, Tumor genetics
Biomarkers, Tumor analysis
Myofibroblasts pathology
Myofibroblasts chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 1532-0979
- Volume :
- 48
- Issue :
- 8
- Database :
- MEDLINE
- Journal :
- The American journal of surgical pathology
- Publication Type :
- Academic Journal
- Accession number :
- 38717131
- Full Text :
- https://doi.org/10.1097/PAS.0000000000002231