Undifferentiated pleomorphic sarcoma

Undifferentiated pleomorphic sarcoma
Other namesPleomorphic myofibrosarcoma, high-grade myofibroblastic sarcoma, and high-grade myofibrosarcoma
Micrograph of undifferentiated pleomorphic sarcoma (H&E stain)
SpecialtyOncology
CausesUnknown
PrognosisGuarded
FrequencyRare

Undifferentiated pleomorphic sarcoma (UPS), also termed pleomorphic myofibrosarcoma,[1] high-grade myofibroblastic sarcoma, and high-grade myofibrosarcoma,[2] is characterized by the World Health Organization (WHO) as a rare, poorly differentiated neoplasm (i.e., an abnormal growth of cells that have an unclear identity and/or cell of origin).[3] WHO classified it as one of the undifferentiated/unclassified sarcomas in the category of tumors of uncertain differentiation.[4] Sarcomas are cancers derived mesenchymal stem cells that typically develop in bone, muscle, fat, blood vessels, lymphatic vessels, tendons, and ligaments.[5] More than 70 sarcoma subtypes have been described.[6] The UPS subtype of these sarcomas consists of tumor cells that are poorly differentiated and may appear as spindle-shaped cells, histiocytes, and giant cells.[7] UPS is considered a diagnosis that defies formal sub-classification after thorough histologic, immunohistochemical, and ultrastructural examinations fail to identify the type of cells involved.[8]

The diagnosis of UPS initially included the malignant fibrous histiocytomas (MFH).[1] MFH are now regarded as a wastebasket category of various sarcoma types including sarcoma-like carcinomas and melanomas.[9] Studies strongly suggest that MFH tumors are not derived from histiocytes (cells descended from blood monocytes),[9] but rather from mesenchymal cells.[1] UPS had also been regarded as a more aggressive and metastasizing form of the low-grade myofibroblastic sarcomas and intermediate‐grade myofibroblasic sarcomas.[1] WHO has combined low- and intermediate-grade myofibroblastic sarcomas into a single entity, low-grade myofibroblastic sarcomas, and categorized it as one type of the intermediate (rarely metastasizing) fibroblastic and myofibroblastic tumors quite distinct from UPS.[10] Because of their low incidence and frequent grouping with what are now considered to be other sarcoma types, past findings on the clinical behaviour, proper treatment, and prognosis of UPS may be revised with further study.[8]

The majority of UPS tumors are highly aggressive, often recur after surgical removal, and often metastasize.[11] They are treated with a combination of surgical resection, radiotherapy, and/or chemotherapy.[6] More recently, UPS tumors have been treated with antibody therapy, i.e. antibodies which in the case of UPS bind to specific antigens on the surface of T-cells (a type of lymphocyte) and thereby promote the ability of these T-cells to organizes an attack on UPS tumor cells.[12]

  1. ^ a b c d Fisher C (September 2004). "Myofibrosarcoma". Virchows Archiv. 445 (3): 215–23. doi:10.1007/s00428-004-1038-9. PMID 15173943. S2CID 220565385.
  2. ^ Zhao R, Wang J, Zhang H, Chi Y, Bi N (October 2020). "High-grade myofibroblastic sarcoma of the pleura: A case report and literature review". Thoracic Cancer. 11 (10): 3011–3014. doi:10.1111/1759-7714.13613. PMC 7529570. PMID 32815307.
  3. ^ Renn A, Adejolu M, Messiou C, Bhaludin B, Strauss DC, Thway K, Moskovic E (December 2021). "Overview of malignant soft-tissue sarcomas of the limbs". Clinical Radiology. 76 (12): 940.e1–940.e16. doi:10.1016/j.crad.2021.08.011. PMID 34607656. S2CID 238357489.
  4. ^ Choi JH, Ro JY (January 2021). "The 2020 WHO Classification of Tumors of Soft Tissue: Selected Changes and New Entities". Advances in Anatomic Pathology. 28 (1): 44–58. doi:10.1097/PAP.0000000000000284. PMID 32960834. S2CID 221862064.
  5. ^ "What Is Cancer?". National Cancer Institute. 2007-09-17. Retrieved 2017-11-26.
  6. ^ a b Kamat NV, Million L, Yao DH, Donaldson SS, Mohler DG, van de Rijn M, Avedian RS, Kapp DS, Ganjoo KN (February 2019). "The Outcome of Patients With Localized Undifferentiated Pleomorphic Sarcoma of the Lower Extremity Treated at Stanford University". American Journal of Clinical Oncology. 42 (2): 166–171. doi:10.1097/COC.0000000000000496. PMID 30557163. S2CID 56178938.
  7. ^ Wang J, Dong S, Zhang J, Gao S, Li Z, Li P, Yuan J, Tian Z (2021). "Undifferentiated Pleomorphic Sarcoma with Neoplastic Fever: A Retrospective Study". Cancer Management and Research. 13: 8481–8487. doi:10.2147/CMAR.S339278. PMC 8592396. PMID 34795527.
  8. ^ a b Lee K, Song JS, Kim JE, Kim W, Song SY, Lee MH, Chung HW, Cho KJ, Lee JS, Ahn JH (July 2020). "The clinical outcomes of undifferentiated pleomorphic sarcoma (UPS): A single-centre experience of two decades with the assessment of PD-L1 expressions". European Journal of Surgical Oncology. 46 (7): 1287–1293. doi:10.1016/j.ejso.2020.02.029. PMID 32127249. S2CID 212406069.
  9. ^ a b Hornick JL (January 2020). "Cutaneous soft tissue tumors: how do we make sense of fibrous and "fibrohistiocytic" tumors with confusing names and similar appearances?". Modern Pathology. 33 (Suppl 1): 56–65. doi:10.1038/s41379-019-0388-4. PMID 31653978. S2CID 204886468.
  10. ^ Sbaraglia M, Bellan E, Dei Tos AP (April 2021). "The 2020 WHO Classification of Soft Tissue Tumours: news and perspectives". Pathologica. 113 (2): 70–84. doi:10.32074/1591-951X-213. PMC 8167394. PMID 33179614.
  11. ^ Widemann BC, Italiano A (January 2018). "Biology and Management of Undifferentiated Pleomorphic Sarcoma, Myxofibrosarcoma, and Malignant Peripheral Nerve Sheath Tumors: State of the Art and Perspectives". Journal of Clinical Oncology. 36 (2): 160–167. doi:10.1200/JCO.2017.75.3467. PMC 5759316. PMID 29220302.
  12. ^ Tawbi HA, Burgess M, Bolejack V, Van Tine BA, Schuetze SM, Hu J, D'Angelo S, Attia S, Riedel RF, Priebat DA, Movva S, Davis LE, Okuno SH, Reed DR, Crowley J, Butterfield LH, Salazar R, Rodriguez-Canales J, Lazar AJ, Wistuba II, Baker LH, Maki RG, Reinke D, Patel S (November 2017). "Pembrolizumab in advanced soft-tissue sarcoma and bone sarcoma (SARC028): a multicentre, two-cohort, single-arm, open-label, phase 2 trial". The Lancet. Oncology. 18 (11): 1493–1501. doi:10.1016/S1470-2045(17)30624-1. PMC 7939029. PMID 28988646.