Mast Cell Sarcoma


Mast cell sarcoma is a rare tumor that may present in many different anatomic locations and age groups, and prognosis is generally poor. Mast cell sarcoma is often misdiagnosed because the presenting cells bear little resemblance to normal mast cells and spindle-shaped mast cells frequently seen in systemic mastocytosis.3 The cells of mast cell sarcoma more closely resemble “atypical type II mast cells” or “promastocytes” that are associated with some cases of aggressive systemic mastocytosis.1, 3 Pathological examination of the tumor has shown it to be highly malignant with an aggressive growth pattern.3, 4 Patients with this tumor do not fulfill the criteria for SM.1 The imatinib mesylate-resistant KIT D816V mutation has not been found in reported mast cell sarcomas, such that use of imatinib has been attempted in some patients.3


  1. Valent P, Horny HP, Escribano L, Longley BJ, Li CY, Schwartz LB, et al. Diagnostic criteria and classification of mastocytosis: a consensus proposal. Leuk Res. 2001 Jul;25(7):603-25.
  2. Horny HP, Akin C, Metcalfe DD, Escribano L, Bennett JM, Valent P, et al. Mastocytosis (mast cell disease) Swerdlow SH, Campo E, Harris NL, Jaffe ES, Pileri SA, Stein H, et al., editors. World Health Organization (WHO) Classification of Tumours. Pathology and Genetics. Tumours of Haematopoietic and Lymphoid Tissues. Lyon: IARC Press; 2008.
  3. Ryan RJ, Akin C, Castells M, Wills M, Selig MK, Nielsen GP, et al. Mast cell sarcoma: a rare and potentially under-recognized diagnostic entity with specific therapeutic implications. Mod Pathol. 2013 Apr;26(4):533-43.
  4. Georgin-Lavialle S, Aguilar C, Guieze R, Lhermitte L, Bruneau J, Fraitag S, et al. Mast cell sarcoma: a rare and aggressive entity–report of two cases and review of the literature. J Clin Oncol. 2013 Feb 20;31(6):e90-7.
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