Smooth Muscle, Endometrial Stromal, and Mixed Müllerian Tumors of the Uterus

Biomarker resolution of uterine smooth muscle tumor necrosis as benign vs malignant

“…This is in keeping with the relative lack of inflammatory tissue response to cell death and associated retention of the native reticulin network in leiomyosarcoma. 3,5,6 These findings can be summarized in a model ( Figure 4) in which reticulin is retained in the early phases of necrosis of both leiomyomas and leiomyosarcomas. In leiomyomas the necrosis develops as a discrete event, producing a stable viable-nonviable interface that is subjected to host repair over time, including matrix remodeling, collagen deposition, and reticulin resorption.…”

“…4,[11][12][13] The robust inflammatory response to the necrotic core initiates tissue degradation and stromal matrix remodeling, resulting in the replacement of infarcted tumor by dense hyalinized tissue. 5 The nonviable regions of leiomyosarcoma tend to display preservation of preexisting vessels with a peripheral rim of viable neoplastic cells, 6 implying that ischemic injury in leiomyosarcoma is not primarily of vascular etiology, but rather a more complex process acting upon viable cells adjacent to the outer perimeter of necrosis. In contrast to leiomyomas, leiomyosarcoma overexpress markers of hypoxic stress, 9 in keeping with a chronic and ongoing state of injurious ischemia rather than the abrupt vascular events that characterize infarctions in leiomyomas.…”

“…TCN has an abrupt transition with minimal tissue reaction, while infarct type necrosis commonly exhibits inflammation, hemorrhage, and a zone of granulation/fibrous (reparative) tissue that separates the viable and nonviable areas of tumor. 5 Ghosts of individual necrotic cells are retained more commonly in TCN. Despite these specific criteria, interpretation of nonviable areas as sarcoma-specific vs nonspecific can be difficult and poorly reproducible.…”

Uterine Smooth Muscle Tumors of Uncertain Malignant Potential (STUMP): Review of Pathophysiology, Classification, Diagnosis, Treatment, and Surveillance

“…Accurately diagnosing uterine smooth muscle neoplasms is clinically significant for correct patient management. The correct diagnosis of STUMP tumors however can be challenging as many histologic characteristics overlap with rare subtypes of leiomyoma variants [2,3,19,23].…”

“…The classification of uterine smooth muscle tumors is based on the assessment of three histopathologic characteristics: Mitotic count activity or mitotic index (number of mitotic figures per 10 high power fields [hpf]), presence of coagulative tumor cell necrosis, and degree of cytological atypia [19][20][21][22]. Accurately diagnosing uterine smooth muscle neoplasms is clinically significant for correct patient management.…”