This chapter deals with neoplasms of the uterus in which there is mesenchymal differentiation. Purely mesenchymal tumors, such as those derived from smooth muscle and endometrial stroma, are considered, as are benign and malignant neoplasms in which there are mixtures of epithelium and connective tissue.

Mesenchymal Tumors of the Uterus

Background Merkel cell carcinoma (MCC) is a rare, aggressive skin cancer. Objective We sought to describe primary MCC incidence trends, epidemiology, and predictors of survival. Methods The population covered by the Surveillance, Epidemiology, and End Results Program was analyzed as a prospective cohort. We measured age-adjusted incidence rates (per 100,000 person-years) and effect of age, anatomic site, and stage on survival. Results Incidence was higher in males (0.34) than in females (0.17). Cases (n = 1034) occurred mostly in whites (94%), in people older than 65 years (76%), and at the head (48%). The 5-year relative survival was 75%, 59%, and 25% for localized, regional, and distant MCC, respectively. Female sex, limb presentation, localized disease, and younger age were positive predictors of survival. Conclusion The highest incidence of MCC was observed in whites, males, and in people older than 65 years. Only 49% of cases were reported as localized. Better survival was associated with limb localization, early-stage disease, younger age, and female sex.

https://www.jaad.org/article/S0190-9622(03)02108-X/pdf

Epidemiology of primary Merkel cell carcinoma in the United States

Merkel cell carcinoma is a malignant neuroendocrine tumor with features of epithelial differentiation. Biologically aggressive, it may be difficult to diagnose and, particularly in its late stages, even more difficult to treat effectively. This article addresses what is known and what is still controversial about the histogenesis, diagnosis, and management of Merkel cell carcinoma and the structure and function of the Merkel cell from which it is believed to be derived. The incidence, clinical presentation and diagnosis, ultrastructure, immunocytochem-istry, treatment, and prognosis of this tumor will be discussed.

Merkel cell carcinoma

Background: Merkel cell carcinoma (MCC) is an unusual and potentially aggressive cancer of the skin. There is no consensus regarding the optimal therapeutic approach, and the relative roles of surgery, radiotherapy, and chemotherapy still are controversial The aim of this study is to analyze the roles of these therapeutic options.

Multimodality treatment of Merkel cell carcinoma: case series and literature review of 1024 cases.

Mullerian adenosarcoma of the uterus: a clinicopathologic analysis of 100 cases with a review of the literature.

We report the electron microscopic studies of three trabecular carcinomas of the skin. The presence of neurosecretory granules in all three tumors suggests that trabecular carcinoma originates from one of the neurocrest derivatives, most probably, Merkel cells. The ultrastructural findings confirm Toker's original concept that trabecular carcinomas comprise a distinct group of skin tumor. The recognition of these tumors would enable one to make such a diagnosis on frozen section, which, in turn, might provide an opportunity for more specific cytochemical and immunofluorescent characterization.

https://acsjournals.onlinelibrary.wiley.com/doi/epdf/10.1002/1097-0142%28197811%2942%3A5%3C2311%3A%3AAID-CNCR2820420531%3E3.0.CO%3B2-L

Trabecular carcinoma of the skin. An ultrastructural study

Congenital condylomata acuminata.

A distinctive, benign, spindle cell tumor of the breast is described. Three patients were men, the fourth a woman. Histologically, each tumor displayed islands of spindle or stellate cells embedded in a collagenous matrix. Within the female breast, the lesion was within the stroma, displacing but not including the epithelial elements. Ultrastructural study of two tumors revealed diverse populations composed of fibroblasts, myofibroblasts, smooth muscle cells, and undifferentiated mesenchymal cells. The relationship of these tumors to spindle cell lipomas is discussed. The lesions have all been clinically benign, and their recognition as such is important.

Benign spindle cell breast tumor

An unusual pulmonary tumor was identified on the basis of light and electron microscopic findings as glomangioma. The ultrastructural findings of intracytoplasmic fibrils with dense bodies, electron-dense plaques, pinocytotic vesicles, and basement membranes are consistent with smooth muscle origin. The differential diagnosis between our tumor and other unusual tumors is discussed. The occurrence of a glomangioma in the lung may indicate the existence of pulmonary glomera.

Glomangioma of the lung.

We present a solitary uterine tumor that occurred in a 28-year-old woman who complained of vaginal bleeding Grossly, the tumor was well circumscribed and composed of lobulated tissue that varied from yellow, tan and soft, to white and rubbery At the light microscopic level, areas identical to those described and interpreted as sex-cord differentiation in a group of closely similar uterine tumors were found and obtained for electron microscopic study Ultrastructurally, there were two basic types of cells, neither of which can be interpreted as sex-cord derivatives Cells that closely resembled the predominant components of Clement and Scully's group I tumors were similar to the normal endometrial stromal cells Cells that formed plexiform cords demonstrated features diagnostic of smooth muscle cells Cellular contents in cells comprising the tubular structures resembling that interpreted as indistinguishable from that of a Sertoli-cell tumor (tubular androblastoma) were probably smooth muscle cells We propose the term "Stromomyoma" to designate this peculiar uterine tumor The similarity between our tumor and those reported in the literature raises the possibility that "uterine tumor resembling" ovarian sex-cord tumors" are actually stromomyomas

Chik-Kwun Tang

Papers

Trabecular carcinoma of the skin. An ultrastructural study

Congenital condylomata acuminata.

Benign spindle cell breast tumor

Glomangioma of the lung.

Stromomyoma of the uterus