Ultrastructure of mesodermal mixed tumor of the uterus.

A case of mesodermal mixed tumor arising in the uterus of a 57-year-old woman is presented. The tumor was a mixture of adenocarcinoma with occasional squamous metaplasia, stromal sarcoma, myxosarcoma and chondrosarcoma. Light and electron microscopic examinations of the tumor revealed close transition between stromal sarcomatous component and each of other sarcomatous and carcinomatous component. The histogenesis of mixed mesodermal tumor was discussed and it was concluded that the tumor might be derived from endometrial stromal cell which possessed the pluripotency to differentiate toward various epithelial and mesenchymal tissues including the heterologous mesenchymal tissue.     

Extrauterine mesodermal (müllerian) adenosarcoma: a clinicopathologic analysis of five cases.

Five extrauterine examples (three pelvic and two ovarian) of a distinctive mesodermal (müllerian) mixed tumor previously described to occur in the uterus and designated müllerian adenosarcoma are reported. The tumors were diagnosed during the fifth to eight decades of life. They usually formed very large, partly cystic masses, which had occasionally spread to adjacent organs by the time of operation. On microscopic examination the tumors consisted of benign-appearing neoplastic glands lying in a sarcomatous stroma. The glands were lined by a variety of müllerian epithelial cell types, and the stromal element resembled endometrial stromal sarcoma. Three patients had malignant courses manifested by intrabdominal recurrence, distant metastases, or both. This tumor should be clearly distinguished from the more common forms of mesodermal (müllerian) mixed tumor in which the epithilial as well as the stromal component is malignant and the prognosis is much more grave.     

Concurrence of malignant and benign heterologous mixed tumors of the uterus

A large polypoid uterine mas was composed to two distinct and separate parts: a malignant mixed müllerian tumor (MMMT) and a benign mixed mesenchymal tumor (BMMT). It was considered a collision of two neoplasms rather than a malignant degeneration of the BMMT. Malignant transformation of benign mesenchymal uterine tumors is a controversial concept which is difficult to prove or disprove. Concerning the histogenesis of MMMT it appears, at least in some cases, that they originate not from a single multipotential mullerian cell, but rather from two, a stromal cell and an epithelial cell. It is suggested furthermore, that in certain instances presence of one neoplastic component, e.g., adenocarcinoma, can incite proliferation of the second, sarcomatous element of the MMMT.     

Mesodermal (Muller) mixed ovarian tumor

A case of mesodermal (Müller) mixed tumor of the ovary is described. The tumor consisted of the endometrial component with benign epithelial structures, stromal sarcoma, rhabdomyosarcoma, and elements of undifferentiated sarcoma. By its histological structure the tumor may be classified as one of the variants of mesodermal (Müller) mixed tumor of the heterologous adenosarcoma type.     

Mixed epithelial and stromal tumor of kidney with malignant transformation: report of two cases and review of literature

We present 2 cases of mixed epithelial and stromal tumor of the kidney with sarcomatous transformation. One patient was a 53-year-old woman who presented with macroscopic hematuria. The resected tumor involved the right renal parenchyma, measuring 13.0 x 8.0 x 4.0 cm, and extended to perirenal adipose tissue. The second patient was a 56-year-old woman who presented with right flank colic pain. The tumor measured 6.0 x 5.5 x 4.0 cm, with an intact capsule at the upper pole. Both tumors showed a well-circumscribed, multilocular, cystic, and focally solid mass. Sections of both tumors revealed benign and malignant components. The benign component consisted of multilocular cysts and fibrous stroma with a focally ovarian stromalike component. The malignant component in both cases was predominantly composed of undifferentiated cellular spindle cell sarcoma with frequent mitoses. One case showed additional heterologous malignant elements, including rhabdomyosarcomatous, chondrosarcomatous, and focal carcinomatous components. We report 2 additional cases of sarcomatous transformation in mixed epithelial and stromal tumor of the kidney.     

Primary malignant mixed mesodermal tumor of the gallbladder

Summary A rare case of primary malignant mixed mesodermal tumor of the gallbladder arising in a 75 year old woman is reported. The previously published cases of similar tumors were reviewed in order to outline the histological features and the histogenesis. In diagnosing a malignant mixed mesodermal tumor of the gallbladder it was imperative that we excluded malignant neoplasms with multiple histological patterns. The diffuse and close intermingling of the epithelial and mesenchymal component ruled out a collision tumor. The high mitotic rate, the typical reticulin pattern and the obviously malignant osteoblasts excluded a spindle cell carcinoma with osseous metaplasia. The authors conclude that this is the first case of malignant mixed mesodermal tumor with evident osteosarcomatous areas, described in the gallbladder.     

Role of Electron Microscopy in Metastatic Endometrial Stromal Tumors

Endometrial stromal tumors may pose a problem in diagnosis when they appear as metastatic lesions without a known primary tumor. To determine the usefulness of electron microscopy in identifying them in these situations, optimally fixed low-grade stromal sarcomas (five), normal endometrial specimens (six), and malignant mesodermal mixed tumors (four) were studied. The endometrial stromal sarcomas had a general resemblance to normal proliferative endometrial stroma, being composed of undifferentiated cells, fibroblasts, and myofibroblasts. One stromal tumor showed evidence of partial epithelial differentiation. One of the four malignant mesodermal mixed tumors had a fibrosarcomalike component, but there was insufficient resemblance to normal endometrial stroma to indicate a relationship between the two. Together with a review of the literature, this study indicates that electron microscopy is useful in the diagnosis of low-grade endometrial stromal tumors by demonstrating characteristic cellular findings as well as a lack of features specific for other round cell and spindle cell neoplasms.     

Malignant phyllodes tumor with chondrosarcomatous differentiation: report of a case with cytological presentation

Malignant phyllodes tumor is a rare breast tumor with neoplastic epithelial and stromal components. The stromal component may show homologous and heterologous sarcomatous elements, including chondrosarcomatous and osteosarcomatous differentiation. Because these tumors may present with an almost exclusively sarcomatous component, it is important for the pathologist to include this entity in the diagnostic considerations of fine-needle aspirations of breast neoplasms showing sarcomatous differentiation. Following surgical excision, careful examination of the gross specimen and thorough sampling of the specimen is recommended before rendering a definitive histologic diagnosis. We describe the cytologic and histologic findings in a case of malignant phyllodes tumor with sarcomatous overgrowth showing predominantly chondrosarcomatous differentiation.     

Extrauterine mesodermal (müllerian) adenosarcoma. A case report

Extrauterine mesodermal (müllerian) adenosarcomas have only recently been described, and this is the first reported case from Australia. These tumours fall within the category of common epithelial tumours' in the World Health Organisation (W.H.O.) classification of ovarian tumours and comprise benign looking epithelial structures (glands, papillae) in association with sarcomatous stroma. They are thus distinct from malignant mesodermal mixed tumours in which both epithelial and stromal elements are cytologically malignant.     

Histogenesis of metaplastic breast carcinoma and axillary nodal metastases

A 40-year-old breast-feeding woman presented with left breast swelling. On physical examination a 7 cm mass was found in the breast. Because biopsy demonstrated malignant tissue, mastectomy with axillary nodal dissection was performed. Pathological findings were consistent with metaplastic breast carcinoma with nodal metastases. The primary tumor consisted of three types of invasion: ductal, squamous, and sarcomatous. Furthermore, three morphological transitions were observed: ductal–squamous, ductal–sarcomatous, and squamous–sarcomatous. Ductal–squamous (12/18 microscopy slides) and squamous–sarcomatous transitions (10/18) were more commonly observed than ductal–sarcomatous transition (3/18). Furthermore, immunohistochemistry showed loss of epithelial marker (cytokeratin) and acquisition of mesenchymal markers (vimentin and α-smooth muscle actin) in the sarcomatous component. These findings suggested that epithelial–mesenchymal transition had occurred in the tumor and that two pathways, ductal–squamous–sarcomatous and ductal–sarcomatous transition, were involved in progression of metaplastic breast carcinoma. The main pathway appeared to be ductal–squamous–sarcomatous transition. Regarding the nodal metastases, of 13 positive nodes, ductal, squamous, and sarcomatous components were observed in 13, seven, and two nodes, respectively. Moreover, as in the primary tumor, ductal–squamous and squamous–sarcomatous transitions were observed. This suggested that the ductal component metastasized to the nodes and that epithelial–mesenchymal transition subsequently occurred within the nodes.     

A unique pancreatic ductal adenocarcinoma with carcinosarcomatous histology, immunohistochemical distribution of hCG-beta, and the elevation of serum alpha-feto-protein

Pancreatic undifferentiated carcinomas with a neoplastic mesenchymal component (carcinosarcoma) have not been well described to date. The author experienced an autopsy case of a unique pancreatic ductal adenocarcinoma with carcinosarcomatous histology. The patient was a 90 year old Japanese male who died of cahexia with generalized tumor extension. Post-mortem examinations revealed some distinctive or representative components discerned in the tumor tissue. One was the well differentiated ductal adenocarcinoma. The second and the major finding was undifferentiated short spindle shaped or small round sarcomatous cells, which lacked an epithelial nature but showed positivity for CD10+, CD56+, Ki67++, p53++, and were focally positive for Desmin and vimentin. These two components were mixed and constituted the histology of the carcinosarcoma. In another area, anaplastic, large, pleomorphic tumor cells showed the focal immunohistochemical distribution of alpha-feto-protein and human chorionic gonadotropin. An ultrastructural study revealed adenocarcinoma cells with apical mucin secreting granules and well developed ductal differentiation, whereas undifferentiated sarcomatous cells showed primitive fibroblastic or mesenchymal characters without specific differentiation. Conclusively these findings suggested that this well differentiated adenocarcinoma gradually enlarged, accumulated genetic alternations, and then transformed into large and undifferentiated tumor cells, rapidly growing small sarcomatous cells, and a histology of carcinosarcoma.     

Dedifferentiated mixed stromal-smooth muscle tumor of the uterus. Report of a case

So-called dedifferentiation in mesenchymal neoplasms of the uterus is very rare. Among conventional low-grade stromal tumors only three cases of dedifferentiation were reported, whereas in mixed stromal-smooth muscle tumors the dedifferentiation was yet not described. Here we present such a case of low-grade mixed stromal-smooth muscle tumor with dedifferentiation. The tumor occurred in 52-years-old postmenopausal patient. The high-grade component representing a dedifferentiation showed morphology of undifferentiated sarcoma with myxoid change. The low-grade component with morphology of mixed stromal-smooth muscle tumor was limited to a few peripheral areas of the lesion. Immunohistochemically, the low-grade component showed typical positivity for CD10, estrogen receptor, progesterone receptor, and focal reactivity for myoid markers, whereas the dedifferentiated component expressed only vimentin, CD10 and estrogen receptor. This case demonstrates that low-grade mixed stromal-smooth muscle tumor of the uterus can dedifferentiate like a pure stromal tumor. It shows that extensive sampling/histological search may be needed for recognition of a minor component in a dedifferentiated tumor.     

A case of small polypoid esophageal carcinoma with multidirectional differentiation, including neuroendocrine, squamous, ciliated glandular, and sarcomatous components

A small composite esophageal carcinoma measuring 1.5 x 1.4 x 1.0 cm is described. The tumor had a polypoid elevation with a superficial extension. Histologic examination revealed invasion of the submucosal layer and multidirectional differentiation, including neuroendocrine, squamous, ciliated glandular, and sarcomatous components. The neuroendocrine component was strongly positive for chromogranin and formed the bulk of the polypoid tumor. The squamous cell carcinoma exhibited a superficial extension. The adenocarcinoma was located in a small region of the tumor and contained ciliated glandular cells. The spindle cell sarcomatous component, which was positive for alpha-smooth muscle actin and negative for cytokeratin, exhibited no specific mesenchymal differentiation. Each component was found in 60%, 10%, 5%, and 25% of the tumor, respectively. Cases of small composite esophageal carcinoma containing various carcinomatous and sarcomatous components are extremely rare.     

Ovarian carcinoma recurring as carcinosarcoma

Malignant mixed mesodermal tumor is a rare tumor of the ovary and its histogenesis is controversial. We report the case of an ovarian tumor that seemed to be a pure carcinoma and recurred as a carcinosarcoma, and suggest a possible histogenesis for this kind of tumor. The patient was a 62-year-old Japanese woman. The primary tumor was confined to the right ovary and was a histologically poorly differentiated endometrioid adenocarcinoma with focal squamous differentiation. The tumor recurred as peritoneal dissemination 9 months later showing a histological appearance of carcinosarcoma of heterologous type. The recurrent tumor also contained intermingled foci of similar histology as the primary tumor. The carcinomatous component of the recurrent tumor showed more obvious differentiation to adenocarcinoma with increased expression of epithelial markers compared to the primary tumor. Epithelial membrane antigen was positive also in a few cells of the sarcomatous component, which implies that this tumor had features of metaplastic carcinoma. The DNA ploidy pattern of the primary ovarian tumor was diploid, while an additional aneuploid subpopulation appeared in the recurrent tumor. These findings suggest the possible histogenesis of carcinosarcoma of the ovary as progression and clonal evolution of endometrioid adenocarcinoma.     

Müllerian Adenosarcoma of the Uterus: Literature Review,Case Report,and Ultrastructural Observations

This is a report of a transmission and scanning electron microscopic examination of a müllerian adenosarcoma. The neoplasm had the characteristic pattern of benign neoplastic glands with focal squamous metaplasia and a sarcomatous stroma. Ultrastructurally, both mesenchymal and epithelial elements were identified. The mesenchymal components were Ultrastructurally identical to those present in endometrial stromal sarcomas, including active collagen synthesis. The epithelial component resembled benign endometrial glands, and there was significant secretory activity as evidenced by prominent cytoplasmic glycogen collections.     

Malignant islet cell tumor with sarcomatous differentiation.

Malignant mesenchymal neoplasms of the pancreas are rare and malignant islet cell tumors with sarcomatous dedifferentiation are rarer still. We present a case of malignant islet cell tumor with sarcomatous differentiation, which to our knowledge is only the second reported case showing such a combination of morphologic features. Clinically, the neoplasm was not hormonally active and immunohistochemical staining was negative for gastrin, glucagon, insulin and somatostatin. The sarcomatous component strongly reacted with an antibody directed against vimentin, and a minority of cells stained strongly with antisera directed against desmin and smooth muscle actin. The spindle cell component was nonreactive with antibodies directed against Factor VIII. The myogenous direction of differentiation in the present tumor is similar to that seen in the prior case report of malignant islet cell tumor with rhabdomyosarcomatous differentiation.     

Synchronous uterine carcinosarcoma and contralateral breast cancer after tamoxifen therapy: a case report

Uterine carcinosarcoma (malignant mixed Müllerian tumor, MMMT) is a rare aggressive malignant tumor, which demonstrates both malignant epithelial (carcinoma) and mesenchymal (sarcoma) components. Synchronous uterine carcinosarcoma and contralateral breast cancer in patient received tamoxifen treatment had not been reported. We present a case of uterine carcinosarcoma co-occurrenced with contralateral breast cancer in a 56-year-old nulliparous, obese breast cancer patient, who had been treated with tamoxifen for 5 years. The patient presented with palpable pelvic mass and vaginal bleeding. Histopathological evidence revealed that the tumor was comprised of an admixture of malignant epithelial and mesenchymal components. The epithelial component was endometrioid type adenocarcinoma, while sarcomatous component had heterologous elements including fusiform cell sarcoma and a prominent component of cartilage. The infiltrating ductal carcinoma has been diagnosed on her right breast. The patient died of disease 8 months after diagnosis. Postmenopausal patients, with adjuvant tamoxifen treatment for breast cancer, are at increased risk for the development of uterine carcinosarcoma and less benefit for contralateral breast cancer.     

Carcinosarcoma with rhabdoid features of the urinary bladder in a 2-year-old girl: possible histogenesis of stem cell origin

A case of carcinosarcoma of the urinary bladder in a 2-year-old girl is reported. The tumor, measuring 34 x 20 x 18 mm, was located in the peri-trigone area of the urinary bladder with polypoid features. Histologic examination revealed transitional cell carcinoma at the tumor surface with downward invasion. Concurrently, a sarcomatous area was found beneath the carcinoma, with these two different malignant components sharing on apparent transition without distinct boundaries. Sarcomatous components included immature round cells focally showing rhabdoid features. No rhabdomyomatous component was observed. Immunohistochemistry disclosed vimentin and cytokeratin-double positive cells at the transposition between carcinoma and sarcomatous components. In addition, ultrastructural analysis revealed that the epithelial cells had a distinct junctional complex, and the sarcomatous cells occasionally had a meshwork of cytoplasmic intermediate filaments, indicating bidirectional cytodifferentiation to epithelial and mesenchymal elements. The extremely young age at which this case of carcinosarcoma occurred suggests that the tumor may be of mesodermal stem cell origin.     

Malignant mesothelioma of the tunica vaginalis testis: a case with a predominant sarcomatous component

We present a case of malignant mesothelioma (MM) of the tunica vaginalis testis. A 64-year-old man was referred for an operation on a right hydrocele that later proved to be a tumor during surgery. The tumor was malignant with a biphasic pattern of epithelial and sarcomatous components. The latter component was predominant. Cuboidal or columnar cells formed irregular tubular structures in the epithelial component. In contrast, spindle-shaped or polygonal cells formed intricate structures with stromal connective tissues in the sarcomatous component. Immunohistochemical staining revealed that the tumor was mesothelial in origin and positive for cytokeratin, vimentin, HBME-1 antigen and calretinin. In general, MM occur in the pleura or peritoneum; those originating in the tunica vaginalis testis are very rare and represent less than 5% of all MM. In addition, MM in the tissues usually consist primarily of an epithelial component. According to previous reports tumors with a predominant sarcomatous component are extremely rare. In general, a sarcomatous component predicts poor prognosis and our case does, in fact, deteriorate over time. Our case suggests that despite its low incidence, MM must be considered when a case is diagnosed as hydrocele testicle.