Mesenchymal benign

Dibromoethane is a potent carcinogen in rats and mice, causing malignant and benign neoplasms of epithelial and mesenchymal origin in multiple organ systems when administered by inhalation, oral, or dermal routes. Cancer was also induced at initial point of contact with... 

Benign mesenchymal tumours include angiomyolipoma, lymphangioma, haemangioma, infantile haemangio-endothelioma, leiomyoma, etc. 

Alterations in the liver parenchyma as a result of foreign substances are characterized by several parenchymal, mesenchymal and vascular basic reactions as well as by benign or malignant neoplasia. It seems reasonable to classify the morphological findings in accordance with the acuteness and chronicity of their occurrence - bearing in mind all fundamental and individual reservations with regard to their systematization, (s. tab. 29.2). 

Differential diagnosis of circular hepatic foci helps to decide whether therapeutic measures are necessary, not required, or not feasible. The histological classification of benign coin-like hepatic lesions differentiates between (7.) hepatocellular tumours, (2.) cholangiocellular tumours, (i.) mesenchymal tumours, and (4.) tumour-like lesions. There may also be evidence of (J.) calcareous foci. (4, 7, 12, 15) (s. tab. 36.2)... 

Angiolipoma This benign mesenchymal tumour consists of fatty cells and numerous blood vessels, which have a tendency to thrombose. In general, angiolipomas occur singly in both liver lobes. 

Most neoplasms are classified and named based on (1) the cell or tissue of origin and (2) benign or malignant growth characteristics. There are two basic cell types from which neoplasms may originate mesenchymal cells and epithelial cells (Figure 2). Mesenchymal pertains to mesenchyma (embryonic... 

The liver is host to a wide variety of both benign and malignant primary tumors. It is also the second most common site of metastases metastatic tumors account for 90% to 95% of all hepatic malignancies. The primary tumors may arise from many cell lines in the liver but most commonly from parenchymal and biliary epithelial cells and mesenchymal cells (Table 47-10). The two most important primary liver tumors are HCC and cholangiocarcinoma. 

Subcutis Benign mesenchymal neoplasms—various types No Bruner et al. (2001), Evans et al. (1997), ICRT (1993b)... 

Miettinen M, Sarlomo-Rikala M, Sobin LH. Mesenchymal m-mors of muscularis mucosae of colon and rectum are benign leiomyomas that should be separated from gastrointestinal stromal mmors—a clinicopathologic and immunohistochemical study of eighty-eight cases. Mod Pathol. 2001 14 950-956. 

As in any other organ, immunostains can be of great utility in resolving a variety of spindle cell mesenchymal lesions occurring in the prostate including benign and malignant smooth muscle neoplasms, peripheral nerve sheath tumors, and rhabdomyosarcoma (Table... 

An inflammatory myofibroblastic tumor (IMT) of the bladder may arise either spontaneously or as a result of a prior instrumentation of the bladder. IMTs are benign mesenchymal neoplasms composed of a proliferation of relatively monotonous myofibroblastic cells (typical tissue culture appearance) in a richly vascularized background with red blood cell extravasation and lym-phoplasmacytic inflammatory infiltrate. Mitotic activity ranges from absent to brisk. Abnormal mitotic figures... 

This is a very rare, possibly benign uterine tumor that is characterized by a cytologically bland and largely mitot-ically inactive proliferation of spindle cells in a myxoid matrix. The main differential diagnostic considerations include myxoid leiomyoma and leiomyosarcoma and endometrial stromal neoplasm with myxoid stroma. All inflammatory myofibroblastic tumors reported in the largest series were ALK-positive, which is similar to what has been described to occur in other sites. " All uterine mesenchymal neoplasms studied were ALK-negative, including smooth muscle and endometrial stromal tumors and carcinosarcomas. 

Tumors derived from the sex cords or ovarian mesenchyme compose 5% to 12% of all ovarian neo-plasms. 413 Benign tumors in the fibroma-thecoma group are relatively common. Other sex cord-stromal tumors and mesenchymal tumors are rare. The most common malignant sex cord- stromal tumor is granulosa cell tumor, which composes 1% of 2% of all malignant ovarian tumors. There are two types of granulosa cell tumors an adult type that occurs mainly in postmenopausal... 

Oliva E, Young RH, Clement PB, et al. Cellular benign mesenchymal tumors of the uterus A comparative morphologic and immunohistochemical analysis of 33 highly cellular leiomyomas and six endometrial stromal nodules, two frequently confused tumors. Am J Surg Pathol. 1995 19 757-768. 

Wargotz ES, Weiss SW, Norris HJ. Myofibroblastoma of the breast. Sixteen cases of a distinctive benign mesenchymal tumor. Am J Surg Pathol. 1987 11 493-502. 

Mesenchymal hamartoma of the liver (MHL) is another benign neoplasm in children. Boys are slightly more affected than girls. It is very unusual to find an MHL after 5 years of age. The lesion usually has a good prognosis (Ramirez-Garredo et al. 2003 Yen et al. 2003). 

Benign mesenchymal lesions such as lipomas, fibromas and leiomyomas may also occur. 

Benign mesenchymal tumors are very rare and include lipoma, fibroma, and neurofibroma. They may be pedunculated and protrude from the vagina. 

Apart from hemangioma, other benign mesenchymal lesions of the liver are relatively rare and do not show pathological features that are of value for a sufficiently specific diagnosis at imaging techniques. Hence histology assessment (either on an adequate biopsy specimen or on the resected lesions) is usually unavoidable. Some mesenchymal lesions are more frequent in children. Specific aspects are described in the pertinent literature, mostly as single case reports due to the limited number of observed cases or, in a few instances, summarized in short reviews. 

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