Mesenchymal tumour

A group of 40 weanling outbred female Wistar rats received a single subcutaneous injection of 200 mg/kg bw 1,2-dimethylhydrazine. Four rats died within four days after the injection. Twenty-five of 36 rats that survived for more than four days and were killed within one year after 1,2-dimethylhydrazine administration developed renal tumours, nine of them bilateral. Pulmonary metastases were foimd in one animal. Twenty-five (73%) of 34 tumours examined histologically were diagnosed as nephroblastoma-like tumours similar to human Wilms tumour, three were mesenchymal tumours, three were adenomas, two were adenocarcinomas and one was unclassifiable (Sadrudin et al., 1985). 

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

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. 

Epithelioid haemangioendothelioma is a malignant mesenchymal tumour, which was first described in the liver by s.w. Weiss et al. in 1982. (s. tab. 37.1) It is probably a variant of haemangiosarcoma, but with a much better prognosis (approx. 50% of patients survive for more than 5 years). This multifocular, vascularized tumour with low-grade malignancy can affect the liver... 

Rhabdomyosarcoma is a mesenchymal tumour of grey colour with partially cystic growth. (12) It mainly occurs during childhood. (277) The tumour cells appear small, round or spindle-like, hyperchromatic, occasionally with eosinophilic cytoplasm. (279) They show various stages of differentiation of embryonal skeletal muscle cells. This tumour originates from peribiliary located muscu-... 

Fibrosarcoma is a mesenchymal tumour originating from fibroblasts it can therefore occur ubiquitously in the whole body. (12) It was first described by R.H. Jaefe in 1924. About 35 cases have been reported so far. This type of tumour has a firm consistency and contains cystic structures with focal necroses and haemorrhages. It possesses a fibrous pseudocapsule and consists of fascicu-larly arranged, spindle-like or fusiform tumour cells embedded in parallel collagen fibres. The non-epithelial stroma marker vimentin is overexpressed. These cells may exhibit marked polymorphism. Fibrosarcoma mainly occurs in men of advanced age. Therapy consists of tumour resection and adjuvant chemotherapy. (280,281)... 

Primary hepatic osteosarcoma is a very rare mesenchymal tumour, which was first described by J.H. Maynard et al. in 1969. It is of greyish-white to pale yellow colour and shows a gritty consistency. It grows rapidly with an aggressive behaviour. The survival time is short. Histologically, there are different components, such as osteoblastic, chondroblastic and fibroblastic cells. Numerous osteoblastic-like giant cells are present. Expression of vimentin is positive, whereas actin, des-min and cytokeratin are not detectable. The tumour cells produce lace-like osteoid. (291, 292)... 

Ireton HJC, McGiven AR, Davies DJ. 1972. Renal mesenchymal tumour induced in rats by dimethylnitrosamine light- and electron-microscope studies. Path 108 181. 

Ishak KG, Anthony PP, Niederau C, Nakanuma Y. Mesenchymal tumours of the liver. In Hamilton SR, Aaltonen LA, eds. Tumours of the Digestive System. Lyon, France International Agency for Research on Cancer (lARC) 2000 191-198. 

Penile cancer is a rare tumour in Europe with an incidence of 1 per 100,000 men per year (Busby and Pettaway 2005). As illustrated in Chapter 13, it is most commonly diagnosed in the 6th and 7th decades of life, but can occur at any age, including childhood. Squamous cell carcinoma is by far the most common malignant disease of the penis, accounting for more than 95% of cases. Malignant melanomas and basal cell carcinomas are less common. Mesenchymal tumours such as Kaposi s sarcoma, angiosarcoma, and epithelioid haemangioendothelioma are very uncommon, with an incidence rate of less than 3%. 

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