Pleomorphic cells

Anaplastic Large-Cell Lymphoma (ALCL). These tumors are composed of CD30-positive pleomorphic cells. There are several variants common (accounting for about 70% of cases), lymphohistiocytic (10%), small cell (< 10%), and giant cell (rare) (B11, F5, K10, S23). 

Immunohistochemically, the fusiform and pleomorphic cells of STCs express vimentin. Labeling for keratin and EMA is also seen, but it may be quite focal (Fig. 11.34). This finding opens the door to the possibility that a small biopsy specimen could fail to demonstrate any epithelial markers because of sampling artifact. 

FIGURE 12.23 This clear cell tumor of lung is composed of significantly more pleomorphic cells than those shown in Figure 12.22. X400. 

Osteosarcoma Anaplastic, pleomorphic cells with morphologic spectrum, osteoid, bone formation. Heterogeneous, without a specific immunophenotype. Nonspecific numeric and structural abnormalities. 

Microscopically, OS is composed of anaplastic pleomorphic cells with a morphologic spectrum including spindle, round, ovoid, epithelioid, plasmacytoid, clear, and multinucleated cells. Usually more than one cell type is present in individual OS. Osteoid is required for the diagnosis. Variable bone formation, cartilage, and fibrous tissue may also be encountered. Histologic subtypes of conventional OS include osteoblastic, chondroblastic, and fibroblastic patterns. Ultrastructural studies have also demonstrated multiple cell types including osteoblastic, osteoclastic, chondroblastic, and fibroblastic features. ... 

Pleomorphic xanthoastrocytoma Pleomorphic cells are often vacuolated GFAP (S) type IV collagen (S) Leptomeninges cerebral cortex... 

A simpler polymer-extraction process using the highly fragile pleomorphic cells of A. vinelandii UWD formed after supplementing the nutrient broth with fish peptone [195] can be envisaged to also contribute to lower production costs. 

NOTE Axons that arise from cells in the DR nucleus are extremely fine with minute pleomorphic... 

Kazmierczak, B., B. Thode, S. Bartnitzke, J. Bullerdiek, and W. Schloot. 1992. Pleomorphic adenoma cells vary in their susceptibility to SV40 transformation depending on the initial karyotype. Genes Chromosomes Cancer 5(1) 35-9. 

Histology The parenchyma is formed from pluricellular trabeculae and two (or three) layers of hepatocytes, the width of which varies from location to location. The hepatocytes are rich in glycogen, often pleomorphic and enlarged, and usually show fine-drop)-let fatty deposits. No evidence of acinar architecture or Kupffer cells is found only very few preexisting and incorporated portal fields, central veins or bile ducts are detectable. There are numerous arteries and ectatic sinusoids the latter contain no Kupffer... 

The first liposarcoma observed in the liver was reported by J.I. Kim et al. in 1987. (289) Up to now, about 10 cases have been published. Bright yellow tissue containing mature fat cells admixed with scattered immature lipoblasts were found in various stages of development. Moreover, hyperchromatic nuclei in pleomorphic tumour cells, eosinophilic cytoplasm and fusiform cells were evident. (290) On US, liposarcoma is generally inhomogeneous with hypoechoic or hyperechoic features. Also on CT, this myxoid tumour is inhomogeneous and has Hounsfield units ranging from near-water density to that of muscle and may exhibit contrast enhancement. In addition, cystic areas and septated areas may be seen in MRI. 

In another study, the pathological lesions found in liver biopsies from patients treated with methotrexate were non-specific, consisting usually of macrovesicular steatosis, nuclear pleomorphism, chronic inflammatory infiltrates in the portal tracts, focal liver cell necrosis, fibrosis, and cirrhosis (52). 

Microscopic features Cells and structures formed by cells resemble normal tissues may be encapsulated Anaplastic, dysplastic, and pleomorphic may be associated with hemorrhage, necrosis, and inflammation... 

The waste products are partially deposited on the Bruch s membrane (Young, 1987) in the form of drusen. The accumulation of lipofuscin in RPE cells appears detrimental to its function (Flood et al., 1984) and causes photoreceptor death (Dorey et ak, 1989). With age, the number of RPE cells decreases in the central retina, and they become pleomorphic (Dorey et ak, 1989). Other changes are also frequent. They include atrophy, depigmentation, hyperplasia, hypertrophy, and cell migration. The melanin concentration in the RPE cells decreases with age, especially in Caucasians, but also in blacks (Feeney-Burns et al., 1984). The melanin granules are slowly (over decades) digested by lysosomes (Bums and Feeney-Burns 1980). 

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