Basal cell carcinoma with tumor epithelial and stromal giant cells: a variant of pleomorphic basal cell carcinoma

Trichoblastic sarcoma: a high-grade stromal tumor arising in trichoblastoma

We report a case of primary sarcoma of the skin with a biphasic histological pattern, being composed of areas of mixed mesenchymal-epithelial cell proliferation and areas of purely sarcomatous growth. The tumor occurred in the posterior cervical region of a 93-year-old man, and its history was marked by sudden, rapid enlargement after many years of stable duration. The excised lesion was about 4 cm in diameter, had a firm consistency and was covered by intact skin. Histological examination showed a multifocal proliferation of follicular germinative cells arranged in corymbiform and petaloid shapes with an overall retiform growth pattern. Epithelial cords and strands were composed of cytologically uniform cells with bland nuclear features and were surrounded by a prominent, fibroblast-rich stroma reminiscent of a perifollicular sheath. In many areas of the tumor the stroma showed abrupt transition into a pleomorphic proliferation of large sarcomatous cells with frequent and often atypical mitoses. Multinucleated neoplastic cells infiltrated the epithelial structures to cause their partial or total obliteration in many fields of the lesion. Immunohistochemically, the epithelial cells displayed expression of various keratins, with a particularly intense staining for 34betaE12, and were partly positive for the CD10 antigen. A strong immunostaining for this antigen was also observed in malignant-appearing stromal areas, where no expression of cytokeratins was detected. Moreover, nuclear positivity for p53 protein was seen in sarcomatous cells, whereas it resulted in total lack of epithelial elements. Our case emphasizes that high-grade sarcoma may occur in the spectrum of trichoblastic tumors and that it may share some features of other noncutaneous biphasic neoplasms, such as mammary cystosarcoma phyllodes.

Pleomorphic Basal Cell Carcinoma: Case Reports and Review

Pleomorphic basal cell carcinoma is a pathologic variant of basal cell carcinoma characterized by the presence of atypical-appearing, mononuclear or multinucleated giant cells. Including our 3 patients, a total of 52 pleomorphic basal cell carcinomas have been described in 48 individuals. The tumors usually present as a nodule on the head or neck. The nuclei of the giant tumor cells are irregularly shaped, hyperchromatic, and 2 to 10 times larger than the nuclei of the surrounding cancer cells. Atypical mitoses may be present. The pathogenesis of pleomorphic basal cell carcinoma remains to be determined; however, investigations utilizing electron microscopy, immunohistochemistry, image analysis, and flow cytometry have provided additional insight regarding the features of the giant tumor cells and the etiology of this cancer. All of these tumors are aneuploid. Although these aneuploid tumors have alarming microscopic features, their clinical course is similar to that of basal cell carcinomas without pleomorphic giant tumor cells. Therefore, appropriate therapy to ensure adequate treatment of the tumor is recommended. Our patients' pleomorphic basal cell carcinomas were successfully treated by excision using the Mohs micrographic surgical technique.

Trichoepithelioma With Giant and Multinucleated Neoplastic Epithelial Cells

We report an unusual example of trichoepithelioma containing giant and multinucleated cells in the epithelial compartment. The patient was a 52-year-old woman who presented with a solitary nodule on the scalp measuring 2 cm of apparently long duration. The biopsy revealed a typical trichoepithelioma. The unusual feature was the presence in some epithelial nodules of large epithelial cells with hyperchromatic nuclei and no visible nucleoli that exceed 3 to 5 times the adjacent follicular germinative cells. Often, multinucleated cells were seen. Rare nodules were almost entirely composed of giant/multinucleated cells. The majority of the nodules containing giant cells were situated in the deeper portion of the neoplasm. No mitoses were seen in these giant cells. No enlarged or multinucleated cells were seen in the stroma. The neoplastic epithelial cells were diffusely reactive for bcl-2, including the giant and multinucleated cells. The proliferating rate was low; Ki-67 stained some giant cells. CD34 stained the stroma. We believe that the focal presence of pleomorphic giant cells in trichoepithelioma has no clinical or prognostic implications and does not denote its "malignant transformation".

Fibroepithelioma of pinkus with tumor giant cells

A case of fibroepithelioma of Pinkus with pleomorphic epithelial giant cells is reported. The lesion was an ovoid polypoid nodule measuring 4 mm x 3 mm x 2 mm and was located close to the right axilla in an 86-year-old woman. The immunohistochemical features of the epithelial giant cells indicate that most of these cells are not cycling. We suggest that these cellular changes may represent a senescent event. Giant cells showed a mean nuclear major diameter more than twice that of small cells. Flow cytometric study of the tumor showed a hypodiploid DNA content and an intermediate grade S-phase fraction of the aneuploid component. To the best of our knowledge, a pleomorphic variant of Pinkus fibroepithelioma has not been reported to date. In fibroepithelioma of Pinkus, the correct diagnosis depends primarily on the architectural pattern of the tumor rather than on its cytologic features.

Actin-binding protein fascin expression in skin neoplasia

BACKGROUND

Fascin containing actin bundles provide mechanical support to cellular protrusions and stress fibers. In cancers, some malignant cells (e.g. subsets of breast and ovarian carcinomas) express fascin. In skin cancer, the role of fascin is unknown.

METHODS

Cases of 61 keratocytic neoplasms, 35 melanocytic neoplasms, nine extramammary Paget's disease (four with adenocarcinoma) and five sarcomas (angiosarcoma and atypical fibroxanthoma) were examined by immunohistochemistry, using monoclonal antihuman fascin antibody, clone 55 k-2 (Dako Corporation, Carpinteria, CA, USA).

RESULTS

Fascin labeled all sarcomas and all keratinocytic neoplasms except for pagetoid pattern Bowen's disease. The regions of most intense fascin labeling were seen in the basal cells of infiltrative tumor margins. A minority of Merkel cell carcinomas exhibited weak or absent immunoreactivity. All melanocytic nevi except for some junctional nests of dysplastic melanocytic nevi expressed fascin. However, pagetoid cells of melanoma in situ and epithelioid cells of invasive melanoma weakly expressed or did not express fascin, whereas melanoma cells exhibiting spindle cell morphologies labeled intensely with fascin. Lastly, all cells of extramammary Paget's disease and most associated adenocarcinomas cells did not or were faintly labeled by fascin antibodies. Decreased or absent fascin expression was significantly associated with skin cancers with a high risk for metastasis (e.g. melanoma) vs. those with a low risk (e.g. basal cell carcinoma) (24% vs. 100% with > 50% immunoreactivity; p = 0.0001, chi-squared test).

CONCLUSION

Fascin is expressed by skin tumors that locally infiltrate and replace surrounding tissues indicating a role for fascin in cell adhesion, cell motility and invasiveness. No or weak fascin expression is exhibited by cancers with pagetoid intraepidermal spread and by invasive tumors with a high risk of metastasis. Downregulation or loss of fascin's actin-bundling properties, probably associated with disorganization of cell-cell and cell-matrix contacts, may be a crucial step in the progression from locally invasive to widely disseminating cancers.

Anaplastic neoplasms arising from basal cellcarcinoma xenotransplants into SCID-beige mice

BACKGROUND

An animal model for the study of basal cell carcinoma (BCC) is required to better understand its biology. Several attempts to grow BCC in immuno-incompetent animals have been only modestly successful.

METHODS

To test the ability of BCC to grow in a mouse with complete and severe immuno-incompetence, 14 individual BCC were transplanted into the subcutaneous tissue of 18 SCID-beige mice (T, B and natural killer cell deficient). Light microscopy and immunophenotypic analyses were performed on primary BCC and first and seventh passage tumors.

RESULTS

Transplantation of three BCC yielded rapidly growing anaplastic tumors for a tumor take of 18% (3/18). SCID-beige mice without tumor growth had mostly scars or epidermoid cysts at the transplant sites. The three patients whose BCC gave rise to the anaplastic tumors were significantly older than those without tumor growth (87 vs. 64, p = 0.001), but they did not differ with respect to BCC type or general health. These three anaplastic tumors were histologically and immunophenotypically similar, being composed of dyscohesive, pleomorphic cells that expressed vimentin and smooth muscle actin. In the first passage mice these tumors were locally invasive, tumor-forming nodules associated with an expansion of donor inflammatory cells (T and B lymphocytes and plasma cells), rare remnants of BCC epithelium and epidermoid cysts. By the seventh passage, the tumors were homogenous and metastasized widely throughout the mice. Changing transplantation location to the dermis to wound environment or supplementing the tumor with BCC-derived fibroblasts did not alter the phenotype or growth rate in SCID-beige mice. Anaplastic tumors also grew easily in SCID mice (T and B cell deficient). However, transplantation of the anaplastic tumors into normal mice (CB-17) or less severely immunodeficient mice (NCr and Balb/c: T and natural killer cell deficient) did not allow for growth. Furthermore, tumor growth could not be maintained in vitro.

CONCLUSION

Empirically, these data suggest that BCC has the potential to become an aggressive metastatic neoplasm, given the right immune and stromal environment. Moreover, a functional B lymphocyte system appears to prevent this growth. As human lymphocytes also engraft in SCID-beige mice, the original host immune response could be responsible for the lack of tumor growth in the majority of xenografts. Furthermore, the anaplastic and metastatic phenotype of these BCC derived neoplasms may be the experimental equivalent of metastatic BCC and BCC associated with carcinosarcoma.

The origin of transformed cells. studies of spontaneous and induced cell transformation in cell cultures from marsupials, a snail, and human amniocytes

Transformation of cells in culture is a model system for carcinogenesis, and two major theories (i.e., mutagenesis and aneuploidy) have emerged from in vitro and in vivo studies. A third view is presented here on the initial steps in the change of primary cells to extended life cells, and their change to immortalized cells. Both changes involve identical, microscopically visible cell abnormalities hitherto dismissed as cell degenerative characteristics. The major cell changes (i.e., giant cells, nuclear fragmentation to form multinucleated cells [MNC]) translated into genetic terms begin with the creation of polyploidy by DNA endoreduplication, followed by amitotic division of these giant cells to produce MNC. Individual nuclei, surrounded by a cell membrane, bud from the surface of the MNC, and represent the origin of the transformed cells. Induced budding by a protease treatment of MNC suggests that the extracellular matrix is an inhibitor of the budding process from human MNC. The production of the MNC is a genetic process determined by two abnormal events (i.e., overproduction of DNA and amitotic chromosomal segregation) during which there are possibilities for different genetic mechanisms to produce inherited variability within and between MNC. These concepts are discussed in regard to carcinogenesis, and by extension its possible prevention by use of the special cytopathic cell changes in carcinogen testing and in clinical screening programs.

Trichoepithelioma with "monster" stromal cells

Trichoepithelioma is a benign tumor of trichogenic origin which appears predominantly in childhood or in young adults. Different forms have been described according to clinical and histological features. The authors report a unique variant of trichoepithelioma arising on the limb of a 27-year-old man. The tumor was characterized by the mixture of an atypical fibroxanthomatous proliferation and basaloid epithelial strands of trichoepithelioma. Such histological features have not been previously reported. It raises the question of an additional variant of hair follicle tumor with a mixed epithelial and mesenchymal proliferation.