A 68-year-old Japanese man was admitted to our hospital because of sudden hematuria and abdominal pain. Endoscopic and imaging techniques including CT, MRI, and PET revealed a bladder tumor. Transurethral biopsy and clinical cytology revealed malignant tumor composed of giant cells, and cystectomy was performed. Macroscopically, the bladder contained a large polypoid and ulcerated reddish tan tumor (5 × 6 cm).
For histological evaluation, 17 tissue specimens were obtained from the tumor. Histologically, the tumor consisted of the following three elements: giant cell sarcomatoid carcinoma (70% in area), squamous cell carcinoma (20% in area), and papillary urothelial transitional cell carcinoma (10% in area) (Figure 1). The giant cell sarcomatous element and squamous cell carcinoma element were invasive into the peribladder fat tissue, while the transitional cell carcinoma element was invasive into the submucosa.
The sarcomatoid element was composed of malignant polygonal and spindle giant cells with frequent multinucleated giant cells (Figure 2). The giant cells had hyperchromatic nuclei and showed many mitotic figures. The giant cell sarcomatoid carcinoma area was homologous, and did not show heterologous elements such as bones and cartilages. Specific structures including herring bone and storiform appearances were not recognized. The tumor cells did not show plasmacytoid features. Lymphocytic infiltration was absent.
The squamous cell carcinoma element was composed of malignant squamous cell with individual keratinization and intercellular bridge formation. Many mitotic figures were recognized in the squamous cell carcinoma element. There were gradual merges between the giant cell sarcomatoid and squamous cell carcinoma elements (Figure 3). There were occasional lymphovascular permeations by the giant cell sarcomatoid carcinoma and squamous cell carcinoma elements.
The papillary urothelial transitional cell carcinoma was grade II carcinoma with a few lymphovascular permeations. No transitions were observed between the transitional cell carcinoma element and the other two elements.
An immunohistochemical study was performed with the use of Dako Envision method, as previously reported [10, 11]. The reagents and results are shown in Table 1. The giant cell sarcomatoid carcinoma element was positive for various kinds of cytokeratins, epithelial membrane antigen, and vimentin. It was negative for other mesenchymal markers such as desmin and S100 protein. P53 protein was positive and Ki-67 labeling was 72%. It was negative for CD68. The squamous cell carcinoma element was strongly positive for various types of cytokeratins and epithelial membrane, but was negative for vimentin and other mesenchymal markers. Neuroendocrine antigens and melanoma antigens were absent. P53 was positive, and Ki-67 labeling was 72%. The papillary urothelial transitional cell carcinoma element showed the similar results to those of the squamous cell carcinoma element, but the former was positive for cytokeratin 20 (Table 1). Both the epithelial elements were positive for p53 and showed high Ki67 labeling (squamous cell carcinoma, 67%; transitional cell carcinoma, 32%). Other antigens examined were negative (Table 1).
A diagnosis of bladder carcinoma composed of three different elements was made. The patient was treated by palliative chemotherapy and radiation, but died of systemic metastases 32 months after the operation. Autopsy was not performed.