Table 2 Reported cases of SOM in metastatic papillary urothelial carcinoma of the bladder
Case | Age-Sex | Tumor site, description ± related circumstances | Histological findings | IHC profile within the metaplastic component | Treatment | Grade | Outcome | Reference |
|---|---|---|---|---|---|---|---|---|
1 | 54y-M | Abdominal wall, midway between umbilicus and pubis symphisis: hard fibrous plaque of 2,2 × 1,6 × 1 cm with central bone formation, 4y. history of papillary urothelial bladder carcinoma with prostatic enlargement treated by transurethral bladder resections, cystodiathermy cauterizations and transvesical prostatectomy. | -Well differentiated papillary urothelial carcinoma surrounded by fibrous connective tissue, presumed as scar tissue; and muscle. -SOM characterized by well-formed bone. | WNP | Surgical resection. | 1 | NA | [11] |
2 | 65y-M | Left supraclavicular region: firm and partially fixed mass, measuring 1,5 × 1,5 cm, 2y. after radiotherapy and partial cystectomy for a papillary urothelial bladder carcinoma. | Left supraclavicular region: fibro-adipose tissue with prominent metaplastic bone formation and several foci of malignant cells consistent with metastatic papillary urothelial carcinoma. | WNP | Irradiation. | 3 | NA | [12] |
Left tibia: extensive lysis and sclerosis of the entire tibial shaft, 1y. after supraclavicular metastatic localization. | Left tibia: poorly differentiated papillary urothelial carcinoma invading bone, soft tissue and striated muscle with metaplastic bone formation. | |||||||
Left femur proximal end: third metastatic focus, 8 m. after tibial metastasis. | Left femur proximal end: similar histological pattern to supraclavicular and tibial metastases. | |||||||
3 | 54y-M | Left tibia: metastatic localization, 14 m. after primary tumor. | NA | NA | NA | NA | NA | [13] |
4 | 74y-F | Left tibia: metastatic localization with amorphous ossification in surrounding soft tissue, 14 m. after primary tumor. | Metastatic papillary urothelial carcinoma with new bone. | NA | NA | NA | NA | [13] |
5 | 64y-F | Right femur, right and left tibiae: metastatic tumor with ill-defined bone destruction and heterotopic soft tissue ossification, 24 m. after primary tumor. | NA | NA | NA | NA | NA | [13] |
6 | 78y-M | Massive nodal metastases on radical cysto-prostatectomy with lymph node dissection specimens for urothelial bladder tumor. | Metastatic papillary urothelial carcinoma with osseous metaplasia seen only in lymph nodes. | NA | Radical cystoprostatectomy with lymph node dissection. | 3 | NA | [14] |
7 | 75y-M | . Nodal metastases on radical cysto-prostatectomy with bilateral ilio-obturator lymph node dissection specimens for urothelial bladder tumor. -Right retroperitoneal space: heterotopic bone formation, 1y. after surgery. | -Nodal metastases: poorly differentiated papillary urothelial carcinoma with small foci of mature lamellar-bone trabeculae, outlined by non atypical osteocytes. -Right retroperitoneal space: Similar histological pattern to nodal metastases. | WNP | Adjuvant chemotherapy and radiotherapy. | 3 | -Alive with progressing lesions resistant to radiotherapy at the time of the report. -No further available follow-up. | [3] |