Stromal osseous metaplasia in carcinoma of the bladder

Stromal osseous metaplasia in urothelial carcinoma of the bladder: a rare case report and literature review

BACKGROUND

The bone formation within bladder tumors could be encountered in 3 conditions. These might consist of malignant bone formation in mesenchymal tumors; mixed mesenchymal and epithelial tumors; and epithelial tumors with stromal osseous metaplasia (SOM). This last is relatively rare. According to the English literature, only 12 cases have been reported in primary tumor and 7 in metastatic deposits of bladder primaries. Herein, we presented an additional case.

CASE PRESENTATION

An 83-year-old man was admitted 13 years ago for prostatic adenocarcinoma, treated with radical prostatectomy. Biochemical recurrence was detected 2 years after surgery (prostate-specific-antigen (PSA) level: 4.60 ng/mL) and progressively normalized (<1.0 ng/mL) after adjuvant radiotherapy and annual injection of leuprorelin (enantoneR). He was referred after 8 years for hematuria, PSA level having slightly increased (0.60 ng/ml). Cystoscopy showed a nodular growth in the bladder wall, visualized as a calcified tumor on computed tomography (CT) and removed with transurethral resection. Histologically, the tumor consists of a non-muscle-invasive high grade papillary urothelial carcinoma with metaplastic bone within the stroma. Immunohistochemical analysis particularly demonstrated positive expression of respectively CD56 on osteoblasts, and CD68 on osteoclasts. MDM2 and CDK4 were negatives on osteoid and bone tissue. Six courses of Bacillus Calmette-Guerin (BCG) therapy have been administered. Two local recidives have occurred during an 8-month follow-up period after immunotherapy and were treated with six further courses of BCG therapy. At one-month follow-up, the patient was well without remaining symptoms.

CONCLUSION

SOM is a rare benign condition whose pathogenesis remains uncompletely defined. Sarcomatoïd carcinoma represents the main differential diagnosis that influences therapeutic procedures. Prognosis depends essentially on the extent of the carcinomatous component .

Ossifying metaplasia of urothelial metastases: original case with review of the literature

Background

Ossifying metaplasia is an unusual feature of urothelial carcinoma, with only a few cases reported. The largest series included 17 cases and was published in 1991. The mechanism of ossification is unknown and hypotheses of osteogenic precursor cells, inducing bone formation, are proposed.

Case presentation

A 75 year-old patient was treated for a high grade transitional cell carcinoma of the bladder by surgery, chemotherapy and radiotherapy. Histology showed foci of bone metaplasia, both at the periphery of the tumor, and in a lymph node metastasis. 1 year later, a heterotopic bone formation was discovered in the right retroperitoneal space, near the lumbar spine, increasing rapidly in size during follow-up. Several imaging exams were performed (2 CT, 1 MRI, 1 Pet-CT), but in the absence of typical features of sarcoma, diagnosis remained unclear.

Histology of a CT-guided percutaneous biopsy showed urothelial carcinoma and mature lamellar bone. Integration of these findings with the radiological description of extraosseous localization was consistent with a diagnosis of osseous metaplasia of an urothelial carcinoma metastasis. The absence of bone atypia in both the primary and metastases argues against sarcomatoid urothelial carcinoma with osteosarcomatous differentiation.

Conclusion

Osseous metaplasia of an urothelial carcinoma metastasis is unusual, and difficult to distinguish from radiotherapy induced sarcoma, or from sarcomatoid carcinoma. Rapid progression, sheathing of adjacent structures such as vessels (like inferior vena cava in our case) and nerves and bony feature of lymph node metastases necessitate histological confirmation and rapid treatment. Our case illustrates this disease and evaluates the imaging features. In addition we discuss the differential diagnosis of osseous retroperitoneal masses.

Osseous metaplasia of the eyelid: report of 2 cases

This article describes 2 unusual cases of osseous metaplasia occurring within the eyelid and presents a brief review of the literature on cutaneous calcification. A 62-year-old man sought treatment for an eyelid mass containing osseous metaplasia in an area of lymphoid hyperplasia. An extensive oncologic workup ruled out malignancy. A 46-year-old man with a history of recurrent chalazion sought treatment for a firm mass of the upper eyelid that demonstrated bone formation in an area of sebaceous glands. Both lesions were excised with no further recurrence. Osseous metaplasia of the eyelid is a rare entity with diverse etiologies ranging from congenital syndromes to trauma, neoplasm, and inflammation. In some cases, a precise etiology cannot be identified.

Incidentally discovered osseous metaplasia within high-grade urothelial carcinoma of the bladder

A 66-year-old male presented with gross hematuria and acute renal failure secondary to bilateral ureteral obstruction. Further work-up revealed muscle invasive urothelial carcinoma. Pathologic examination following radical cystoprostatectomy revealed high grade urothelial carcinoma with focal tumor-associated stromal osseous metaplasia. Reactive bone formation within urothelial carcinoma is a very rare clinical entity. Although typically benign, the presence of mature bone elements warrants thorough examination for sarcomatoid components.

[Bladder carcinoma with osteoclast-type giant cells. A case with a rare presentation. Review of the literature]

We report a case of neoplasm of the urinary bladder with pseudosarcomatous stromal differentiation. Heterologous carcinosarcomas are extremely rare malignant neoplasms (seventy-eight cases have been previously described). This is a case of carcinoma containing numerous osteoclast type giant cells that stained for vinmentin and acid phosphatase and were negative for cytokeratin and lysozyme.

Primary osteosarcoma of the urinary bladder

Primary osteosarcoma of the bladder, together with transitional cell carcinoma, occurred in a 74-year-old female presenting with haematuria and lumbago. She was treated with chemotherapy and radical cystectomy. Though it was conceived to be curative, she died of a recurrence 5 months after the operation. Primary osteosarcoma of the bladder is an unusual and highly malignant disease. In spite of radical therapy, the outcome has been dismal with some exceptions.

Human urinary bladder-carcinoma cells are non-osteoinductive

Small pieces (ca. 2-3 x 3-5 mm) of the urinary-tract mucosa from noninvasive papillary transitional-cell carcinomas of the bladder (ca. urotheliale papillare, n = 33), invasive transitional-cell carcinomas of the bladder (ca. urotheliale papillare infiltrans, n = 6, papillary transitional-cell carcinomas of the bladder with squamous metaplasia (ca. urotheliale papillare cum metaplasia planoepitheliale, n = 4), transitional-cell carcinomas in situ (ca. urotheliale in situ, n = 2), and squamous-cell carcinomas of the bladder (ca. planoepitheliale, n = 2) were grafted intramuscularly into cortisone-immunosuppressed mice to test the ability of transformed transitional epithelium to induce heterotopic osteogenesis. Altogether, 156 implants from 47 cases of urinary bladder carcinoma were performed. Histological examination of implants, excised 10-17 days later, revealed relatively good survival of the grafted epithelium, which had proliferated and, in some cases, formed cysts and islands but failed to induce heterotopic osteogenesis in the surrounding host tissues. In nine implants prepared from four cases (noninvasive papillary transitional-cell carcinoma of the bladder and invasive papillary transitional-cell carcinoma of the bladder, two cases each) a small amount of cartilage and/or bone was found in the stroma of grafted tissue. The rarity of this phenomenon--together with the observation that implants of normal human urinary-tract mucosa have never induced the formation of cartilage/bone, whereas in a similar system, dog or guinea-pig grafts are osteogenic--suggests that the cartilage/bone present in the stroma of implanted cancers is the result of metaplasia of the stroma of the neoplasm and not the product of any osteoinductive potency of human urothelium.

Unusual forms of carcinoma of the urinary bladder

Carcinomas of the urinary bladder, which differ histologically from the usual transitional cell carcinoma of the bladder, are reviewed. These tumors, which account for approximately 15% of all bladder carcinomas, have diverse microscopic appearances. They fall into four major categories: variant forms of urothelial (transitional cell) carcinoma, squamous cell carcinoma, adenocarcinoma, and undifferentiated carcinoma. In the first category, the most common are carcinomas with glandular or squamous differentiation. Less common, but more troublesome diagnostically, are variants in which the cells are spindle shaped (sarcomatoid carcinoma), form small cysts (microcystic carcinoma), or differentiate toward trophoblast. In other variants, the stroma has unusual features that may lead to diagnostic difficulty. These are carcinomas with pseudosarcomatous stroma, osseous or cartilaginous metaplasia, or osteoclast-type giant cells. Also reviewed are squamous cell carcinoma and its variant, verrucous carcinoma. Vesical adenocarcinoma has several variants, including signet-ring cell and clear cell types. Finally, the category of undifferentiated carcinoma, including small cell carcinoma, giant cell carcinoma, and lymphoepithelioma-like carcinoma, is discussed.