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

Stromal osseous metaplasia in urothelial carcinoma of the bladder: An unusual and challenging feature. A case report

A 62-year-old male presented with pain and haematuria starting 3 months before. The computed tomography showed focal and mural bladder thickening with ureteropelvic dilatation. The following transurethral bladder resection revealed a high-grade muscle-invasive urothelial carcinoma. In the subsequent cystoprostatectomy we found the same tumour, but adding focal tumour-associated stromal osseous metaplasia. Ossifying metaplasia is an extremely rare feature in urothelial carcinoma, with a few reported cases and represents a diagnostic challenge, mimicking radiotherapy-induced sarcoma or sarcomatoid carcinoma.

Papillary urothelial neoplasm of low malignant potential with osseous metaplasia in a 19-year-old chronic smoker: A case report with review of literature

Urothelial tumors characteristically occur in elderly persons, more commonly in males with typical complaints of hematuria. Although few studies attempted to describe clinic-pathological features of urothelial malignancies in young patients, due to heterogeneity in the inclusion of age groups under "young patients" no reliable conclusions can be derived. Herein, we are describing an interesting case of papillary urothelial neoplasm of low malignant potential with osseous metaplasia in a 19-year-old chronic smoker young patient presented with chief complaints of abdominal pain with a review of the literature.

Peritoneal carcinomatosis with desmoplasia and osseous metaplasia mimicking encapsulating peritoneal sclerosis in a cat: case report

A 13-year-old neutered male Korean short-hair cat presented with anorexia, lethargy, and a severely distended abdomen, suggestive of ascites. Abdominocentesis yielded serosanguineous fluid. A subsequent diagnostic workup, including blood tests, ascitic fluid analysis, imaging studies [radiography, ultrasound, and computed tomography (CT)], and histopathological examination, was performed to identify the underlying cause. Imaging studies revealed characteristics of encapsulating peritoneal sclerosis (EPS) such as peritoneal thickening, fat stranding, and calcification. During laparotomy, fibrous membranes encapsulating the abdominal organs and ascites were observed, and multiple calcified regions were detected on the abdominal wall. Histopathological analysis confirmed the diagnosis of poorly differentiated invasive malignant neoplasms, which were further classified as carcinomatosis based on positive cytokeratin and negative vimentin immunohistochemistry results. To our knowledge, this is the first report of sclerosing peritoneal carcinomatosis with osseous metaplasia in a cat.

Juvenile polyps with osseous metaplasia treated by endoscopic mucosal resection

A 17-year-old male with no previous medical history presented with a 1-year history of rectal bleeding, mucus discharge and occasional rectal prolapse. Colonoscopy revealed several polypoidal growth masses in the distal rectum, formed by multiple sessile polyps with a glistening mucus-covered surface and fleshy, friable appearance, that coalesced forming large conglomerates. Given their complexity and large size, piecemeal endoscopic mucosal resection of the rectal lesions was performed and histopathological examination revealed ulcerated polypoid mucosa with mixed inflammatory cell infiltrate in the lamina propria and dilated cystic mucus-filled glands. Remarkably, bony trabeculae surrounded by osteoblastic cells were also seen. These findings were consistent with juvenile polyps with foci of osseous metaplasia. Osseous metaplasia has been described in a wide variety of tissue types, such as prostate, uterus, breasts, lungs and urinary tract, with respect to both neoplastic and non-neoplastic conditions. However, it is exceedingly rare in colonic polyps and, to the best of our knowledge, only 9 cases have been described in juvenile polyps.

Heterotopic ossification in primary rectal cancer with squamous cell carcinoma-like differentiation

OBJECTIVES

Heterotopic ossification (HO), which occurs when bone tissue forms outside the skeleton, is extremely rare in rectal cancer. Adenocarcinoma is the histological type of all reported primary colorectal cancers with HO. However, in the present case, we observed areas of adenocarcinoma with squamous cell carcinoma-like differentiation. Here we conducted histopathological and immunohistochemical analyses to identify the mechanisms of HO development, to differentiate between adenocarcinoma and squamous cell carcinoma-like phenotypes, and to understand the associated prognostic implications.

CASE REPORT

A 62-year-old woman was admitted to our hospital with symptoms of intermittent hematochezia without abdominal pain. Colonoscopy revealed stenosis with a protuberant mass in the rectum. Abdominopelvic contrast-enhanced computed tomography showed irregular wall thickness of the rectum, multiple lymph node metastases, and liver metastases. The rectal tumor exhibited calcified deposits with marked hyperintensity. We then performed Hartmann's operation and D3 lymph node resection. The biopsy specimen revealed tubular and solid adenocarcinoma nests and squamous carcinoma-like components over a necrotic extent without secreted mucin. She received chemotherapy (mFOLFOX6 with bevacizumab) as the first option and is alive 5 months after surgery.

CONCLUSION

To the best of our knowledge, this is the first case of heterotopic ossification in a primary rectal cancer with squamous cell carcinoma-like differentiation that was surgically resected. This case suggests that BMP-2 transformed fibroblasts and pluripotent stem cells into osteocytes. We conclude that the squamous cell carcinoma-like lesion was squamous metaplasia of adenocarcinoma.

In Situ Gene Expression in Native Cryofixed Bone Tissue

Bone is a very complex tissue that is constantly changing throughout the lifespan. The precise mechanism of bone regeneration remains poorly understood. Large bone defects can be caused by gunshot injury, trauma, accidents, congenital anomalies and tissue resection due to cancer. Therefore, understanding bone homeostasis and regeneration has considerable clinical and scientific importance in the development of bone therapy. Macrophages are well known innate immune cells secreting different combinations of cytokines and their role in bone regeneration during bone healing is essential. Here, we present a method to identify mRNA transcripts in cryosections of non-decalcified rat bone using in situ hybridization and hybridization chain reaction to explore gene expression in situ for better understanding the gene expression of the bone tissues.

Osseous Metaplasia in a Bladder Diverticulum in a Patient with Mosaic Menkes Disease

Menkes disease, or Kinky Hair Syndrome, is a rare disorder of copper metabolism that causes fatal neurodegenerative disease in infancy. This X-linked disorder results from mutations in the ATP7A gene. Along with neurological decline, characteristic coarse appearance of the hair is seen. Urological issues are prevalent in this patient population, with bladder diverticula being the most common. Herein, we describe a unique male patient with genetic mosaicism and osseous metaplasia found in a ruptured bladder diverticulum.