Osteoclast-like giant cell carcinoma of the urinary bladder

Osteoclast-rich undifferentiated carcinoma of the bladder and the diagnostic usefulness of immunohistochemistry. A case report

Osteoclast-rich undifferentiated carcinoma (ORUC) of the urinary tract is a rare variant of urothelial carcinoma, first described in 1985 by Kitazawa et al. It has a worse prognosis compared to other histological variants of invasive urothelial carcinoma and its diagnosis may prove challenging due to the variability in its immunohistochemical profile. We present a case of ORUC in which GATA3 immunostaining was a useful diagnostic tool.

The optimal management of variant histology in muscle invasive bladder cancer

Bladder cancer is a heterogenous disease that is associated with tangible mortality in muscle invasive disease. The WHO 2016 classification of urothelial tumours reflects the contemporary approach towards histological variants in bladder cancer, including variants of urothelial carcinoma (UC) and non-urothelial variants. This review focuses on variant histology in UC, and discusses the importance of accurate histological diagnosis, and subsequent risk stratification and therapeutic decision making based on proper variant recognition. Most urothelial variants are associated with poorer outcomes compared to conventional UC, although some perform reasonably better. However, high quality evidence detailing optimal treatment and survival outcomes are still lacking in literature, due to the rarity of these cases.

An expanded immunohistochemical profile of osteoclast-rich undifferentiated carcinoma of the urinary tract

Osteoclast-rich undifferentiated carcinoma of the urinary tract (ORUCUT) is a rare tumor composed of ovoid to spindle-shaped mononuclear cells with intermixed or focally clustered osteoclast-like giant cells. Previous studies have demonstrated that the mononuclear cells are neoplastic cells, while the giant cells are reactive cells of histiocytic lineage. The association between these tumors and classic urothelial carcinomas suggest that the mononuclear cells are derived from urothelial cells; however, no studies have been conducted to assess the immunohistochemical profile of ORUCUT with more specific urothelial markers. This study identified 21 cases of ORUCUT and performed immunohistochemistry for GATA3, uroplakin II, and thrombomodulin along with pancytokeratin (AE1/3) on all cases. Mononuclear cells stained positive in 20 cases (95%) for GATA3 and 19 cases (90%) for thrombomodulin. None of the mononuclear cells were positive for uroplakin II and only three cases showed focal positivity for AE1/3. The osteoclast-like giant cells were negative for GATA3, uroplakin II, thrombomodulin, and AE1/3, providing additional support to a reactive origin for these cells. Additionally, 15 cases (71%) were associated with either in situ or invasive urothelial carcinoma. This study provides an expanded immunohistochemical profile for ORUCUT and more definitively supports a urothelial origin for this tumor.

Primary osteoclast-like giant cell tumor of parotid gland: A rare extraskeletal presentation with diagnostic challenges

Primary osteoclast-like giant cell tumor (OC-GCT) has been rarely described in extraskeletal sites. The diagnosis primarily hinges on the detection of giant cells. However, these giant cells are also seen in many giant cell lesions, thus creating diagnostic confusion and dilemma. Here, we describe a rare case of a 24-year-old male with primary extraskeletal, OC-GCT presenting as a swelling in the right parotid region and highlight its cytological, histological and immunohistochemical characteristics with diagnostic challenges.

Osteoclast-like giant cell carcinoma of the distal ureter

Extraskeletal osteoclast-like giant cell (OGC) tumors are uncommon and have mainly been found in the breast and pancreas. OGC neoplasms of the urinary tract are extremely rare. Most cases found in the renal pelvis and bladder are associated with either an in situ urothelial malignancy or a conventional high-grade urothelial carcinoma. These malignancies tend to be associated with a poor prognosis and disease course. To our knowledge, no cases of OGC tumors of the distal ureter only have been published. Here, we present the case of a 76-year-old man who underwent hand-assisted laparoscopic nephroureterectomy because of painless gross hematuria with right flank pain. Pathologic examination showed OGC carcinoma of the right distal ureter. No local tumor recurrence or distant metastasis was found at the 5-month follow-up.

Fine needle aspiration biopsy of an osteoclast-rich undifferentiated urothelial carcinoma: A cytology case report and review of the literature

Osteoclast-rich undifferentiated carcinoma of urinary bladder (ORUCUB) is a very rare and an unusual variant of high-grade urothelial carcinoma. Here, we report an extraordinary case of metastatic ORUCUB, diagnosed by fine needle aspiration (FNA) biopsy, in a 74-year-old Hispanic male who presented with a palpable, tender left groin mass and a known previous history of high-grade carcinoma of urinary bladder and prostatic cancer. To the best of our knowledge, diagnosis of ORUCUB by FNA is the first case report in FNA cytology to be published to date. A review of the literature is emphasized on the cytological, histological and immunohistochemical features and differential diagnoses of giant cell tumor.