Chromophobe renal cell carcinoma with sarcomatoid and heterologous osteosarcoma-like differentiation: a case report and literature review.

Chromophobe renal cell carcinoma (CRCC) is a subtype of renal cell carcinoma (RCC) with a favorable prognosis. Sarcomatoid differentiation in RCC is assumed to be the outcome of the parent tumor's dedifferentiation and associated with poorer prognosis. Sarcomatoid differentiation can be detected in CRCC as well as other subtypes, but the occurrence of divergent osteosarcoma-like components in sarcomatoid CRCC is extremely unusual. Only six cases have been previously reported in the literature, we reviewed them and presented the seventh case in a 71-year-old male who had a left kidney heterogeneous mass. The resected tumor showed a sarcoma-like spindle cell area with an adjacent osteosarcoma area producing lacy bone material and bony trabeculae in a hard area mixed with a typical CRCC. In conclusion, sarcomatoid CRCC with osteosarcomatous differentiation is a very rare tumor and should be kept in mind especially when dealing with small or frozen sections biopsies.

Metastatic Perivascular Epithelioid Cell Tumor Of The Kidney: A Case Report With Emphasis On Response To The Tyrosine-Kinase Inhibitor Sunitinib.

Several case reports have provided most of the information available on perivascular epithelioid cell tumors, but with no consensus regarding diagnosis or treatment paradigms. Sunitinb is a VEGFR multitargeted tyrosine-kinase inhibitor that is regarded as a first-line treatment of clear cell-type metastatic renal-cell carcinoma after cytoreductive surgery. Our case was a 29-year-old male who presented with a metastatic left renal tumor and underwent left partial nephrectomy followed by adjuvant tyrosine kinase-inhibitor treatment. We report this case to present the peculiarity of this rare pathological variant, its clinical and diagnostic features, and challenges regarding treatment options, since the response of this rare tumor to adjuvant tyrosine kinase-inhibitor therapy has not been well described.

Single Large Bladder Stone in a Young Male Adult with Primary Hyperparathyroidism.

Bladder stones are caused when minerals are built up in the bladder, especially if the bladder is incompletely emptied. These stones will pass while they are small. Otherwise, they get stuck to the bladder wall or ureter. If this happens, they gradually gather more mineral crystals, becoming larger over time. Primary hyperparathyroidism is usually caused by a tumor within the parathyroid gland, and elevated calcium levels can cause digestive symptoms, psychiatric abnormalities, bone disease and multiple kidney stones.

Upper Tract Urothelial Carcinoma in Ectopic Pelvic Kidney.

Upper tract urothelial carcinoma (UC) is an uncommon tumor. Ectopic kidney is also a rare entity. The combination of these two conditions is very rare. A 49-year-old male complained of right flank pain with hematuria. On CT scan he was found to have a malrotated right kidney with soft tissue seen in the upper calyceal group and a normal left kidney. Diagnostic cystoscopy was unremarkable. Radical nephroureterectomy with bladder cuff excision was performed. Pathology report revealed low grade urothelial carcinoma. Patient's symptoms disappeared postoperatively. Follow up showed no recurrence during the first two years in the bladder and upper tract in the contralateral kidney. Isolated UC of ectopic kidney is rare disease three cases were reported in literature. Although treatment of this tumor can be challenging due to its complex blood supply and position inside the pelvis, treatment strategy is still similar as for orthotopic kidneys.