Chromophobe renal cell carcinoma (CHRCC) is known for morphologic variability. Besides classic morphology, several other patterns like pigmented adenomatoid, multicystic, even papillary were documented. 10 cases of CHRCC composed of small cell population in various percentages that were analysed using morphologic parameters, immunohistochemistry and next generation sequencing. Patients were 5 males and 5 females with 40-78 age range. Size of tumors ranged from 2.2 cm to 11 cm (mean 5.17 cm). Small cell component comprised 10-80% of total tumor volume, the rest was formed by cells with classic morphology. Immunohistochemical profile followed typical CHRCC immunophenotype with positivity for CD117, CK7 among others. Neuroendocrine markers were negative. Mutations of 13 genes were found: DCIER1, FGFR3, JAK3, SUFO, FAM46C, FANCG, MET, PLCG2, APC, POLE, EPICAM, MUTYH, AR. However, only mutation of PLCG2 is listed as pathogenic. Recognition of small cell variant of CHRCC is not problematic in tumors, where “classic” CHRCC component is present. In limited material, like core biopsy, recognising this pattern could be troublesome. Very problematic might be in limited material like core biopsy. From our limited data it seems, that small cell morphology has no influence on prognosis.

Tumors exhibiting histopathological findings similar to those of hemangioblastoma of the central nervous system (CNS-HB) rarely develop in the kidneys. Currently, renal hemangioblastoma (RHB) is considered analogous to CNS-HB; however, they differ in gross appearance, as well as immunohistochemical and molecular findings. In contrast, some renal cell carcinomas reportedly comprise distinct, clear cell renal cell carcinoma (CCRCC)- and hemangioblastoma (HB)-like areas. Initially, renal cell carcinomas with HB-like features (RCC-HBs) were considered a morphological variant of CCRCC owing to their diverse histological findings. However, the immunohistochemical and molecular findings of RCC-HBs suggest that RCC-HB is distinct from CCRCC. Additionally, one of the RCC-HBs had a focal leiomyomatous stroma and TSC2 variant, suggesting that RCC-HB and RCC with fibromyomatous stroma (RCC-FMS) might belong to the same disease entity. Therefore, we comprehensively reviewed the clinical, pathological, and molecular features of RHB, RCC-HB, and the related tumors and discussed the similarities, differences, and relationships between them. We believe that our review would serve as a foundation for further investigation on elucidating the relationship between CNS-HB, RHB, RCC-HB, and RCC-FMS.

Periarticular chondromas are common in the humerus and femur but rarely occur in the temporomandibular joint. We report a case of a chondroma in the anterior part of the ear. One year prior to his visit, a 53-year-old man became aware of swelling in the right cheek region which gradually increased in size. In the anterior part of the right ear, there was a palpable 25 mm tumor, elastic and hard, with poor mobility and without tenderness. A contrast-enhanced computed tomography CT showed a mass lesion with diffuse calcification or ossification in the upper pole of the parotid gland and areas of poor contrast within. A magnetic resonance imaging showed a low-signal mass lesion at the parotid gland with some high signals in both T1 and T2. Fine-needle aspiration cytology did not lead to diagnosis. Using a nerve monitoring system, the tumor was resected with normal tissue of the upper pole of the parotid gland in the same way as for a benign parotid tumor. Distinguishing between pleomorphic adenoma, including diffuse microcalcification of the parotid gland and cartilaginous tumors of the temporomandibular joint, may be sometimes difficult. In such cases, surgical resection may be a beneficial treatment option.

Introduction: Enfortumab vedotin is a standard therapy for advanced urothelial carcinoma, but its efficacy may be limited by acquired resistance and spatial heterogeneity of Nectin‐4 expression. Case Presentation: We report the case of a 76‐year‐old woman with cT3N2M0 left renal pelvic urothelial carcinoma that was treated with first‐line chemotherapy, followed by pembrolizumab, and subsequently enfortumab vedotin. After 16 cycles of enfortumab vedotin, lymph node metastases remained shrunk, but isolated progression of the primary tumor occurred. Salvage nephroureterectomy was therefore performed, and the patient has remained recurrence‐free for one year postoperatively. Immunohistochemistry showed a marked decline in Nectin‐4 expression in the resected tumor compared with at the time of the initial biopsy. Conclusion: This case highlights the potential role of surgery for localized progression during enfortumab vedotin therapy. Nectin‐4 reassessment may be considered selectively at decision‐changing junctures when results are likely to alter management.