No abstract

Xp11.2 translocation carcinoma is a distinct subtype of renal cell carcinoma characterized by translocations involving the TFE3 gene. Our study included the morphological, immunohistochemical and clinicopathological examination of 28 Xp11.2 RCCs. The immunophenotype has been assessed by using CA9, CK7, CD10, AMACR, MelanA, HMB45, Cathepsin K and TFE3 immunostainings. The diagnosis was confirmed by TFE3 break-apart FISH in 25 cases. The ages of 13 male and 15 female patients, without underlying renal disease or having undergone chemotherapy ranged from 8 to 72. The mean size of the tumors was 78.5 mm. Forty-three percent of patients were diagnosed in the pT3/pT4 stage with distant metastasis in 6 cases. Histological appearance was branching-papillary composed of clear cells with voluminous cytoplasm in 13 and variable in 15 cases, including one tumor with anaplastic carcinoma and another with rhabdoid morphology. Three tumors were labeled with CA9, while CK7 was negative in all cases. Diffuse CD10 reaction was observed in 17 tumors and diffuse AMACR positivity was described in 14 tumors. The expression of melanocytic markers and Cathepsin K were seen only in 7 and 6 cases, respectively. TFE3 immunohistochemistry displayed a positive reaction in 26/28 samples. TFE3 rearrangement was detected in all the analyzed cases (25/ 25), including one with the loss of the entire labeled break-point region. The follow-up time ranged from 2 to 300 months, with 7 cancer-related deaths. In summary, Xp11.2 carcinoma is an uncommon form of renal cell carcinoma with a variable histomorphology and rather aggressive clinical course.

The morphotype and grade of renal cell carcinoma (RCC) in 928 nephrectomies were reclassified according to the 2016 WHO classification in order to analyze the distribution and outcomes of RCC subtypes in Hungary, to assess whether microscopic tumor necrosis is an independent prognostic factor in clear cell RCC, and to study whether a two-tiered grading (low/high) for clear cell and papillary RCC provides similar prognostic information to that of the four-tiered ISUP grading system. 83.4% of the cohort were clear cell, 6.9% papillary, 4.5% chromophobe, 2.3% unclassified, 1.1% Xp11 translocation, 1.1% clear cell papillary, 0.3% collecting duct and 0.1% mucinous tubular and spindle cell RCCs. RCC occurred in 16 patients with end-stage kidney disease and none of them displayed features of acquired cystic kidney disease-associated RCC. The 5-year survival rates were as follows: chromophobe 100%, clear cell papillary 100%, clear cell low-grade 96%, papillary type 1 92%, clear cell high-grade 63%, papillary type 2 65%, unclassified 46%, Xp11 translocation 20%, and collecting duct 0%. The 5-year survival rates in low-grade and high-grade papillary RCC were 95% and 59%, respectively. In clear cell RCC, only the grade, the stage and the positive surgical margin proved to be independent prognostic factors statistically. Overall, papillary RCC occurred relatively infrequently; microscopic tumor necrosis in clear cell RCC did not predict the outcome independently of the tumor grading; and the assignment of clear cell and papillary RCCs into low-grade or high-grade tumors was in terms of survival no worse than the ISUP grading.

Due to the rarity and poor prognosis of these tumors, proper pathological diagnosis and early therapy are important. Therapeutic guidelines are not available. Surgery, radiotherapy and/or chemotherapy are possible treatment options; somatostatin analogs are used as standard therapy in case of well-differentiated neuroendocrine tumors.

Inflammatory myofibroblastic tumor (IMT) is a spindle cell neoplasm with low malignant potential, which may appear in different parts of the body. Uterine localization is rare, especially among children. Etiology is unclear, although some authors suggest underlying trauma or distress. A 3.5-year-old girl was treated at our institute for recurring vaginal bleeding without injury or known pathology. Physical examination and laboratory analysis revealed no specific findings, contrast-enhanced MRI found a 25 × 28 × 30 mm-sized inhomogeneous soft tissue mass in the uterus wall, which was excised in toto. Histological examination identified a spindle cell pattern, and the FISH test revealed ALK gene rearrangement, the lesion was defined as an IMT. Six cases were published to date, and their diagnostic methods are not equivocal, CT, and PET CT were preferred instead of MRI. Aggressive therapy seems to be exaggerated according to low recurrence and metastasis occurrence, and crizotinib is proved as good therapeutic agent in those cases. Biopsy and histology has important role in order to distinguish IMT from malignancies completed with FISH examination because ALK positivity strengthens the diagnosis. No lethal outcome was published among children, as our patient is also symptom-free after 3 years.