High-resolution and highly accelerated MRI T2 mapping as a tool to characterise renal tumour subtypes and grades.

BACKGROUND: Clinical imaging tools to probe aggressiveness of renal masses are lacking, and T2-weighted imaging as an integral part of magnetic resonance imaging protocol only provides qualitative information. We developed high-resolution and accelerated T2 mapping methods based on echo merging and using k-t undersampling and reduced flip angles (TEMPURA) and tested their potential to quantify differences between renal tumour subtypes and grades. METHODS: Twenty-four patients with treatment-naïve renal tumours were imaged: seven renal oncocytomas (RO); one eosinophilic/oncocytic renal cell carcinoma; two chromophobe RCCs (chRCC); three papillary RCCs (pRCC); and twelve clear cell RCCs (ccRCC). Median, kurtosis, and skewness of T2 were quantified in tumours and in the normal-adjacent kidney cortex and were compared across renal tumour subtypes and between ccRCC grades. RESULTS: High-resolution TEMPURA depicted the tumour structure at improved resolution compared to conventional T2-weighted imaging. The lowest median T2 values were present in pRCC (high-resolution, 51 ms; accelerated, 45 ms), which was significantly lower than RO (high-resolution; accelerated, p = 0.012) and ccRCC (high-resolution, p = 0.019; accelerated, p = 0.008). ROs showed the lowest kurtosis (high-resolution, 3.4; accelerated, 4.0), suggestive of low intratumoural heterogeneity. Lower T2 values were observed in higher compared to lower grade ccRCCs (grades 2, 3 and 4 on high-resolution, 209 ms, 151 ms, and 106 ms; on accelerated, 172 ms, 160 ms, and 102 ms, respectively), with accelerated TEMPURA showing statistical significance in comparison (p = 0.037). CONCLUSIONS: Both high-resolution and accelerated TEMPURA showed marked potential to quantify differences across renal tumour subtypes and between ccRCC grades. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03741426 . Registered on 13 November 2018. RELEVANCE STATEMENT: The newly developed T2 mapping methods have improved resolution, shorter acquisition times, and promising quantifiable readouts to characterise incidental renal masses.

An atypical presentation of renal mass associated with BAP-1 tumor predisposition syndrome: Case report and review of literature.

BCRA-associated protein-1 (BAP-1) mutation has been associated with the development of a familiar syndrome that predisposes to tumors with a higher incidence than in general population, including melanoma and renal carcinoma. We report a 47-year-old woman diagnosed with a BAPoma (melanocytic tumor characterized by the loss of BAP-1). Due to her extensive family history with multiple neoplasms, a FDG PET-CT was performed. Consequently, she was diagnosed with an atypical renal mass, which is rarely linked to this syndrome. We review and discuss the available literature on the screening, diagnosis and treatment of renal tumors associated with BAP-1 tumor predisposition syndrome.

Renomedullary Interstitial Cell Tumor in the Background of a Renal Oncocytoma: A Case Report.

Renomedullary interstitial cell tumors (RMICTs) are rare benign renal tumors that arise from the renal medulla. They are rarely symptomatic and are mostly discovered incidentally. Radiologically, their co-presence ipsilaterally in the background of a larger mass introduces a miscellaneous presentation that raises the suspicion of metastatic disease. A characteristic presentation does not exist. Therefore, an individualized, patient-centered approach should be tailored depending on the nature of the presentation. We report the clinical, radiological, and histopathological presentation of a 46-year-old woman presenting with an RMICT in the background of a renal oncocytoma.

A Possible Association of Salivary Gland Tumors and Oral Lesions with Birt-Hogg-Dube Syndrome: A Systematic Review.

BACKGROUND: Birt-Hogg-Dube syndrome (BHDS) is an autosomal dominant syndrome with different skin, lung, and renal manifestations. It is diagnosed commonly in the third decade of life, and patients have an increased risk for pneumothorax and renal carcinomas. METHODS: Articles published in PubMed, and Medline from 1977 to September 2023, were included in the systematic review. Inclusion criteria were applied to case reports, case series, and a retrospective cohort study, describing clinical, histopathological, and genetic findings in patients with BHDS with oral and/or parotid lesions. RESULTS: Sixteen families/individuals with BHDS were identified for analysis. Patients ranged in age from 20 to 74 years, with an average of 49.4 years. Males were affected 52.2% of the time and females, 39.1%. Skin fibrofolliculomas were reported in 87% of cases, and oral lesions were documented in 47.8%. Parotid tumors were documented in 43.5% of patients, 30.4% of which were oncocytomas, 4.3% bilateral oncocytomas, and 4.3% "oncocytic carcinoma". CONCLUSIONS: Because BHDS is uncommon, its spectrum of clinical manifestations may be underrecognized, especially as the disease is mostly reported at advanced stage. And some of the patients with BHDS may have oncocytic parotid tumors and oral lesions. In this regard, patients presenting these lesions and other indications of BHDS should be considered for renal screening.

Comparison of conventional diffusion-weighted imaging and intravoxel incoherent motion in differentiating between chromophobe renal cell carcinoma and renal oncocytoma: a preliminary study.

OBJECTIVE: Quantitative comparison of the diagnostic efficacy of conventional diffusion-weighted imaging (DWI) and intravoxel incoherent motion (IVIM) in differentiating between chromophobe renal cell carcinoma (ChRCC) from renal oncocytoma (RO). METHODS: A total of 48 patients with renal tumours who had undergone DWI and IVIM were divided into two groups-ChRCC (n = 28) and RO (n = 20) groups, and the apparent diffusion coefficient (ADC), true diffusivity (D), pseudo-diffusion coefficient (D*), perfusion fraction (f) and their diagnostic efficacy were compared between the two groups. RESULTS: The D* values were higher in the ChRCCs group compared to the RO groups (0.019 ± 0.003 mm2/s vs 0.008 ± 0.002 mm2/s, P < .05). Moreover, the ADC, D and f values were higher in ROs compared to ChRCCs (0.61 ± 0.08 × 10-3 mm2/s vs 0.51 ± 0.06 × 10-3 mm2/s, 1.02 ± 0.15 × 10-3 mm2/s vs 0.86 ± 0.07 × 10-3 mm2/s, 0.41 ± 0.05 vs 0.28 ± 0.02, P < .05). The areas of the ADC, D, D* and f values under the ROC curves in differentiating ChRCCs from ROs were 0.713, 0.839, 0.856 and 0.906, respectively. The cut-off values of ADC, D, D* and f were 0.54, 0.91, 0.013 and 0.31, respectively. The AUC, sensitivity, specificity and accuracy of the f values were 0.906, 89.3%, 80.0% and 89.6%, respectively. For pairwise comparisons of ROC curves and diagnostic efficacy, IVIM parameters, that is, D, D* and f offered better diagnostic accuracy than ADC in differentiating ChRCCs from ROs (P = .013, .016, and .008) with f having the highest diagnostic accuracy. CONCLUSION: IVIM parameters presented better performance than ADC in differentiating ChRCCs from ROs. ADVANCES IN KNOWLEDGE: (1) D* values of ChRCCs were higher, while ADC, D and f values were lower than those of RO tumours. (2) f values had the highest diagnostic efficacy in differentiating ChRCC from RO. (3) IVIM parameters, that is, D, D* and f offered better diagnostic accuracy than ADC in differentiating ChRCC from RO (P=.013, .016, and .008).

Oncocytoma in adrenal gland.

Not required for Clinical Vignettes.

Acute Onset of Delayed Facial Nerve Paralysis After an Uncomplicated Total Parotidectomy for an Oncocytoma.

Facial nerve injury is one of the most substantial potential sequelae of parotid surgery. Pulling, stretching, and otherwise disturbing the facial nerve during parotid surgery can lead to post-surgical neural paresis and consequential deficits in facial movement. Furthermore, transection of the main facial nerve trunk or its branches, either purposeful or incidental, can lead to complete paralysis of the related facial musculature. Facial nerve injury is often diagnosed immediately post-operatively as evident by deficits in ipsilateral facial motion on examination of the patient in the recovery unit or, at most, by one week post-operatively. Although delayed onset facial nerve paralysis is seen in traumatic injury and otologic surgery, it is uncommon that facial nerve paralysis presents late after parotid surgery in the absence of hematoma development, viral reactivation, or secondary insult. Here, we present the case of a 70-year-old man developing a delayed acute onset of hemi-facial paralysis 12 days after right-sided total parotidectomy for an oncocytoma; a facial nerve examination done immediately post-operatively and at the one-week post-operative follow-up was found to be normal. The patient was treated with two courses of high-dose oral steroids with close-to-complete resolution.

Treatment modalities and outcomes of granular cell tumors and spindle cell oncocytomas of the pituitary gland: an analysis of two national cancer databases.

BACKGROUND: Spindle cell oncocytomas (SCO) and granular cell tumors (GCT) are rare primary pituitary neoplasms; the optimal treatment paradigms for these lesions are unknown and largely unexplored. Thus, using national registries, we analyze the epidemiology, management patterns, and surgical outcomes of SCOs and GCTs. METHODS: The National Cancer Database (NCDB; years 2003-2017) and the Surveillance, Epidemiology, and End Results Program (SEER; years 2004-2018) were queried for patients with pituitary SCOs or GCTs. Incidence, extent of surgical resection, and rate of postoperative radiation use for subtotally resected lesions comprised the primary outcomes of interest. All-cause mortality was also analyzed via time-to-event Kaplan-Meier curves. RESULTS: SCOs and GCTs have an annual incidence of 0.017 and 0.023 per 1,000,000, respectively. They comprise 0.1% of the benign pituitary tumors registered in NCDB. A total of 112,241 benign pituitary tumors were identified in NCDB during the study period, of which 83 (0.07%) were SCOs and 59 (0.05%) were GCTs. Median age at diagnosis was 55 years, 44% were females, and median maximal tumor diameter at presentation was 2.1 cm. Gross total resection was achieved in 54% patients. Ten patients (7%) had postoperative radiation. Comparing patients with GCTs versus SCOs, the former were more likely to be younger at diagnosis (48.0 vs. 59.0, respectively; p < 0.01) and female (59% vs. 34%, p = 0.01). GCTs and SCOs did not differ in terms of size at diagnoses (median maximal diameter: 1.9 cm vs. 2.2 cm, respectively; p = 0.59) or gross total resection rates (62% vs. 49%, p = 0.32). After matching SCOs and GCTs with pituitary adenomas on age, sex, and tumor size, the former were less likely to undergo gross total resection (53% vs. 72%; p = 0.03). Patients with SCOs and GCTs had a shorter overall survival when compared to patients with pituitary adenomas (p < 0.01) and a higher rate of thirty-day mortality (3.1% vs 0.0%; p = 0.013). CONCLUSION: SCOs and GCTs are rare pituitary tumors, and their management entails particular challenges. Gross total resection is often not possible, and adjuvant radiation might be employed following subtotal resection.

The Efficiency of Acoustic Radiation Force Impulse (ARFI) Elastography in the Differentiation of Renal Cell Carcinoma and Oncocytoma.

PURPOSE: This study is to investigate the effectiveness of Acoustic Radiation Force Impulse (ARFI) elastography in differentiating radiologically similar renal cell carcinoma (RCC) and oncocytoma in solid masses of the kidney. METHODS: The patients with solid renal mass histopathological diagnosed after excision or tru-cat biopsy who underwent a preoperative ARFI elastography of the lesion during a 4-year period were included in this study. Preoperative shear wave velocity (SWV) values were measured in all the lesions. SWV results of RCCs and oncocytomas were compared by an independent t-test, and cut-off, sensitivity and specificity values were calculated. RESULTS: Forty-two of the 60 patients included in the study were men (70%) and, 18 were women (30%), and the mean age was 59.7 ± 14 (27-94) years. Among 46 RCCs (76.6%), 23 and 14 oncocytomas, 5 (23.4%) were located in the right kidney (p:0.34722). Mean SWV values were found to be significantly higher in RCCs (2.87± 0.74 (0.96-4.14) m/s) than oncocytomas (1.83 ± 0.78 (0.80-3.76) m/s) (p <0.001). In the ROC analysis, a cutoff value of 2.29 m/s was found to havean 80.4% sensitivity and a 78.6% specificity for the discrimination of RCCs from oncocytomas. CONCLUSION: ARFI elastography measurements may be useful in distinguishing RCC and oncocytomas that may have similar solid radiological imaging features.

Renal cell oncocytoma tumor evolutions: a case report.

This report delineates the clinical progression of a renal oncocytoma in a 38-year-old female, initially asymptomatic, over a three-year follow-up period following her treatment for papillary thyroid cancer. The timeline of this case is as follows: In 2016, the patient was treated with total thyroidectomy and I131 for thyroid cancer. During an annual follow-up, an incidental renal mass was detected via FDG PET/CT, initially characterized as a benign, non-FDG-avid renal oncocytoma. Over two years, this lesion demonstrated a remarkable increase in FDG uptake and a slight growth in size, coupled with new I131 uptake in subsequent scans. These findings led to a reassessment of the diagnosis, initially suggesting a potential small renal cell carcinoma (RCC). Histopathological analysis eventually confirmed the diagnosis of oncocytoma. This case is notable for the tumor's unusual metabolic evolution and the challenges it posed in differential diagnosis.

Case of clear-cell oncocytoma of parotid gland and literature review.

Oncocytoma is a benign tumor of the salivary gland. Its incidence is very low and very seldom documen-ted in literature. Clear-cell dominant oncocytoma is even less common. The tumor's clinical symptoms and imaging results are nonspecific, so distinguishing other salivary gland tumors (such as oncocytic carcinoma) from clear-cell renal carcinoma is difficult, possibly leading to misdiagnosis and maltreatment. Here, a case of clear-cell dominant oncocytoma was presented, and the relevant literature was evaluated to investigate the diagnosis and management of clear-cell dominant oncocytoma.

Cushing's syndrome caused by adrenocortical oncocytoma: A case report.

Adrenal cortical eosinophilic adenoma usually presents as non-functional adrenal tumor but may lead to Cushing's syndrome in patients. The present article reports a patient with Cushing's syndrome caused by right adrenocortical oncocytoma. The patient was treated in Urology Department of Wuchuan People's Hospital (Zunyi, China) in November 2022 because of hirsutism, weight gain and hypertension. A laparoscopic right adrenal tumor resection was performed using an abdominal approach. Following surgery, blood pressure and heart rate of the patient fluctuated within a healthy range and menstruation returned to normal. Laparoscopic adrenalectomy has obvious advantages over open adrenalectomy, such as less trauma, shorter recovery time and fewer complications. Thus, this treatment for this rare disease is safe and feasible.

Low-grade oncocytic tumor: a review of radiologic and clinical features.

PURPOSE: The 2022 World Health Organization classification of renal neoplasia expanded the spectrum of oncocytic neoplasms to encompass newly established and emerging entities; one of the latter is the low-grade oncocytic tumor (LOT). This study reports the radiologic appearance and clinical behavior of LOT. METHODS: In this IRB-approved, HIPPA-compliant retrospective study, our institution's pathology database was searched for low-grade oncocytic tumors or neoplasms. Patient age, gender, and comorbidities were obtained from a review of electronic medical records, and imaging characteristics of the tumors were assessed through an imaging platform. RESULTS: The pathology database search yielded 14 tumors in 14 patients. Four patients were excluded, as radiologic images were not available in three, and one did not fulfill diagnostic criteria after pathology re-review. The resulting cohort consisted of 10 tumors (median diameter 2.3 cm, range 0.7-5.1) in 10 patients (median age 68 years, range 53-91, six women). All tumors presented as a solitary, well-circumscribed, mass with solid components. All enhanced as much or almost as much as adjacent renal parenchyma; all but one enhanced heterogeneously. None had lymphadenopathy, venous invasion, or metastatic disease at presentation or at clinical follow-up (median, 22.2 months, range 3.4-71.6). Among five tumors undergoing active surveillance, mean increase in size was 0.4 cm/year at imaging follow-up (median 16.7 months, range 8.9-25.4). CONCLUSION: LOT, a recently described pathologic entity in the kidney, can be considered in the differential diagnosis of an avidly and typically heterogeneously enhancing solid renal mass in an adult patient.

Low grade oncocytic renal tumor (LOT): Clinicopathological characterization of 13 cases.

CONTEXT: Low grade oncocytic tumor (LOT) is a recently recognized renal oncocytic neoplasm with unique morphologic and immunohistochemical pattern (CK7 +, CD117 -) that differentiates them from oncocytoma and chromophobe renal cell carcinoma (ChrRCC). OBJECTIVE: To further evaluate the histomorphological characteristics as well as the clinical outcome of low grade oncocytic tumors, retrospectively. DESIGN: Thirteen cases of LOT were identified from 463 cases of renal oncocytic neoplasm in our pathology archive. All tumors were immunostained with CK7, CD117 and other relevant markers. The pathohistological features and follow up data of these cases were recorded. RESULTS: Median age of patients was 76 years old (range from 36 to 86), with male to female ratio of 2:11. None of the patients had a syndromic association/hereditary condition. Eleven tumors were unifocal in each affected kidney, and two were multifocal with 2 and 3 separated tumors, respectively. On microscopic examination, tumors show variety of growth patterns, namely solid, compact nested, focal tubular/tubuloreticular and trabecular patterns. The stroma can be hypocellular and edematous where the tumor cells are loosely arranged exhibiting cords and scattered single cell arrangement. Immunohistochemically, all thirteen cases displayed strong and diffuse CK7 positivity in tumor cells. Eleven cases were CD117 negative and the other two showed focal and weak CD117 positivity (< 5% of tumor cells). Uniform tumor cell positivity was found for AE1/3, EMA, PAX8, and e-cadherin. Negative staining results include CAIX, AMACR, CD10 and vimentin. All cases in our cohort demonstrate indolent behavior and show no evidence of disease recurrence, progression, or metastases during the follow-up period up to 96 months. CONCLUSION: LOT is an emerging new entity of renal oncocytic neoplasm and demonstrates indolent clinical behavior. Its unique morphologic features and immunohistochemical patterns (CK7 +, CD117 -) set them apart from oncocytoma and ChrRCC.

Scars Run Deep: Problematic Morphology and Immunoprofile of Scars in Renal Oncocytomas.

In some instances, the central scar of renal oncocytoma can demonstrate entrapped cells with unusual morphology and aberrant immunoprofile creating potential diagnostic confusion. Herein, 100 renal oncocytomas containing scars with embedded epithelial cells were identified from 6 institutions, including nephrectomies (64% partial, 36% radical) of similar laterality (left = 51%) and sex distribution (male = 56%), with patient ages ranging from 38 to 86 years (mean = 64.3years) and tumor sizes ranging from 2 to 16 cm (mean = 5.3 cm). Immunohistochemistry was performed on all tumors for KRT7, KIT, vimentin, and CA9 with staining intensity and extensity separately analyzed. Of 4 architectural patterns of cells within the scar, 60% showed tubular pattern. Of 4 cytologies within the scar, flat/elongated (49%) and cuboidal cells (40%) predominated. Within the scar, 62% showed eosinophilic cytoplasm, with 38% showing both cleared and eosinophilic cytoplasm; notably, 79% showed higher grade nuclei than typical oncocytes. A subset of scar cells showed mucinous-like basophilic secretions (19%). Compared to background renal oncocytoma, tumor cells within the scar were more often positive for vimentin, KRT7, and CA9 and more frequently negativity for KIT. Specifically, of the notable "aberrant" immunoprofiles, 79% showed KRT7 positivity/KIT negativity/vimentin positive, 84% showed vimentin positivity/CA9 positivity, and 78% showed KIT negativity/vimentin positivity/CA9 positivity. While encountering scars within renal oncocytomas is not uncommon, what is not well appreciated is the unique morphology and immunohistochemistry of tumor cells within the scar. Comparing tumor morphology and immunoprofile of the scar to the background oncocytoma is helpful to avoid interpretative confusion.

Radiomics analysis based on single phase and different phase combinations of radiomics features from tri-phasic CT to distinguish renal oncocytoma from chromophobe renal cell carcinoma.

OBJECTIVES: To investigate different radiomics models based on single phase and the different phase combinations of radiomics features from 3D tri-phasic CT to distinguish RO from chRCC. METHODS: A total of 96 patients (30 RO and 66 chRCC) were enrolled in this study. Radiomics features were extracted from unenhanced phase (UP), corticomedullary phase (CMP), and nephrographic phase (NP) CT images. Feature selection was based on the least absolute shrinkage and selection operator regression (LASSO) method. The selected features were used to develop different radiomics models using logistic regression (LR) analysis, including model 1 (UP), model 2(CMP), model 3(NP), model 4(UP+CMP), model 5(UP+NP), model 6(CMP+NP), and model 7(UP+CMP+NP). The radiomics model demonstrating the highest discrimination performance was utilized to construct the combined model (model 8) with clinical factors. A nomogram based on the model 8 was established. To evaluate the diagnostic performance of the different models, the receiver operating characteristic (ROC) curve and decision curve analysis (DCA) were used. Delong's test was utilized to assess the statistical significance of the AUC improvement across the models. RESULTS: Among the seven radiomics models, model 7 exhibited the highest AUC of 0.84 (95% CI 0.69, 0.99), and model 7 demonstrated a significantly superior AUC compared to the other radiomics models (all P < 0.05). The AUC values of radiomics models based on two phases (model4, mode5, mode6) were greater than the models based on single phase (model1, mode2, mode3) (all P < 0.05). Model 3 illustrated the best performance of the three radiomics models based on single phase with an AUC of 0.76 (95% CI 0.57, 099). Model 6 illustrated the best performance of the three radiomics models based on two-phases combination with an AUC of 0.83 (0.66, 0.99). Model 8 achieved an AUC of 0.93 (95% CI 0.83, 1.00) which is higher than those all radiomics models. CONCLUSION: Radiomics models based on combination of radiomics features from UP, CMP, and NP can be a useful and promising technique to differentiate RO from chRCC. Moreover, the model combining clinical factors and radiomics features showed better classification performance to distinguish them.

Renal oncocytoma in a 13-year-old girl: A case report and literature review.

Renal oncocytoma is a benign renal neoplasm which has mostly been reported in adults. Occurrence in children is infrequent. To date, there are only six pediatric cases of renal oncocytoma reported previously. Herein, we report a 13-year-old girl presented with hematuria for a week. Abdominal computed tomography showed a well-defined heterogeneous solid mass with a stellate central scar in the left kidney. The patient underwent a nephron sparing surgery. Histopathological and immunohistochemical findings confirmed the diagnosis of renal oncocytoma. Though uncommon, renal oncocytoma should be considered as the differential diagnosis of renal tumor in children. In addition, intranuclear inclusions were firstly described in this pediatric patient with unclear significance, which need a large cohort to summarize and analyze.

Prognosis of Adrenal Oncocytic Neoplasms (AONs): Literature Review of 287 Cases and Presentation of the Oldest Patient.

INTRODUCTION: The adrenocortical oncocytic neoplasms (AONs) are rare tumors of the adrenal gland, classified as oncocytoma (AO), oncocytic neoplasm of uncertain malignant potential (AONUMP) and oncocytic carcinoma (AOC). The aim of this study was to perform a review of the literature, in order to evaluate the prognosis of these rare cancers. We also reported the oldest patient with AON. METHODS: A comprehensive literature review using as key words "adrenal oncocytoma", "adrenal oncocytic neoplasm", and "adrenal oncocytic carcinoma" was performed. REPORT OF THE CASE: We report the case of an 88-year-old woman receiving a left open adrenalectomy for an AON (15 × 10 × 8 cm). The considerable size and weight together with the presence of necrosis were indicative for a lesion with an uncertain potential for malignancy, according to Weiss modified criteria. After two years, the patient was free from any sign of recurrence. RESULTS: Only 287 AONs were detected in the scientific literature, exploring OVID, MEDLINE, PubMed and SCOPUS as dataset. These tumors are usually incidentalomas with an unpredictable malignant potential. Surgical resection remains the mainstay of treatment for AON. CONCLUSION: AO and AONUMP have an excellent prognosis and a low mortality rate, with only three cases of recurrence reported in the literature and one metastatic case four years after first adrenal surgery. In contrast, AOC carries a high risk of local relapses, distant metastasis, and a significantly higher mortality rate (30%). Surgical resection remains the primary treatment for adrenal oncocytic neoplasms.

Extracardiac adult-type rhabdomyoma-Report of two cases in dogs.

This report describes the cytologic, histopathologic, and immunohistochemical features of adult-type rhabdomyoma located within the subcutaneous tissue in a 14-year-old female Border Collie (thigh) and a 13-year-old male Mongrel (flank). In both cases, fine-needle aspiration biopsy revealed cluster-forming, epithelial-like polygonal cells with abundant foamy cytoplasm, and moderate to marked anisocytosis and anisokaryosis; therefore, an epithelial tumor was suspected. After surgical excision, tumors underwent histopathologic examination with additional immunohistochemistry. Both tumors were well-demarcated and located within the subcutaneous tissue in the vicinity of the cutaneous muscle. The tumor mass consisted of densely packed round or polygonal cells with distinct vacuolation of the cytoplasm. Tumor cells expressed vimentin, desmin, and NSE and were cytokeratin and α-SMA negative. Based on histologic features and immunophenotyping, adult-type rhabdomyoma was diagnosed in both cases. This study highlights that the cytologic features of rhabdomyoma can be misleading and may suggest an epithelial tumor.

Proteomic analysis of chromophobe renal cell carcinoma and benign renal oncocytoma biopsies reveals shared metabolic dysregulation.

BACKGROUND: This study investigates the proteomic landscapes of chromophobe renal cell carcinoma (chRCC) and renal oncocytomas (RO), two subtypes of renal cell carcinoma that together account for approximately 10% of all renal tumors. Despite their histological similarities and shared origins, chRCC is a malignant tumor necessitating aggressive intervention, while RO, a benign growth, is often subject to overtreatment due to difficulties in accurate differentiation. METHODS: We conducted a label-free quantitative proteomic analysis on solid biopsies of chRCC (n = 5), RO (n = 5), and normal adjacent tissue (NAT, n = 5). The quantitative analysis was carried out by comparing protein abundances between tumor and NAT specimens. Our analysis identified a total of 1610 proteins across all samples, with 1379 (85.7%) of these proteins quantified in at least seven out of ten LC‒MS/MS runs for one renal tissue type (chRCC, RO, or NAT). RESULTS: Our findings revealed significant similarities in the dysregulation of key metabolic pathways, including carbohydrate, lipid, and amino acid metabolism, in both chRCC and RO. Compared to NAT, both chRCC and RO showed a marked downregulation in gluconeogenesis proteins, but a significant upregulation of proteins integral to the citrate cycle. Interestingly, we observed a distinct divergence in the oxidative phosphorylation pathway, with RO showing a significant increase in the number and degree of alterations in proteins, surpassing that observed in chRCC. CONCLUSIONS: This study underscores the value of integrating high-resolution mass spectrometry protein quantification to effectively characterize and differentiate the proteomic landscapes of solid tumor biopsies diagnosed as chRCC and RO. The insights gained from this research offer valuable information for enhancing our understanding of these conditions and may aid in the development of improved diagnostic and therapeutic strategies.