Objective To investigate the causes of false-positive results in the ⁶⁸Ga-labeled fibroblast activation protein inhibitor (⁶⁸Ga-FAPI-04) PET/CT imaging. Methods The imaging data of 547 patients undergoing ⁶⁸Ga-FAPI-04 PET/CT examination in the Department of Nuclear Medicine of the Affiliated Hospital of Southwest Medical University from September 2020 to May 2021 were retrospectively collected.Two experienced nuclear medicine diagnostic physicians analyzed the clinical data,relevant imaging examinations,laboratory examinations,pathological results and follow-up results of the patients with false-positive results. Results The ⁶⁸Ga-FAPI-04 PET/CT imaging of 547 patients showed false-positive results in 99 (18.1%) patients,including 56 males and 43 females.The postoperative pathological examination confirmed false-positive results in 13 patients,including 1 patient of thyroiditis,2 patients of pulmonary tuberculosis,1 patient of bone tuberculosis,2 patients of pulmonary inflammatory pseudotumor,1 patient of pulmonary sarcoidosis,1 patient of pulmonary benign fibroma,1 patient of organic pneumonia,2 patients of renal angiomyolipoma,1 patient of mass pancreatitis,and 1 patient of pancreatic mucinous cystadenoma.The medical history,relevant imaging examination,and long-term follow-up confirmed false-positive results in 86 patients.Specifically,the false-positive uptake in the neck,chest,abdomen,bone joint,and skin occurred in 8 (9.3%),13 (15.1%),5 (5.8%),57 (66.3%),and 3 (3.5%) patients,respectively.Inflammation-related uptake appeared in 83 (83.8%) patients with false-positive imaging results,of which arthritis (23 patients) and osteophyte (29 patients) were the most common.Sixteen (16.2%) patients showed the false-positive uptake related to fibroblasts. Conclusion ⁶⁸Ga-FAPI-04 PET/CT imaging will show non-malignant tumor false-positive results,which are mainly associated with inflammation and fibroblasts.
Female ; Male ; Humans ; Gallium Radioisotopes ; Positron Emission Tomography Computed Tomography ; Angiomyolipoma ; Retrospective Studies ; Kidney Neoplasms ; Fibroblasts ; Inflammation ; Fluorodeoxyglucose F18 ; Quinolines

Objective: To investigate the expression of glycoprotein non metastatic melanoma protein B (GPNMB) in renal eosinophilic tumors and to compare the value of GPNMB with CK20, CK7 and CD117 in the differential diagnosis of renal eosinophilic tumors. Methods: Traditional renal tumor eosinophil subtypes, including 22 cases of renal clear cell carcinoma eosinophil subtype (e-ccRCC), 19 cases of renal papillary cell carcinoma eosinophil subtype (e-papRCC), 17 cases of renal chromophobe cell carcinoma eosinophil subtype (e-chRCC), 12 cases of renal oncocytoma (RO) and emerging renal tumor types with eosinophil characteristics [3 cases of eosinophilic solid cystic renal cell carcinoma (ESC RCC), 3 cases of renal low-grade eosinophil tumor (LOT), 4 cases of fumarate hydratase-deficient renal cell carcinoma (FH-dRCC) and 5 cases of renal epithelioid angiomyolipoma (E-AML)], were collected at the Affiliated Drum Tower Hospital of Nanjing University Medical School from January 2017 to March 2022. The expression of GPNMB, CK20, CK7 and CD117 was detected by immunohistochemistry and statistically analyzed. Results: GPNMB was expressed in all emerging renal tumor types with eosinophil characteristics (ESC RCC, LOT, FH-dRCC) and E-AML, while the expression rates in traditional renal eosinophil subtypes e-papRCC, e-chRCC, e-ccRCC and RO were very low or zero (1/19, 1/17, 0/22 and 0/12, respectively); the expression rate of CK7 in LOT (3/3), e-chRCC (15/17), e-ccRCC (4/22), e-papRCC (2/19), ESC RCC (0/3), RO (4/12), E-AML(1/5), and FH-dRCC (2/4) variedly; the expression of CK20 was different in ESC RCC (3/3), LOT(3/3), e-chRCC(1/17), RO(9/12), e-papRCC(4/19), FH-dRCC(1/4), e-ccRCC(0/22) and E-AML(0/5), and so did that of CD117 in e-ccRCC(2/22), e-papRCC(1/19), e-chRCC(16/17), RO(10/12), ESC RCC(0/3), LOT(1/3), E-AML(2/5) and FH-dRCC(1/4). GPNMB had 100% sensitivity and 97.1% specificity in distinguishing E-AML and emerging renal tumor types (such as ESC RCC, LOT, FH-dRCC) from traditional renal tumor types (such as e-ccRCC, e-papRCC, e-chRCC, RO),respectively. Compared with CK7, CK20 and CD117 antibodies, GPNMB was more effective in the differential diagnosis (P<0.05). Conclusion: As a new renal tumor marker, GPNMB can effectively distinguish E-AML and emerging renal tumor types with eosinophil characteristics such as ESC RCC, LOT, FH-dRCC from traditional renal tumor eosinophil subtypes such as e-ccRCC, e-papRCC, e-chRCC and RO, which is helpful for the differential diagnosis of renal eosinophilic tumors.
Humans ; Kidney Neoplasms/pathology* ; Carcinoma, Renal Cell/pathology* ; Diagnosis, Differential ; Angiomyolipoma/diagnosis* ; Biomarkers, Tumor/metabolism* ; Leukemia, Myeloid, Acute/diagnosis* ; Membrane Glycoproteins

Renal angiomyolipoma (AML) with renal vein, inferior vena cava (IVC), and right atrial embolism is a rare solid tumor, whose etiology and pathogenesis are still unclear. Moreover, it is often misdiagnosed. One patient with renal AML complicated with renal vein, IVC, and right atrial embolism was admitted to the Second Xiangya Hospital of Central South University, who was a 35-year-old female, without any previous medical history, presented with right low back pain for more than 3 years. Computed tomography (CT) scan showed irregular lobulated fatty density mass in the right kidney, renal vein, IVC, and right atrium. The contrast-enhanced scan showed no enhancement of fat components at each phase and mild enhancement of solid components. Radical resection of the right kidney and removal of tumor thrombus were performed, and there was no recurrence 1 year after the operation. It is rare for renal AML to grow along the renal vein, IVC, and extend to the right atrium. Imaging examination is extremely important, and the CT findings of this case are characteristic, but the diagnosis eventually depends on pathological and immunohistochemical examinations.
Female ; Humans ; Adult ; Vena Cava, Inferior/pathology* ; Angiomyolipoma/surgery* ; Atrial Fibrillation ; Kidney Neoplasms/surgery* ; Embolism/pathology* ; Heart Atria/diagnostic imaging* ; Leukemia, Myeloid, Acute/pathology*

OBJECTIVE: To investigate the capabilities of classification models based on hierarchical fusion framework of multi-classifier using a random projection strategy for differentiation of renal cell carcinoma (RCC) from small renal angiomyolipoma (< 4 cm) without visible fat (AMLwvf). METHODS: We retrospectively collected the clinical data from 163 patients with pathologically proven small renal mass, including 118 with RCC and 45 with AMLwvf.Target region of interest (ROI) delineation was performed on an unenhanced phase (UP) CT image slice displaying the largest lesion area.The radiomics features were used to establish a hierarchical fusion method.On the projection-based level, the homogeneous classifiers were fused, and the fusion results were further fused at the classifier-based level to construct a multi-classifier fusion system based on random projection for differentiation of AMLwvf and RCC.The discriminative capability of this model was quantitatively evaluated using 5-fold cross validation and 4 evaluation indexes[specificity, sensitivity, accuracy and area under ROC curve (AUC)].We quantitatively compared this multi-classifier fusion framework against different classification models using a single classifier and several multi-classifier ensemble models. RESULTS: When the projection number was set at 10, the proposed hierarchical fusion differentiation framework achieved the best results on all the evaluation measurements.At the optimal projection number of 10, the specificity, sensitivity, average accuracy and AUC of the multi-classifier ensemble classification system for differentiation between AMLwvf and RCC were 0.853, 0.693, 0.809 and 0.870, respectively. CONCLUSION The proposed model constructed based on a multi-classifier fusion system using random projection shows better performance to differentiate RCC from AMLwvf than the AMLwvf and RCC discrimination models based on a single classification algorithm and the currently available benchmark ensemble methods.
Angiomyolipoma/pathology* ; Carcinoma, Renal Cell ; Diagnosis, Differential ; Humans ; Kidney Neoplasms/pathology* ; Retrospective Studies ; Tomography, X-Ray Computed/methods*

OBJECTIVE: To evaluate the value of Gerota's fascia suspension device in retroperitoneal laparoscopic partial nephrectomy, and to share the operation experience. METHODS: From October 2018 to December 2020, 6 cases of tumor located in the ventral side of the kidney were selected, including 3 males and 3 females, with 3 cases on the right side and 3 cases on the left side, aged 38-60 years, with an average of 52 years. The body mass index (BMI) was 18.3-30.2 kg/m², with an average of 22.9 kg/m². One patient with diabetes mellitus, three patients with renal cysts, and two patients underwent cholecystectomy before. All the patients were found by physical examinations. The course of disease was 7 days to 20 years, with a median time of 1 month. The tumor was in the ventral side of the kidney, 2 cases located in the upper pole, 1 case in the lower pole and 3 cases near the renal hilum. The tumor size was 1.2-7.8 cm, with an average of 4.5 cm. The R.E.N.A.L score was 7 in 1 case, 8 in 3 cases and 9 in 2 cases. After the preoperative examination completed, retroperitoneal laparoscopic partial nephrectomy (Gerota's fascia suspension device) was performed. RESULTS: All the operations were successfully completed. The operation time ranged from 139 to 193 min, with an average of 172 min. The renal artery occlusion time was 7-43 min, with an average of 19 min, only one case was more than 30 min. The blood loss ranged from 10 to 500 mL, with an average of 128 mL. The postoperative hospital stay ranged from 4 to 13 days, with an average of 6.5 days. Postoperative pathology revealed 4 cases of renal angiomyolipoma and 2 cases of renal clear cell carcinoma. The patients were followed up for 2-27 months, with an average of 17 months, without recurrence. CONCLUSION In the operation of retroperitoneal laparoscopic partial nephrectomy, Gerota's fascia suspension device is beneficial to expose the ventral surgical field, and it is convenient for the surgeon to operate with both hands. This technique is an effective method to deal with the ventral renal tumor, which is worthy of promotion.
Angiomyolipoma ; Fascia ; Female ; Humans ; Kidney ; Kidney Neoplasms/surgery* ; Laparoscopy ; Male ; Nephrectomy

Adult ; Angiomyolipoma ; diagnosis ; genetics ; Exons ; genetics ; Humans ; Kidney Neoplasms ; diagnosis ; genetics ; Male ; Mutation ; genetics ; Tuberous Sclerosis ; complications ; Tuberous Sclerosis Complex 2 Protein ; genetics ; Young Adult

Angiomyolipoma (AML) is a rare benign mesenchymal tumor in the liver, which is composed of blood vessels, smooth muscle, and adipose cells. The proportion of each component varies, making a diagnosis difficult. This paper reports a case of AML in the liver without adipose tissue, mimicking a hepatocellular carcinoma (HCC), which was diagnosed by a surgical tissue biopsy. A 65-year-old woman was admitted for an evaluation of a hepatic mass that had been detected by ultrasonography. The serologic markers of viral hepatitis B and C were negative. The liver function tests and alpha fetoprotein level were within the normal limits. Magnetic resonance imaging revealed a 1.9 cm sized mass in segment 6 of the liver with early arterial enhancement and washout on the delayed phase accompanied by a rim-like enhancement, which is similar to the imaging findings of HCC. A frozen section examination during surgery indicated a hepatocellular neoplasm and suggested the possibility of HCC. On the other hand, the final pathologic diagnosis was epithelioid myoid type of AML with no adipose tissue component. The tumor cells were positive for human melanocyte B-45 and negative for cytokeratin and hepatocyte paraffin 1. This paper reports a very rare case of AML without adipose tissue in the liver mimicking HCC that was diagnosed by a surgical tissue biopsy.
Adipose Tissue ; Aged ; alpha-Fetoproteins ; Angiomyolipoma ; Biopsy ; Blood Vessels ; Carcinoma, Hepatocellular ; Diagnosis ; Female ; Frozen Sections ; Hand ; Hepatitis B ; Hepatocytes ; Humans ; Keratins ; Liver Function Tests ; Liver ; Magnetic Resonance Imaging ; Melanocytes ; Muscle, Smooth ; Paraffin ; Ultrasonography

OBJECTIVE: To compare the safety and treatment effectiveness of retroperitoneal laparoscopic tumor aspiration and laparoscopic partial nephrectomy (LPN) in the treatment of renal angiomyolipoma (RAML). METHODS: We retrospectively reviewed the clinical data of patients with pathologically confirmed RAML who received operation between August 2010 and August 2016 in the Department of Urology, Peking University First Hospital. Among them, a series of 121 patients were included in this trial according to the inclusion criteria, of which 74 cases could be collected and followed-up effectively. Based on the detailed surgical route, the 74 patients were divided into groups A and B: group A, which underwent retroperitoneal laparoscopic tumor aspiration, included 43 cases; group B, which received retroperitoneal LPN, included 31 cases. Patient demographics, intraoperative variables and postoperative outcomes were reported and compared between the groups. RESULTS: No statistical difference was detected in both groups before the treatment. Intraoperatively, the mean estimated blood loss was 48.7 mL in group A and 102.9 mL in group B, and the mean operative time was 70.1 min (21.2 min of warm ischemia time included) in group A and 103.6 min (28.5 min of warm ischemia time included) in group B, which were both statistically different. In group A, no complications occurred and yet 2 complications of transfusion and 1 complication of urine leakage were discovered in group B, although all finally recovered only with conservative treatment. A statistical difference was observed in the complication rates. Post-operatively, the mean serum creatinine level was 1.13 mg/dL in group A, and the level was 1.08 mg/dL in group B, in which no evident difference was detected. In a mean 52.6-months' follow-up, a recurrence of 3 cases in group A (7.0%) and a recurrence of 2 cases in group B (6.5%) were reported. No evident difference was also detected between the groups in the tumor recurrence rates. CONCLUSION Due to the improvements in the intraoperative blood loss and operative time, retroperitoneal laparoscopic tumor aspiration may be provided with more potential advantages in the safety, also with equal efficacy of lower tumor recurrence rates when compared with the traditional retroperitoneal LPN in the treatment of RAML.
Angiomyolipoma/surgery* ; Humans ; Kidney Neoplasms/surgery* ; Laparoscopy ; Neoplasm Recurrence, Local ; Nephrectomy ; Retrospective Studies ; Treatment Outcome

Renal angiomyolipoma (AML) is a common benign tumor in the urinary system, mainly composed of adipose tissue, blood vessels and muscle tissue. Renal AML is sporadic in most of patients, while a few are associated with tuberous sclerosis. Classical renal AML occurs predominantly in middle-aged females. Most cases are found incidentally during imaging examinations. The fat content makes AML have unique imaging characteristics and is easy to be identified with other renal tumors. However, the amount of fat varies in each tumor. AML that contains only microscopically detectable fat and whose amount of intratumoral fat may be too small to be identified on unenhanced computed tomography (CT) images is termed minimal fat or fat-poor renal AML, which appears as a high density shadow in the renal parenchyma on unenhanced CT images. Thus, it can be difficult to distinguish it from renal cell carcinoma (RCC) on imaging. Since the imaging findings are atypical, the diagnosis depends on pathological results. In addition, a few of AML can mimic malignant neoplasms. Recent studies suggested that AML might involve to peri-renal or renal sinus fat, regional lymphatics and other visceral organs, as well as inferior vena cava, which further makes the diagnosis more difficult. However, there is currently no reports about involvement of regional limphatics in minimal fat renal AML. In this article, we report a 27-year-old female patient without family history of tuberous sclerosis, who came to visit the hematologist because a high density shadow near the left kidney was found during CT scan which was accompanied by neck, armpits, groin, abdominal cavity and retroperitoneal lymph nodes enlargement. She was suspected of lymphoma in the beginning and transferred to Department of Urology to perform laparoscopic left renal mass and retroperitoneal lymph node excision and pathological examination for a definitive diagnosis. Finally, pathologic results revealed AML. Postoperative continuous lymphatic fistula developed and the retroperitoneal drainage of chylous fluid was 100-200 mL per day, lasting for 12 weeks. The fistula was successfully closed after conservative treatment including fasting and rehydration. This article summaries and discusses the diagnosis and treatment of renal AML with lymph nodes enlargement and the management of postoperative refractory lymphatic fistula by reviewing the related cases and literature.
Adult ; Angiomyolipoma/pathology* ; Carcinoma, Renal Cell/diagnosis* ; Female ; Fistula ; Humans ; Kidney Neoplasms/pathology* ; Lymph Nodes/pathology* ; Middle Aged

Epithelioid angiomyolipoma (EAML) of liver is a rare neoplasm. Hepatic EAML is often misdiagnosed as other neoplasms such as hepatocellular carcinoma due to non-specific clinical and radiologic features. The morphologic features under microscope and immunohistochemistry staining profile are important in the diagnosis EAML. Here, we report a case of 52-year-old man who found 1.2 cm mass in liver by routine checkup. On the impression of hepatocellular carcinoma, lateral sectionectomy of the liver was done. Microscopically, the tumor is composed of predominant epithelioid cells with vascular component and foamy cells. These cells were positive for HMB45, MelanA, and smooth muscle actin and negative for epithelial membrane antigen. The final diagnosis was hepatic EAML.
Actins ; Angiomyolipoma* ; Carcinoma, Hepatocellular ; Diagnosis ; Epithelioid Cells ; Humans ; Immunohistochemistry ; Liver* ; MART-1 Antigen ; Middle Aged ; Mucin-1 ; Muscle, Smooth ; Perivascular Epithelioid Cell Neoplasms