FDG PET/CT is not a reliable modality in the diagnosis of RCC with its low sensitivity, but it is effective in the detection of distant metastases and can be used as a complementary tool when conventional imaging studies yield equivocal results.

Adrenal schwannoma is an extremely uncommon cause of incidentaloma. It originates from neural sheath Schwann cells of the adrenal gland. We report the case of a left adrenal schwannoma incidentally discovered in a 32-year-old woman during examination of bloated feeling and stomach ache. The patient was incidentally found to have a left adrenal mass of 9 cm on abdominal ultrasonography. Computed tomography (CT) of the abdomen and [¹⁸F] fluorodeoxyglucose positron emission tomography (PET) were also performed. Metabolic evaluation was unremarkable. Due to the large size of the tumor, left adrenalectomy was performed. The postoperative course was uneventful. Histological examination established the diagnosis of schwannoma. This diagnosis was supported by immunohistochemistry of S-100 and vimentin positivity. In conclusion, adrenal schwannoma is an extremely rare entity and can grow considerably in size. The present case report emphasizes that clinicians should be aware of the possibility of retroperitoneal schwannoma. Total excision of benign schwannoma is associated with a favorable outcome. To our knowledge, there are case reports of schwannoma with CT and magnetic resonance imaging findings in the literature, although this is the first schwannoma case with PET-CT imaging.

Metformin causes an increase in (18)F-FDG uptake in the bowel and stopping metformin before PET/CT study significantly decreased this unwanted uptake, especially in the colon, facilitating the interpretation of images obtained from the abdomen and preventing the obliteration of lesions.

IntroductionGanglioneuromas are rare benign tumors arising from the neural crest tissue and are most commonly located in the posterior mediastinum and retroperitoneum; they are rarely found in the adrenal gland. This tumor is usually asymptomatic and in the majority of cases is detected incidentally. Although the characteristics of adrenal ganglioneuroma on computerized tomography and magnetic resonance imaging have been well described, the exact diagnosis is difficult. Histopathological examination is currently the mainstay of diagnosis. Ganglioneuromas have a very good prognosis with surgical removal. We report the case of a male patient with an incidentally identified adrenal ganglioneuroma with high standardized uptake values in a positron emission tomography scan.Case presentationAn 18-year-old Turkish male patient with no previous comorbidities was admitted to our hospital with lower-quadrant pain. He had no significant past medical or surgical history. A physical examination did not reveal any signs and the results of routine laboratory tests were all within the normal ranges. Our patient underwent computed tomography of his abdomen, which showed a relatively homogenous left adrenal tumor measuring 5.2×4.3×7.1cm. On a positron emission tomography scan, the left adrenal gland disclosed a standardized uptake value of 4.1. Our patient underwent an exploratory laparotomy with left adrenalectomy without any related complications.ConclusionGanglioneuroma may sometimes be similar to other adrenal malignancies. Careful evaluation with endocrine tests and imaging procedures is necessary to provide an accurate diagnosis. Definitive diagnosis can be made by histological examination. The prognosis is very good with surgical removal.

(18)F-FDG-PET/CT is more sensitive than BS in detecting bone metastasis in patients with neoplastic diseases. (18)F-FDG-PET/CT has the advantage of detecting unknown primary cancers and visceral metastases besides bone metastases.

A 29-year-old female patient who was being followed up for differentiated papillary thyroid carcinoma was referred to us for exploration of any possible metastasis since her serum thyroglobulin levels were high. The patient underwent an F-18 fluorodeoxyglucose positron emission tomography study, and a pathologically increased FDG uptake at the left lower abdomen was detected corresponding to a solid, cystic lesion on CT images. The patient had a history of primary amenorrhea and, together with the magnetic resonance imaging findings of absent uterus, short and blind end vagina, a diagnosis of androgen insensitivity syndrome was made. The patient underwent laparoscopic left pelvic mass resection, and the histopathology of the lesion revealed Sertoli-Leydig cell tumor.

Objective In patients with metastatic castration-resistant prostate cancer (mCRPCa), enzalutamide is administered when docetaxel treatment fails. The purpose of the study was to evaluate the relationship between prostate-specific antigen (PSA) response and metabolic parameters obtained from 68Ga-PSMA PET/CT before treatment in this patient group. Methods From February 2018 to May 2020, 34 patients with mCRPCa were enrolled in this study. The association between PSA response (at least 50% decrease compared to the pretreatment value) and quantitative prostate-specific membrane antigen (PSMA) expression parameters such as SUVmax, SUVmean, PSMA-TV (PSMA receptor-expressing tumor volume) and TL-PSMA (total lesion PSMA receptor expression) were evaluated. Results Mean SUVmax, SUVmean, PSMA receptor-expressing tumor volume (PSMA-TV) and total lesion PSMA receptor expression (TL-PSMA) values were 33.66 ± 20.42; 8.82 ± 5.03; 319.85 ± 615.12 cm3; and 2894.76 ± 5195.13, respectively. In the posttreatment 12th week, 22 patients (64.7%) had PSA response, while 12 patients (35.3%) were nonresponders. In patients with PSA response, PSMA-TV values were significantly lower than nonresponders (78.37 ± 80.99 cm3 vs. 451.58 ± 734.61 cm3; P = 0.028). But there was no significant difference between responders and nonresponders in terms of age, ISUP grade, SUVmax, SUVmean, TL-PSMA, pretreatment PSA values, presence of local recurrence or metastases at any site. Conclusion PSMA-TV values on 68Ga-PSMA PET/CT imaging before starting enzalutamide treatment following docetaxel failure can predict PSA response in patients with mCRPCa.

Objective: We aimed to assess the role of Magnetic Resonance Imaging (MRI) and X-Ray in the evaluation of response to radiosynovectomy (RS) in patients with hemophilic arthropathy.Material and Methods: Eleven patients who suffered from hemophilic arthropathy with a mean age of 11.7 (range between 7-15) were included in this study. 148-185 MBq Yttrium 90 silicate (Y-90) was administered intraarticularly to ten knee joints and one patient was treated with intraarticular 74 MBq Rhenium 186 (Re-186) injection into his ankle. Before radiosynovectomy, plain anteroposterior and lateral X-rays of the target joints were obtained by standard technique. The follow-up MRI and X-ray studies of the patients were done 6 months after RS. Pettersson hemophilic arthropathy scales were utilized to stage the condition of the joints on plain X-ray and classification of the investigated joints on MRI were done according to Denver score. The clinical assessment of the efficacy of the RS was made with the comparison of the average bleedings before and after the intervention. Results: During the 6-month follow-up period after RS, an improvement in number of hemarthrosis 75% or greater compared with the prior six months occurred in six joints (54.5%). The Pettersson scores worsened in 1/11 (9%), remained unchanged in 9/11 (81.8%), and improved in 1/11 (9%) joints. At the 6-month follow-up, the MRI score worsened in one (9%) and was unchanged in 10/11 joints (90.9%). Conclusion: MRI is a more sensitive tool than plain radiography for evaluating and follow-up of joint disease in persons with hemophilia, but both methods don’t show correlation with the therapeutic responseConflict of interest:None declared.