Metastatic urinary bladder paraganglioma on Ga-68 DOTATATE PET/CT

Paragangliomas are extra-adrenal catecholamine-secreting neuroendocrine tumors that can present with adrenergic signs and symptoms. The urinary bladder is a rare location for a paraganglioma, and these tumors must be distinguished from other more common bladder neoplasms. In this case report, we discuss a 59 year-old woman who initially presented with tachycardia, palpitations, chest tightness, shortness of breath, and weight loss. Laboratory evaluation showed significantly elevated catecholamines in the plasma and urine. A CT (Computed Tomography) scan of the abdomen and pelvis revealed an enhancing mass arising from the urinary bladder and an enlarged right pelvic lymph node. A follow up Ga-68 DOTATATE PET/CT (Positron Emission Tomography and/or Computed Tomography) showed increased uptake in the primary bladder mass, right pelvic lymph node, numerous skeletal lesions, and pulmonary nodules, consistent with metastatic paraganglioma of the urinary bladder. This case report demonstrates the radiological findings of metastatic urinary bladder paraganglioma and highlights the importance of skull base to mid-thigh PET/CT using Ga-68 DOTATATE. It is crucial for the radiologist to be familiar with the characteristics of urinary bladder paragangliomas and identify these tumors on imaging to allow prompt initiation of surgical resection and/or systemic therapy.     

18F-FDG PET or PET/CT for detecting extrahepatic metastases or recurrent hepatocellular carcinoma: a systematic review and meta-analysis

Aim

Positron emission tomography (PET) using F18-flurodeoxy-glucose (FDG) has been widely used for reflecting cellular metabolism. However, the feasibility of FDG PET in the diagnosis of hepatocellular carcinoma (HCC) is limited. The aim of the study was to assess the ability of FDG PET (PET/CT) in the detection of extrahepatic metastases or recurrent HCC.

Materials and methods

We conducted MEDLINE, EMBASE and COCHRANE searches (last update, April 2011). Eight eligible articles were identified evaluating F18-FDG PET (PET/CT) in extrahepatic metastases or recurrent HCC. Two authors independently evaluated the methodological quality of each study. We estimated pooled sensitivities, specificities, summary receiver-operating-characteristic (SROC) curves, and summary likelihood ratios.

Results

Eight eligible studies were enrolled in this study. The pooled estimates of sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of FDG PET (PET/CT) in the detection of metastatic HCC were 76.6%, 98.0%, 14.68, and 0.28, respectively. The pooled estimates of sensitivity, specificity, LR+ and LR− of FDG PET (PET/CT) in the detection of recurrent HCC were 81.7%, 88.9%, 4.72, and 0.19, respectively.

Conclusion

Based on the results of this systematic review, F-18 FDG PET (PET/CT) was useful in ruling in extrahepatic metastases of HCC and valuable for ruling out the recurrent HCC.     

Post-therapy surveillance of patients with uterine cancers: value of integrated FDG PET/CT in the detection of recurrence

PURPOSE: The purpose of this study was to prospectively determine the diagnostic accuracy of PET/CT in the detection of recurrence in patients with treated uterine cancers. METHODS: Twenty-five women, ranging in age from 37 to 79 years (mean 58.9 years), who underwent primary surgical treatment for either a cervical or an endometrial cancer met the inclusion criterion of the study, which was suspicion of recurrence based on results of routine follow-up procedures. PET/CT was performed after administration of 18F-fluorodeoxyglucose (FDG); two readers interpreted the images in consensus. Histopathological findings or correlation with results of subsequent clinical and imaging follow-up examinations served as the reference standard. Diagnostic accuracy of PET/CT was reported in terms of the proportion of correctly classified patients and lesion sites. RESULTS: Tumour recurrence was found at histopathological analysis or follow-up examinations after PET/CT in 14 (56%) of the 25 patients. Patient-based sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET/CT for detection of tumour recurrence were 92.9%, 100.0%, 100.0%, 91.7% and 96.0%, respectively. Lesion site-based sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET/CT were 94.7%, 99.5%, 94.7%, 99.5% and 99.0%, respectively. CONCLUSION: This preliminary study shows that PET/CT may be an accurate method for the evaluation of recurrence in patients who have been treated for uterine cancers and are undergoing follow-up.     

Atypical metastatic lung cancer of the right ventricle on FDG PET/CT

Although primary cardiac tumours are extremely uncommon, secondary tumours or cardiac metastasis are not. We present a 68-year-old gentleman with squamous cell carcinoma of the right lower lobe with bony metastasis to the right clavicle who was treated with radiotherapy to the lung and clavicle as well as combination immunotherapy (Pembrolizumab) and chemotherapy (Carboplatin/Paclitaxel). Despite completing the above treatment regime, ¹⁸F-FDG PET/CT scan showed progression with two new sites of metastasis including a focus in the lateral wall of the right ventricle which correlate to a soft tissue density mass on CT as well as a FDG avid mass in the left masseter. Identification of cardiac lesions with ¹⁸F-FDG PET/CT maybe challenging with routine preparation due high physiological FDG uptake in the myocardium and significant variability, nevertheless, focal FDG uptake in the heart should be carefully assessed for the possibility of cardiac metastasis.     

FDG avidity and PET/CT patterns in primary gastric lymphoma

PURPOSE: The use of 18F-fluoro-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in primary gastric lymphoma (PGL) is challenging due to physiologic FDG activity in the stomach and variability in the degree of uptake in various histologic subtypes. This study assesses FDG avidity and PET/CT patterns in newly diagnosed PGL. METHODS: Sixty-two PET/CT studies of newly diagnosed PGL were reviewed (24 low-grade mucosa-associated lymphoid tissue [MALT], 38 aggressive non-Hodgkin's lymphoma [AGNHL]). FDG avidity, patterns (focal/diffuse), and intensity (visually vs. the liver and SUVmax) were assessed and compared to 27 controls. Gastric CT abnormalities and extragastric sites were recorded. RESULTS: Gastric FDG uptake was found in 55/62 (89%) PGL (71% MALT vs. 100% AGNHL, p < 0.001) and 63% controls. A diffuse pattern was found in 60% PGL (76% MALT vs. 53% AGNHL, p = NS) and 47% controls. FDG uptake higher than liver was found in 82% PGL (58% MALT vs. 97% AGNHL, p < 0.05) and 63% controls. SUVmax in FDG-avid PGLs was 15.3 +/- 11.7 (5.4 +/- 2.9 MALT vs. 19.7 +/- 11.5 AGNHL, p < 0.001) and 4.6 +/- 1.4 in controls. CT abnormalities were found in 79% PGL (thickening, n = 49; ulcerations, n = 22). Extra-gastric FDG-avid sites were seen in none of MALT, but 61% of AGNHL (nodal, n = 18; nodal and extranodal, n = 5). CONCLUSIONS: FDG avidity was present in 89% of PGLs, including all patients with AGNHL but only 71% of MALT. FDG uptake can be differentiated, in particular in AGNHL-PGL, from physiologic tracer activity by intensity but not by pattern. Extragastric foci on PET and structural CT abnormalities are additional parameters that can improve PET/CT assessment of PGL. Defining FDG avidity and PET/CT patterns in AGNHL and a subgroup of MALT-PGL before treatment may be important for further monitoring therapy response.     

Evaluation of Adrenal Masses in Lung Cancer Patients Using F-18 FDG PET/CT

Purpose

The aim of this study was to assess the diagnostic efficacy of PET/CT using various parameters for the characterization of adrenal nodules in lung cancer patients.

Methods

Sixty-one adrenal nodules in 51 lung cancer patients were evaluated. The final diagnosis was based on histology (n = 2) or imaging follow-up (n = 59, range of follow-up: 7–57 months, median 27 months). Each adrenal nodule was analyzed using four parameters of PET/CT: the maximum standardized uptake value (SUV_max), the adrenal nodule/liver ratio of the SUV (SUV ratio), Hounsfield units (HU) and size. The optimal cutoff of each parameter for the identification of metastatic nodule was determined by ROC analysis and then the diagnostic efficacy was compared among the parameters.

Results

Of the 61 adrenal nodules, 45 (73%) were considered metastasis. The optimal cutoff values of the parameters were SUV_max >2.7, SUV ratio >1.3, HU >18 and size >20 mm, respectively. The sensitivity, specificity and accuracy by SUV_max >2.7 were 88.9%, 87.5% and 88.5%, and those by SUV ratio >1.3 were 84.4%, 100% and 88.5%, respectively. The combination of SUV ratio >1.3 and HU >18 had sensitivity of 97.7%, specificity of 81.2% and accuracy of 93.4% to predict adrenal metastasis in patients with lung cancer.

Conclusion

SUV ratio from F-18 FDG PET/CT could identify the adrenal metastasis in lung cancer patients. The combination of SUV ratio and HU can improve the accuracy of differentiating benign and metastatic adrenal lesions in lung cancer patients.     

Comparative study of FDG PET/CT and conventional imaging in the staging of rhabdomyosarcoma

Objective  The current study was conducted to compare the diagnostic accuracy between ¹⁸F-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET)/computed tomography (CT), and conventional imaging (CI) for the staging and re-staging of patients with rhabdomyosarcomas. Methods  Thirty-five patients who underwent FDG PET/CT prior to treatment were evaluated retrospectively. CI methods consisted of ^99mTc-hydroxymethylene diphosphonate bone scintigraphy, chest radiograph, whole body CT, and magnetic resonance imaging of the primary site. The images were reviewed and two boardcertified radiologists reached a diagnostic consensus. Tumor stage was confirmed by histological examination and/or follow-up examinations. Results  Interpretation on the basis of FDG PET/CT, and CI, diagnostic accuracies of the T and N stages were similar. Using FDG PET/CT, the M stage was correctly assigned in 31 patients (89%), whereas the accuracy of CI in M stage was 63%. TNM stage was correctly assessed with FDG PET/CT in 30 of 35 patients (86%) and with CI in 19 of 35 patients (54%). The overall TNM staging and M staging accuracies of FDG PET/CT were significantly higher than that of CI (P < 0.01). Conclusions  FDG PET/CT is more accurate than CI regarding clinical staging and re-staging of patients with rhabdomyosarcomas.     

Abdominal Mesh Implant Showing FDG Uptake on PET/CT

F-18 fluorodeoxyglucose (FDG) uptake by a mesh implant might be caused by a foreign body granulomatous reaction with inflammation and fibrosis, which can be demonstrated by positron emission tomography/computed tomography (PET/CT). A 71-year-old man underwent F-18 FDG PET/CT for the follow-up evaluation after an operation for colonic adenocarcinoma. On PET/CT imaging, there was a rectangular-shaped FDG uptake (maximal standardized uptake value, maxSUV: 3.4) in the anterior abdominal wall. On the review of the medical records, the patient had a history of herniorrhapy for the reinforcement of the abdominal wall 2 months previously, using a mesh implant consisting of polytetrafluoroethylene (Teflon). We report a case of FDG uptake associated with surgical procedures including mesh implant on F-18 FDG PET/CT.     

Bone metastasis in patients with non-small cell lung cancer: The diagnostic role of F-18 FDG PET/CT

Purpose

To evaluate the performance of F-18 FDG PET/CT in the detection of bone metastasis in non-small cell lung cancer (NSCLC) patients.

Materials and methods

Three hundred and sixty-two consecutive NSCLC patients who underwent F-18 FDG PET/CT scanning were retrospectively analyzed. Each image of PET/CT, combined CT, and PET was performed at 10 separate areas and interpreted blindly and separately. The sensitivity, specificity and accuracy of F-18 FDG PET/CT, combined CT and F-18 FDG PET were calculated and the results were statistically analyzed.

Results

Bone metastasis was confirmed in 82 patients with 331 positive segments based on the image findings and clinical follow-up. On patient-based analysis, the sensitivity of F-18 FDG PET/CT (93.9%) was significantly higher than those of combined CT (74.4%) and F-18 FDG PET (84.1%), respectively (p < 0.05). The overall specificity and accuracy of combined CT, F-18 FDG PET, and F-18 FDG PET/CT were 90.7%, 93.2%, 98.9% and 87.0%, 91.2%, and 97.8%, respectively (compared with PET/CT, p < 0.05). On segment-based analysis, the sensitivity of the three modalities were 79.5%, 94.3%, and 98.8%, respectively (compared with PET/CT, p < 0.05). The overall specificity and accuracy of the three modalities were 87.9%, 89.2%, 98.6% and 84.5%, 91.2%, 98.7%, respectively (compared with PET/CT, p < 0.05).

Conclusion

F-18 FDG PET/CT is superior to F-18 FDG PET or combined CT in detecting bone metastasis of NSCLC patients because of the complementation of CT and PET. It is worth noting that the added value of F-18 FDG PET/CT may beneficially impact the clinical management of NSCLC.     

Nonfunctioning Periurethral Paraganglioma Incidentally Detected by FDG PET/CT

Paragangliomas are extra-adrenal neuroendocrine tumors that are derived from neural crest cells. Among all the paragangliomas, those in a pelvic location are extremely rare. In addition, the prevalence of nonfunctioning paragangliomas is underestimated because of their clinical latency, and they are often underdiagnosed unless they cause symptoms. We report a case of a nonfunctioning periurethral paraganglioma that was incidentally detected by FDG PET/CT during regular follow-up after excision of a melanoma on the left thumb.     

Uterine Epithelioid Angiosarcoma on F-18 FDG PET/CT

Uterine epithelioid angiosarcoma can have conventional imaging characteristics similar to those of other uterine tumors, such as leiomyoma, leiomyosarcomas or hemangioendothelioma. Uterine epithelioid angiosarcoma exhibiting increased fluorine-18 fluorodeoxyglucose (F-18 FDG) activity can be misdiagnosed. A 61-year-old woman who was diagnosed with uterine epithelioid angiosarcoma underwent F-18 FDG positron emission tomography/computed tomography (PET/CT) as a part of the pretreatment work up for surgery. F-18 FDG PET/CT showed an intense F-18 FDG uptake in the uterus in addition to increased F-18 FDG uptake at the paraaortic and aortocaval lymph nodes. To our knowledge, this is the first case report of intense F-18 FDG uptake in uterine epithelioid angiosarcoma in Korea.     

Hypermetabolic Axillary Mass on 18F FDG PET/CT: Breast Cancer Arising from Accessory Breast Tissue

Differential diagnosis among several causes of axillary malignant mass is important. The most common cause of palpable malignant axillary mass is metastatic lymphadenopathy. Although carcinoma arising from ectopic breast tissue is rare, the diagnosis should be kept in mind when evaluating malignant axillary mass. In this report we present a case with carcinoma arising from ectopic breast tissue. ¹⁸F FDG PET/CT was performed for the purpose of localizing primary breast cancer lesion and systemic evaluation. PET/CT showed hypermetabolic lesions only in the right axilla. There is no evidence of malignancy in both breasts. When nuclear physicians encounter a hypermetabolic axillary mass indicating malignant lesion without evidence of primary breast malignant lesion, carcinoma arising from ectopic breast tissue should be included in the differential diagnosis.     

18F-FDG PET or PET/CT for detection of metastatic lymph nodes in patients with endometrial cancer: A systematic review and meta-analysis

The present study assessed the diagnostic performances of 18F-FDG PET or PET/CT in detecting pelvic and/or paraaortic lymph node metastasis in patients with endometrial cancer. METHODS: Through a search of MEDLINE (January 1998 to March 2011), an overall weighted average for sensitivity and specificity as well as pooled estimates of positive and negative likelihood ratios were calculated. A summary receiver-operating-characteristics (sROC) curve was constructed and the area under the sROC curve (AUC) was calculated. I-square was calculated to explore heterogeneity. RESULTS: The present study included 243 patients from seven studies. Results indicated a lack of significant heterogeneity for sensitivity and specificity (I(2)<50% and p>0.05). The overall pooled estimates for sensitivity and specificity of FDG-PET or PET/CT scans in the detection of pelvic and/or paraaortic metastasis were 63.0% (95% CI, 48.7-75.7%) and 94.7% (95% CI, 90.4-97.4%), respectively. The positive likelihood ratio was 10.465 (95% CI, 5.646-19.396) and the negative likelihood ratio 0.399 (95% CI, 0.284-0.560). The AUC was 0.9533. The overall diagnostic accuracy (Q* index) was 89.5%. Conclusion The high positive likelihood value confirms the reliability of a positive FDG-PET or PET/CT to detect pelvic and/or paraaortic lymph nodes metastasis in patients with untreated endometrial cancer. FDG-PET or PET/CT may prove beneficial to surgeons when selecting appropriate patients on whom to perform lymphadenectomy.     

Performance of integrated FDG-PET/contrast-enhanced CT in the diagnosis of recurrent uterine cancer: comparison with PET and enhanced CT

Purpose  To evaluate the accuracy of integrated positron emission tomography and computed tomography (PET/CT) with iodinated contrast agent and ¹⁸F-fluorodeoxyglucose (FDG) in the diagnosis of suspected uterine cancer recurrence and to assess the impact of PET/CT findings on clinical management, compared with PET alone and enhanced CT alone. Methods  Of 103 women who had undergone treatment for histopathologically proven uterine cervical or endometrial cancer, 90 underwent FDG-PET/contrast-enhanced CT examination for suspected recurrence. PET-alone, CT-alone, and fused PET/CT images were interpreted by two radiologists by consensus for each investigation. Lesion status was determined on the basis of histopathology, radiological imaging and clinical follow-up for longer than 6 months. Differences among the three modalities were tested using the Cochran Q test, followed by multiple comparisons using the McNemar test with Bonferroni adjustment. Results  Patient-based analysis showed that the sensitivity, specificity, and accuracy of PET alone were 79.5% (35/44), 73.9% (34/46), and 76.7% (69/90), respectively, whereas those of CT alone were 68.2% (30/44), 87.0% (40/46), and 77.8% (70/90), respectively, and those of PET/CT were 90.9% (40/44), 93.5% (43/46), and 92.2% (83/90), respectively. PET/CT findings resulted in a change of management in 38 of the 90 patients (42%) with an additional effect on patient management in 13 patients (14%) diagnosed by CT alone and 14 patients (16%) diagnosed by PET alone. Conclusion  FDG-PET/contrast-enhanced CT is a more accurate modality for assessing recurrence of uterine cancer, and led to more appropriate subsequent clinical management than that resulting from PET alone or enhanced CT alone.     

Evaluation of the efficiency of FDG PET/CT in detection and characterization of skeletal metastases

Background and purpose

Combined PET/CT using 18F-FDG is widely used in evaluation of various malignancies; in their initial staging and more efficiently in their follow up; hence, the importance of evaluation of its diagnostic role in the imaging of skeletal metastases. The purpose of this study is to evaluate precisely the efficiency of FDG PET/CT in detection and characterization of osseous metastatic lesions compared to isolated PET and CT in various malignancies.

Patients and methods

The study included 123 patients divided into seven groups of malignancies to whom PET/CT was done. In this study population, a detailed retrograde lesion based analysis was performed for a total of 1705 detected bone lesions on PET, CT and fused PET/CT images. Sensitivity, specificity, PPV and NPV of each modality were calculated. Semi-quantitative and ROC curve analysis of the lesions were performed to study the relationship between the lesion’s SUV and its corresponding morphologic pattern on CT and to set a reliable SUV_max cut-off value that can predict the presence of malignant lesion.

Results

The calculated fused PET/CT sensitivities and specificities in various malignancies ranged from 95.2% to 99.6% and 75% to 100%, respectively. The combined PET/CT has significantly improved the low CT sensitivity (especially in lymphoma) as well as both CT and PET specificities. Our ROC analysis suggested using SUV_max of 3 as a cut off value for malignant osseous lesions.

Conclusion

Fused PET/CT was highly efficient in evaluation of skeletal metastases with superior performance in: detection of early bone marrow infiltration not apparent on CT, resolution of metabolic activity before definite signs of complete healing on CT, detection of missed sclerotic metastases on PET due to their relatively low metabolic activity, detection of intra and extra osseous recurrence and differentiation of benign from malignant bone lesions.     

Integrated PET/CT in the preoperative staging of lung cancer: A prospective comparison of CT,PET and integrated PET/CT

Purpose

The purpose of this study was to evaluate the role of integrated PET/CT in the staging of lung cancer compared with CT alone or PET alone.

Materials and methods

Thirty-three patients underwent integrated PET/CT for the staging of lung cancer. The tumor, node and metastasis (TNM) stages were assessed with CT, PET and integrated PET–CT and compared with the surgical and pathological staging.

Results

CT correctly evaluated the (T) status in (64%) of the patients, PET in (59%) and PET/CT in (86%). CT correctly evaluated the (N) status in (73%) of the patients, PET in (76%), and PET/CT (88%) with accuracy, sensitivity, specificity, PPV and NPV were 73%, 78%, 71%, 50% and 94% for CT, 76%, 67%, 79%, 55% and 95% for PET and 88%, 89%, 88%, 73% and 100% for PET/CT respectively, and for (M) status were 91%, 86%, 92%, 75% and 96% for CT, 88%, 71%, 92%, 71% and 92% for PET and 97%, 100%, 96%, 88% and 100% for PET/CT respectively. Regarding the overall TNM staging CT correctly staged 24 patients. PET correctly staged 23 cases while PET/CT correctly staged 30 cases. A significant difference in the accuracy of overall tumor staging between PET/CT and CT (P = 0.0412) or PET (P = 0.0233).

Conclusion

The integrated PET/CT is superior to either CT or PET in the staging of lung cancer which has an important impact on selection of the appropriate treatment regimen.     

Rosai-Dorfman Disease: Importance of 18F FDG PET/CT to Determine Extension and Extranodal Involvement

Rosai-Dorfman disease or sinus histiocytosis with lymphadenopathy is a rare benign histiocytic proliferative disorder of unknown etiology first described in 1969. It typically affects older females and most common presentation is with massive lymphadenopathy and nonspecific systemic symptoms; therefore, it is often confused with lymphoproliferative disorders [1, 2]. We present the case of a 69-year-old woman with nasal obstruction as only complaint. Laboratory tests showed normal leukocyte count with elevated ANC (absolute neutrophil count), normal RBC count with normal MCV (mean corpuscular volume) and MCH (mean corpuscular hemoglobin), elevated ESR (erythrocyte sedimentation rate), and normal IgG, IgA, and IgM values. Evaluation revealed a nasopharyngeal mass, which was biopsied and reported emperipolesis with positive CD68 and S-100; typical and differential findings of this disease [1, 2]. ¹⁸F FDG PET/CT was performed to determine the extent and involvement of the disease. Considering the presence of few symptoms and no significant laboratory abnormality, treating physicians decided to start a regimen of corticosteroids (prednisolone) for a period of 4 months, after which a follow-up with ¹⁸F FDG PET/CT will be performed.     

Thin-section CT of the mediastinum in preoperative N-staging of non-small cell lung cancer: Comparison with FDG PET

Purpose

To compare diagnostic capability of preoperative N-staging of lung cancer between thin-section CT of the mediastinum and FDG PET, and 5 mm slice thickness CT.

Materials and methods

The subjects were 34 patients with lung carcinoma who were examined by both CT and PET, and subsequently underwent surgery between May 2005 and January 2007. CT was carried out with a 16 detector row helical CT scanner. The raw data were reconstructed into 5 mm slice thickness and 1 mm slice thickness (thin-section CT). A total of 251 lymph node stations were retrospectively assessed for the presence of lymph node metastasis with thin-section CT, 5 mm CT and PET. In the interpretations of thin-section CT and 5 mm CT, we employed multi-criteria as follows: nodular calcification and intranodal fat as benign criteria, and short-axis diameter more than 10 mm (size criterion), focal low density other than fat, surrounding fat infiltration and convex margin in hilar lymph nodes, as malignant criteria. On PET, maximum standardized uptake value (SUVmax) of 2.5 or more was used as the criterion of malignancy. Sensitivity and specificity were compared between these examinations using McNemar test.

Results

Sensitivities and specificities of thin-section CT, 5 mm CT and PET were 25%, 25%, 25%, and 97%, 94%, 98%, respectively. The statistical analysis revealed that the specificity of 5 mm CT was significantly lower than those of thin-section CT (p = 0.039) and PET (p = 0.006), while no difference was present between thin-section CT and PET.

Conclusion

Thin-section CT of the mediastinum using multiple criteria was comparable to PET in preoperative N-staging of lung cancer.     

Retroperitoneal Pleomorphic Liposarcoma Mimicking Adrenal Cancer in F-18 FDG PET/CT

Liposarcoma is the second most common type of soft tissue sarcoma, but pleomorphic liposarcoma is the least common subtype. We present the case of a 42-year-old man who had experienced intermittent left flank pain for a month. A large soft-tissue mass was detected by ultrasonography in a local clinic, and he was referred for further evaluation. Positron emission tomography/computed tomography (PET/CT) with F-18 fluoro-2-deoxy-D-glucose (F-18 FDG) showed intense uptake in the retroperitoneal mass, which mimicked an adrenal cancer. The patient underwent left radical nephroadrenalectomy, and the tumor was revealed to be a pleomorphic liposarcoma upon pathological examination. When there is a large retroperitoneal mass with intense F-18 FDG activity, the possibility of a pleomorphic liposarcoma should be considered.