Thoracic SMARCA4-Deficient Undifferentiated Tumor Mimicking a Pleural Mesothelioma on 18F-FDG PET/CT.

ABSTRACT: A 72-year-old woman, who was a nonsmoker, presented with chest distress persisting for over 10 days. Plain chest CT revealed thickening of the left pleura accompanied by hydrothorax. Subsequent 18F-FDG PET/CT showed irregular thickening involving the visceral, parietal, and interlobular pleura on the left side, with diffuse high avidity of 18F-FDG. The left pleural mesothelioma was suspected initially, but pathological examination from biopsied specimen later confirmed a thoracic SMARCA4-deficient undifferentiated tumor.

18 F-FDG PET/CT in Solitary Extramedullary Plasmacytoma of the Penis.

ABSTRACT: A 72-year-old man presented with a painless penile mass for 3 months. Contrast-enhanced CT revealed heterogeneous enhancement, whereas 18 F-FDG PET/CT displayed inhomogeneous 18 F-FDG accumulation in the lesion without other abnormal activity. The histopathological examination from biopsied specimen confirmed the diagnosis of a plasmacytoma. However, the subsequent tests, including serum/urine immunofixation electrophoresis, serum/urine free light chain assay, and bone marrow smear/biopsy, did not show any abnormalities. The conclusive diagnosis was a solitary extramedullary plasmacytoma of the penis.

18 F-FDG PET/CT Findings in Waldenström Macroglobulinemia With Mesentery Involvement.

ABSTRACT: A 74-year-old man presented to the hospital complaining of weight loss, increasing fatigue, and blurred vision. The abdominal ultrasonography initially revealed a massive lesion in the mesentery, which was later confirmed by a contrast-enhanced CT scan. The 18 F-FDG PET/CT scan showed a single, solitary hypermetabolic mass. The patient was finally diagnosed with Waldenström macroglobulinemia with mesentery involvement by the histopathological examination.

18F-FDG PET/CT in a Patient With Epididymo-Testicular Malacoplakia.

ABSTRACT: A 56-year-old man presented with a 2-month history of a mass in the right epididymo-testicular region, which exhibited heterogeneous high avidity for 18F-FDG on PET/CT. Malignant tumor was highly suspected, leading to subsequent right orchiectomy and epididymectomy. Histopathological examination revealed the presence of characteristic Michaelis-Gutmann bodies within von Hansemann macrophages, confirming the diagnosis of malacoplakia.

18F-FDG PET/CT findings in a patient with blastic plasmacytoid dendritic cell neoplasm and post-transplant lymphoproliferative disorder after hematopoietic stem cell transplantation: a case report.

Background: Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is an extremely rare hematopoietic malignancy, which originating from precursors of plasmacytoid dendritic cells. Allogeneic hematopoietic stem cell transplantation (HSCT) is normally considered in the treatment of BPDCN patients to acquire sustained remission. Post-transplant lymphoproliferative disorder (PTLD) is a group of conditions involving abnormal lymphoid cells proliferation in the context of extrinsic immunosuppression after solid organ transplantation (SOT) or HSCT. Herein, we report a patient with BPDCN, who suffered from PTLD after allogeneic HSCT. Case presentation: A 66-year-old man was diagnosed with BPDCN, confirmed by pathologic examination after splenectomy. The post-surgery 18F-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (18F-FDG PET/CT) showed multifocal 18F-FDG avidity in the left cheek, lymph nodes and bone marrow. The patient started chemotherapy, followed by allogeneic HSCT and immunosuppressive therapy. Four months after the HSCT, the patient developed intermittent fever and recurrent lymphadenopathy, accompanied with progressively elevated Epstein-Barr virus (EBV)-DNA both in serum and lymphocytes. 18F-FDG PET/CT was performed again and found multiple new enlarged 18F-FDG-avid lymph nodes, while the previous hypermetabolic lesions all disappeared. The pathology of mesenteric lymph node indicated a monomorphic PTLD (diffuse large B-cell lymphoma). Then the immunosuppressive medications were stopped and two cycles of Rituximab were given, and the follow-up CT scan indicated a complete response. Conclusion: When patients with BPDCN recurred new enlarged lymph nodes after allogeneic HSCT and immunosuppressive therapy, PTLD should be taken into consideration. 18F-FDG PET/CT may provide additional evidence for supporting or refuting the suspicion of PTLD, and suggest lesions accessible for biopsy.

Generalized Muscular Uptake of 99m Tc-MDP on Bone Scan in a Patient With Scleromyxedema-Associated Myopathy.

ABSTRACT: A 62-year-old man presented with a 5-year history of progressive myasthenia, myalgia, and skin changes. Upon laboratory testing, elevated serum creatine kinase and lactate dehydrogenase, as well as monoclonal immunoglobulin Gκ, were observed. A bone scan revealed generalized muscular uptake of 99m Tc-MDP, whereas 18 F-FDG PET/CT demonstrated only mild hypermetabolism of the muscles. A muscle biopsy showed myofibrillary vacuolar degeneration, and a skin biopsy indicated scleromyxedema. Based on these findings, the patient was diagnosed with scleromyxedema-associated myopathy.

Evaluation of Anlotinib Combined with Adriamycin and Ifosfamide as Conversion Therapy for Unresectable Soft Tissue Sarcomas.

(1) Background: This study investigated the safety and efficiency of adriamycin and ifosfamide combined with anlotinib (AI/AN) as a neoadjuvant conversion therapy in uSTS. (2) Methods: Patients with uSTS were eligible to receive AI/An, including adriamycin (20 mg/m2/d) and ifosfamide (3 g/m2/d) for the first to the third day combined with anlotinib (12 mg/d) for 2 weeks on/1 week off, all of which combine to comprise one cycle. Surgery was recommended after four cycles of treatment. (3) Results: A total of 28 patients were enrolled from June 2018 to December 2020. The best tumor responses included eight patients with partial responses and 20 with a stable disease. Patients with synovial sarcoma and liposarcoma had a significant decrease in the number of tumors compared with fibrosarcoma (p = 0.012; p = 0.042). The overall response rate and disease control rate were 28.57% and 100%, respectively. In total, 24 patients received surgery, while the rates of limb salvage and R0 resection were 91.67% (n = 22/24) and 87.50% (n = 21/24), respectively. Until the last follow-up visit, the mean PFS and RFS were 21.70 and 23.97 months, respectively. During drug administration, 67.87% of patients had grade ≥3 AEs. No treatment-related death occurred. (4) Conclusions: AI/AN followed by surgery showed favorable efficiency and manageable safety in patients with uSTS. A randomized controlled study with a large cohort should be performed for further investigations.

18F-FDG PET/CT in a Patient With Matrix-Producing Carcinoma of the Breast.

ABSTRACT: A 47-year-old woman presented with a large mass in the upper inner quadrant of the left breast. 18F-FDG PET/CT revealed a low-density left breast mass with heterogeneous ring-like 18F-FDG uptake. Core needle biopsy of the tumor revealed a rare subtype of metaplastic breast carcinoma, matrix-producing carcinoma. The tumor size slightly decreased after 6 cycles of neoadjuvant chemotherapy with docetaxel and epirubicin. The left breast was entirely resected subsequently, and the matrix-producing carcinoma of the breast was ultimately diagnosed.

Prognostic significance of pretreatment 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) in patients with primary T cell lymphomas.

OBJECTIVE: T cell lymphomas are associated with an aggressive worse prognosis. This study is designed to assess T cell lymphomas using 18F-FDG PET/CT. METHODS: Sixty-four patients with newly diagnosed T cell lymphomas underwent PET/computed tomography (PET/CT) scans, 47 cases who were fully followed up were retrospectively reviewed and analyzed. Overall survival (OS) and progression-free survival (PFS) were recorded for prognosis. We measured the maximum standardized uptake value (SUVmax) in all cases, analyzed the correlation between SUVmax and survival and other clinicopathologic parameters. Kaplan-Meier log-rank tests were then used to compare the survival of high and low PET/CT parameter groups, and multivariate Cox proportional hazards regression analysis was carried out to identify predictors of OS and PFS. RESULTS: With a median follow-up of 26.5 (range 0.7-117.5) months, the 1-, 2- and 3-year OS were 75.6, 61.7 and 49.2%, and PFS were 49.3, 39.9 and 29.9%, respectively in 47 patients. Among them, 33 cases progressed with a median time of 9.5 (0.7-115.0) months, and 26 patients died with a median survival time of 26.5 (0.7-117.5) months. Multivariate analysis showed the following independent prognostic factors for OS: age >60 years (P = 0.002), SUVmax >9.7 (P = 0.009) and extranodal involvement of more than one site (P = 0.018). In addition, lactate dehydrogenase level (P = 0.003) and B symptoms (P = 0.018) were independent risk factors for PFS. CONCLUSION: Pretherapy SUVmax may serve as an independent predictor of outcome in patients with newly diagnosed T cell lymphomas.

2-[18F]FDG PET/CT parameters associated with WHO/ISUP grade in clear cell renal cell carcinoma.

PURPOSE: To explore the potential parameters from preoperative 2-[18F]FDG PET/CT that might associate with the World Health Organization/the International Society of Urological Pathology (WHO/ISUP) grade in clear cell renal cell carcinoma (ccRCC). METHODS: One hundred twenty-five patients with newly diagnosed ccRCC who underwent 2-[18F]FDG PET/CT prior to surgery or biopsy were retrospectively reviewed. The metabolic parameters and imaging features obtained from 2-[18F]FDG PET/CT examinations were analyzed in combination with clinical characteristics. Univariate and multivariate logistic regression analyses were performed to identify the predictive factors of WHO/ISUP grade. RESULTS: Metabolic parameters of primary tumor maximum standardized uptake value (SUVmax), tumor-to-liver SUV ratio (TLR), and tumor-to-kidney SUV ratio (TKR) were significantly different between any two of the four different WHO/ISUP grades, except those between the WHO/ISUP grade 3 and grade 4. The optimal cutoff values to predict high WHO/ISUP grade for SUVmax, TLR, and TKR were 4.15, 1.63, and 1.59, respectively. TLR (AUC: 0.841) was superior to TKR (AUC: 0.810) in distinguishing high and low WHO/ISUP grades (P = 0.0042). In univariate analysis, SUVmax, TLR, TKR, primary tumor size, tumor thrombus, distant metastases, and clinical symptoms could discriminate between the high and low WHO/ISUP grades (P < 0.05). In multivariate analysis, TLR (P < 0.001; OR: 1.732; 95%CI: 1.289-2.328) and tumor thrombus (P < 0.001; OR: 6.199; 95%CI: 2.499-15.375) were significant factors for differentiating WHO/ISUP grades. CONCLUSION: Elevated TLR (> 1.63) and presence of tumor thrombus from preoperative 2-[18F]FDG PET/CT can distinguish high WHO/ISUP grade ccRCC effectively. 2-[18F]FDG PET/CT may be a feasible method for noninvasive assessment of WHO/ISUP grade.

18F-FDG PET/CT Findings in a Patient With Neurosarcoidosis.

A 58-year-old woman experienced 4 months of headache, fatigue, and depression, as well as 1 week of confusion and hallucinations. F-FDG PET/CT showed numerous hypermetabolic lesions in the pituitary gland and stalk, dura mater, glossopharyngeal nerve, and cauda equina, as well as in cervical and mediastinal lymph nodes. Surgical biopsy of the mediastinal lymph node confirmed the diagnosis of sarcoidosis. The follow-up F-FDG PET/CT, performed at the eighth month after the treatment of glucocorticoids and immunosuppressive agents, demonstrated complete remission of the previous hypermetabolic lesions.

18F-FDG PET/CT in Follicular Dendritic Cell Sarcoma With Paraneoplastic Pemphigus as the First Manifestation.

A 48-year-old woman presented with refractory oral ulcers and skin rashes on the palms and trunk, diagnosed as paraneoplastic pemphigus. The chest x-ray revealed a mass in the right lower chest, and the F-FDG PET/CT scan showed the lesion in the right anterior-inferior mediastinum with intense F-FDG uptake, accompanied by right parasternal adenopathy and pleural effusion. The surgical pathology proved a follicular dendritic cell sarcoma, with right parasternal lymph node metastasis.

18F-FDG PET/CT in a Patient With Thymoma-Associated Paraneoplastic Polymyositis.

A 43-year-old woman presented with progressive muscle weakness and myalgia for 1 month. Laboratory tests revealed the elevation of myogenic enzymes. MRI of the thighs demonstrated a pattern of edema for inflammatory myopathy. Electromyography showed diffuse myopathic disorder, and muscle biopsy indicated polymyositis. F-FDG PET/CT was performed to investigate the potential paraneoplastic syndrome and revealed a soft tissue lesion with F-FDG avidity in the right anterior mediastinum, as well as diffusely increased activity throughout the body muscles. The patient's symptoms and biochemical abnormalities were gradually relieved after the tumor resection, and the histopathology indicated a type AB thymoma.

Bilateral Adrenal Extremely Intense Metabolic Activity on 18F-FDG PET/CT in a Patient With Pheochromocytomas.

Bilateral adrenal masses were found by ultrasound on a 55-year-old man with sudden onset of chest distress and palpitation after drinking alcohol. After the negative laboratory tests of plasma catecholamine and urinary vanillylmandelic acid, the F-FDG PET/CT revealed extremely intense metabolic activity in the bilateral adrenal lesions, and the subsequent I-meta-iodobenzylguanidine scintigraphy also showed increased radioactivity in the lesions. The pathology of surgery confirmed the diagnosis of bilateral pheochromocytomas.

Cholesterol Granuloma Masquerading as Gallbladder Carcinoma on 18F-FDG PET/CT.

F-FDG PET/CT was performed on a 70-year-old man to stage the newly diagnosed multiple myeloma. A hypermetabolic lesion in the gallbladder fundus was revealed incidentally and suspected for gallbladder carcinoma, but was finally proven to be a cholesterol granuloma by the pathology of cholecystectomy.

Diagnosis of Primary Clear Cell Carcinoma of the Vagina by 18F-FDG PET/CT.

A 41-year-old woman presented with irregular vaginal bleeding, and a vaginal tumor was found and proved to be a clear cell carcinoma by biopsy. An F-FDG PET/CT was performed to exclude its metastatic possibility, which showed the vaginal tumor was the only lesion with F-FDG avidity. The vaginectomy and hysterectomy were performed to resect the lesion, and primary clear cell carcinoma of the vagina was finally diagnosed.

Skeletal Superscan on 18F-FDG PET/CT in a Patient With Multiple Myeloma.

An F-FDG PET/CT was performed on a 47-year-old man diagnosed as multiple myeloma with diffuse bone marrow infiltration on pathology. PET/CT findings presented as a pattern of skeletal "superscan," including diffuse and prominent hypermetabolism throughout the axial and proximal appendicular skeleton, which all alleviated after 5 cycles of chemotherapy.

Occult Giant Cell Arteritis Concurrent With Pancreatic Carcinoma Revealed by 18F-FDG PET/CT.

An F-FDG PET/CT was performed on a 74-year-old woman with pancreatic carcinoma and liver metastases. Occult giant cell arteritis, involving the aorta, truncus brachiocephalicus, subclavian arteries, axillaries, external carotid arteries, vertebral arteries, and superficial temporal arteries, was accidentally revealed.