Application of 18F-FDG PET/CT imaging in a primary angiomatoid fibrous histiocytoma of pulmonary bronchus: case report and literature review.

Background: Angiomatoid fibrous histiocytoma (AFH) is a clinically rare, low-grade malignant soft tissue tumor that occasionally metastasizes. It accounts for 0.3% of all soft tissue tumors and most frequently occurs in the extremities, followed by the trunk, and the head and neck. Primary angiomatoid fibrous histiocytoma (PAFH) of the pulmonary bronchus is rare. In this paper, the clinical and imaging data of a case of PAFH of the pulmonary bronchus are reported, and the literature is reviewed. Case description: A 57-year-old female patient presented with a six-month history of cough without apparent cause, characterized by paroxysmal dry cough, chest tightness, and shortness of breath, which worsened with activity. She did not experience fever, chills, chest pain, hemoptysis, or night sweats. Laboratory tests revealed an elevated C-reactive protein and ferritin levels, while tumor markers such as AFP, CEA, CA199, CA125, CA50, and T-SPOT were negative. A chest CT scan showed bronchial obstruction, atelectasis, and a soft tissue density in the right middle lobe of the lung. The enhanced scan demonstrated uneven enhancement of endobronchial nodules. An 18F-FDG PET/CT scan revealed a nodular soft tissue density shadow in the right lung bronchus with uneven density, clear boundaries, and increased 18F-FDG uptake, with a maximum standard uptake value (SUVmax) of 11.2. Bronchoscopy revealed a nodular or polypoid mass that was yellow and tough. Based on imaging findings, the preoperative diagnosis favored lung cancer. However, the postoperative pathological diagnosis confirmed primary angiomatoid fibrous histiocytoma (PAFH) of the pulmonary bronchus. Conclusion: The incidence of primary angiomatoid fibrous histiocytoma (PAFH) is very low, and its clinical manifestations and imaging findings lack specificity, with the final diagnosis relying on pathology. PET/CT imaging has a certain value in the diagnosis of PAFH and holds significant application value in preoperative staging, postoperative efficacy evaluation, and follow-up monitoring. In conclusion, this case report further expands the spectrum of lung and bronchial tumors.

Case report: A rare case of isolated sigmoid Rosai-Dorfman disease on contrast-enhanced CT and 18F-FDG PET/CT.

Rosai-Dorfman disease (RDD) is an uncommon histiocytic disorder that occurs in nodal and/or extranodal sites. Extranodal RDD exhibits a wide range of clinical and radiological presentations, frequently leading to misdiagnoses. Involvement of the gastrointestinal (GI) system is uncommon, accounting for less than 1% of the reported cases. Here we present a case of a 54-year-old male who complained of abdominal distention and was diagnosed with RDD affecting the sigmoid colon, manifesting as a sigmoid mass. The patient had a past medical history of liver transplantation due to hepatocellular carcinoma (HC). This report details the multiphase contrast-enhanced computed tomography (CT) and fluorodeoxyglucose (18F-FDG) positron emission tomography (PET-CT) imaging findings of RDD involving the sigmoid colon without lymphadenopathy, and a review of the relevant literature is provided.

Application value of 18F-FDG PET/CT in primary spleen angiosarcoma with liver metastasis: a case report and literature review.

Background: Primary splenic angiosarcoma (PSA) is a rare neoplasm. It is a malignant tumor derived from endothelial cells of the splenic sinuses. PSA has an unknown etiology, a high degree of malignancy, easy early metastasis, atypical clinical symptoms and imaging findings, and difficult early diagnosis. This paper reports the 18F-FDG PET/CT findings of a case of PSA with intrahepatic metastasis; summarizes its clinical, imaging, and pathological data; and reviews the literature. Case description: A 64-year-old male patient presented with left lower abdominal distending pain without obvious causes on 13 March 2022. The pain was persistent and dull and worsened after sitting and eating. Blood routine examination results were RBC ↓ 3.33 × 1012/L, WBC ↑ 12.32 × 109/L, and PLT ↓ 40 × 109/L. The tumor markers indicated CA125 ↑ 47.0 U/ml, AFP (-), CEA (-), CA199 (-), and CA724 (-). Non-contrast-enhanced CT scan of the abdomen showed that the spleen was significantly enlarged in volume and irregular in shape and had multiple nodules and clumpy low-density shadows, unclear boundaries, uneven density, and multiple necrotic areas. Enhanced CT showed diffuse uneven mild enhancement of the spleen, and the degree of enhancement increased with time. Multiple nodular low-density shadows were seen in the liver, which were slightly enhanced by the enhanced scan.18F-FDG PET/CT showed multiple nodular and massive lesions in the spleen with multiple necrotic areas. There were multiple nodular lesions in the liver, the level of FDG metabolism increased, the SUVmax of the spleen lesions was 9.0, and the SUVmax of the liver lesions was 5.6. The 18F-FDG PET/CT diagnosis was splenic malignancy with liver metastasis. Finally, after a multidisciplinary discussion, it was decided to perform laparoscopic total splenectomy and portal vein infusion chemotherapy. Pathological examination showed that the tumor cells were round, oval, or fusiform, with obvious atypia, arranged into a cable or anastomosed vascular lumen. The final diagnosis was primary splenic angiosarcoma with massive necrosis. After surgery, the patient received antitumor combined therapy and died 5 months later. Conclusion: The incidence of PSA is very low, and its clinical and radiological manifestations lack specificity. 18F-FDG PET/CT imaging has a certain diagnostic value for PSA and significant utility in preoperative staging, guiding biopsy procedures, evaluating postoperative treatment response, and monitoring disease recurrence. PSA should be considered in the presence of a space-occupying lesion within the spleen that exhibits necrotic areas, shows progressive enhancement on contrast-enhanced scans, and demonstrates heterogeneous increases in FDG uptake.

Inferring the diagnostic potential of 18F-FDG-PET/CT in post-renal transplantation from a unique case harboring multiple rare complications.

Renal transplantation is undoubtedly an effective treatment for patients with end-stage renal disease, but it is certainly not a cure. Patients require lifelong immunosuppression to maintain optimal allograft function, and post-operative risk complications such as cancer in the transplant recipient cannot be ignored. Besides, infection is a silent complication that follows transplantation. Relatedly, herein, we present a report of a 40-year-old patient who underwent renal transplantation and promptly developed a diffuse large B-cell tumor in the liver and Aspergillus infection in the trachea. In addition, an inflammatory necrotizing granuloma was also observed in the muscles. Of importance, we also described the potential of 18F-FDG-PET/CT, which was instrumental in monitoring and evaluating these relevant post-operative complications in this rare case.

Primary unifocal thymic Rosai-Dorfman disease: an extremely rare challenge in diagnostic practice.

Rosai-Dorfman disease (RDD) is currently considered a group of neoplastic diseases of unknown etiology, with monoclonal proliferation of histiocytes, showing unique histopathologic features and varying clinical presentation. Primary thymic RDD is an extremely rare extranodal form of this disorder. In this study, we describe the case of an otherwise healthy 64-year-old Chinese man who presented with an isolated, asymptomatic soft tissue density lesion in the anterior mediastinum detected by computed tomography. Histology of the surgical specimen revealed infiltration of thymic tissue by sheets of large histiocytes with mixed lymphocytes and plasma cells, and background fibrosis. Immunohistochemical staining of the histiocytes was positive for S100, CD68, CD163, OCT2 and cyclin D1, but negative for CD1a and BrafV600E expression, thus supporting a diagnosis of RDD. Primary thymic RDD is extremely rare and may be a diagnostic challenge when presenting as mediastinal lesion.

A rare imaging presentation with multisystemic clinicopathological features of Langerhans cell histiocytosis: Case report and literature review.

RATIONALE: Langerhans cell histiocytosis (LCH) is a kind of rare disease in which dendritic cells proliferate abnormally. It often occurs in children and can involve any tissue and organ. The affected sites usually include bone, skin, pituitary gland, and lungs, while the thyroid gland and external auditory canal are rarely observed. The perineal and labial involvement of this disease has not been reported yet. PATIENT CONCERNS: A 47-year-old female patient experienced a swelling of the anterior neck area without an obvious inducement. She noticed a quail egg-like mass on the left side, and the mass increased progressively within 3 months. The anterior neck area was found to be swollen, and some flaky red rashes were seen on the scalp and bilateral external auditory canals. DIAGNOSES: Imaging examination showed enlarged thyroid and cervical lymph nodes, multiple low-density nodules in the liver, and reduced signal in the posterior pituitary gland. The biopsy pathological result of the increased left cervical lymph node indicated that LCH was detected. INTERVENTIONS: VP regimen (vincristine, dexamethasone per os) and related supportive treatments were given as inducing chemotherapy for 6 weeks. OUTCOMES: After the second chemotherapy, the rash on the scalp and external auditory canal improved, and the neck mass was significantly reduced. After the third chemotherapy, the rash was mostly disappeared, while the neck lumps increased during chemotherapy. Thus, clatribine chemotherapy was recommended as the follow-up. LESSONS: Imaging examinations played an important role in the diagnosis and follow-up of the disease, especially 18F-FDG PET/CT, which could show multiple involving organs at the same time. When a patient suffering from diabetes insipidus, skin rash, or fever, has a high FDG uptake PET/CT result in multiple tissues and organs throughout the body, it is necessary to consider the possibility of LCH.

Application of 18F-FDG PET/CT imaging in gallbladder inflammatory pseudotumor with elevated CA199: a case report and review of literature.

Background: Gallbladder inflammatory pseudotumor (GIPT) is a nonspecific chronic proliferative inflammation of the gallbladder. At present, the pathogenesis is not clear, which may be related to bacterial and viral infections, congenital diseases, gallstones, chronic cholangitis and so on. GIPT is rare and the imaging examination has no obvious specificity. There are few reports on the 18F-FDG PET/CT imaging characteristics of GIPT. In this paper, 18F-FDG PET/CT findings of GIPT with elevated CA199 are reported and the literature is reviewed. Case description: A 69-year-old female patient presented with recurrent intermittent right upper abdominal pain for more than 1 year, followed by nausea and vomiting for 3 hours, without fever, dizziness, chest tightness and other symptoms. Complete CT, MRI, PET/CT and related laboratory tests, CEA (-), AFP (-), Ca199 224.50U/mL ↑,18F-FDG PET/CT images showed uneven thickening at the bottom of the gallbladder, slightly increased gallbladder volume, eccentric and localized thickening of the gallbladder body wall, nodular soft tissue density shadow, clear boundary, smooth gallbladder wall, presence and smooth hepatobiliary interface, increased FDG radioactivity uptake, SUVmax was 10.2.The tumor was resected after operation and was diagnosed as gallbladder inflammatory pseudotumor by postoperative pathology. Conclusion: 18F-FDGPET/CT imaging has a certain significance for gallbladder inflammatory pseudotumor. In patients with chronic cholecystitis, when the CA199 increases, the gallbladder wall appears localized thickening, the hepatobiliary interface exists and is smooth, and the 18F-FDG metabolism is mildly to moderately increase. Gallbladder cancer cannot be diagnosed alone, and the possibility of gallbladder inflammatory pseudotumor should also be considered. However, it should be noted that the cases with unclear diagnosis should still be actively treated with surgery, so as not to delay the treatment opportunity.

Development and validation of a MRI-based combined radiomics nomogram for differentiation in chondrosarcoma.

Objective: This study aims to develop and validate the performance of an unenhanced magnetic resonance imaging (MRI)-based combined radiomics nomogram for discrimination between low-grade and high-grade in chondrosarcoma. Methods: A total of 102 patients with 44 in low-grade and 58 in high-grade chondrosarcoma were enrolled and divided into training set (n=72) and validation set (n=30) with a 7:3 ratio in this retrospective study. The demographics and unenhanced MRI imaging characteristics of the patients were evaluated to develop a clinic-radiological factors model. Radiomics features were extracted from T1-weighted (T1WI) images to construct radiomics signature and calculate radiomics score (Rad-score). According to multivariate logistic regression analysis, a combined radiomics nomogram based on MRI was constructed by integrating radiomics signature and independent clinic-radiological features. The performance of the combined radiomics nomogram was evaluated in terms of calibration, discrimination, and clinical usefulness. Results: Using multivariate logistic regression analysis, only one clinic-radiological feature (marrow edema OR=0.29, 95% CI=0.11-0.76, P=0.012) was found to be independent predictors of differentiation in chondrosarcoma. Combined with the above clinic-radiological predictor and the radiomics signature constructed by LASSO [least absolute shrinkage and selection operator], a combined radiomics nomogram based on MRI was constructed, and its predictive performance was better than that of clinic-radiological factors model and radiomics signature, with the AUC [area under the curve] of the training set and the validation set were 0.78 (95%CI =0.67-0.89) and 0.77 (95%CI =0.59-0.94), respectively. DCA [decision curve analysis] showed that combined radiomics nomogram has potential clinical application value. Conclusion: The MRI-based combined radiomics nomogram is a noninvasive preoperative prediction tool that combines clinic-radiological feature and radiomics signature and shows good predictive effect in distinguishing low-grade and high-grade bone chondrosarcoma, which may help clinicians to make accurate treatment plans.

Application value of PET/CT in monophasic primary sacral synovial sarcoma: a case report and review of literature.

Background: Synovial sarcoma is a malignant tumor of mesenchymal origin with a high degree of malignancy and easy metastasis. It mostly occurs in distal extremities or adjacent joints, and it is most common in deep knee joint. Primary sacral synovial sarcoma (PSSS) is extremely rare. The PET/CT imaging findings of a case of monophasic PSSS were reported. The clinical, imaging, and pathological data were summarized, and the literature was reviewed. Case description: A 67-year-old female patient presented with sacrococcygeal pain without obvious causes on 16 September 2022, with occasional pain at night, as well as aggravated pain during hip flexion and long-distance walking, which could be slightly relieved with rest, without special treatment. For further treatment before 1 month to Jiangxi Provincial People's Hospital, after admission, laboratory tests were negative. Non-contrast CT scan showed expansive bone destruction in the S1-3 vertebrae with soft tissue density of about 58 mm × 46 mm × 52 mm. The boundary was clear, necrosis was visible within the vertebrae, and the boundary between the mass and the anterior sacral blood vessels and rectum was unclear. Non-contrast MRI scan showed mixed signals in lumbosacral masses, with equal signals in T1 and uneven and slightly higher signals in T2. Cystic degeneration and necrosis were visible, with multiple compartments in the lumbosacral masses. MRI enhancement showed uneven enhancement of lumbosacral mass with multiple compartments and no enhanced cystic lesion. The left sacral alar bone is destroyed, as shown by large flaky uneven strengthening. PET/CT showed that S1-3 vertebral body and left sacral alar bone were destroyed and soft tissue shadow formed, invading the sacral canal and the left foramina of S1-3. FDG metabolism was significantly increased, and malignant tumor was diagnosed by PET/CT. Pathological examination: The pathological diagnosis was monophasic PSSS. After systemic chemotherapy and local radiotherapy, no significant signs of recurrence and metastasis were found on CT so far. Follow-up treatment was continued. Conclusion: The incidence of PSSS is very low, its clinical and imaging manifestations lack characteristics, and the final diagnosis still needs pathology. PET/CT imaging has a certain value in the diagnosis of PSSS and has great application value in the preoperative staging, postoperative efficacy evaluation, and follow-up.

Role of 18F-FDG PET/CT in patients affected by pulmonary primary lymphoma.

Background: Primary pulmonary lymphoma (PPL) is defined as clonal abnormal hyperplasia of lung parenchyma or bronchial lymphoid tissue originating from bronchial mucosal tissue. However, PPL is rare, which accounts for approximately 3-4% of extraneurotic lymphomas and 0.5-1% of all primary tumors in the lung. Owing to the lack of any typical clinical symptoms and radiological features, it is challenging to accurately diagnose PPL, which affects its clinical management and prognosis. Considering this, herein, we aim to raise awareness of this disease and help physicians understand the role of 18F-FDG PET/CT in the diagnosis of PPL. Method: A retrospective analysis was performed on the clinical and 18F-FDG PET/CT imaging data of 19 patients diagnosed with PPL by biopsy pathology at our hospital from April 2014 to December 2021. Results: Of the 19 PPL patients, 15 patients showed clinical symptoms with the most common being fever and cough. In addition, there were 4 cases that had no clinical symptoms, and all of them were MALT lymphoma. In fact, 16 patients were misdiagnosed as lobar pneumonia, lung cancer, tuberculosis, and diffuse interstitial inflammation, representing a misdiagnosis rate of 84.2%. Also, 73.7% were MALT lymphomas, representing the most common pathological pattern, along with 3 DLBCL and 2 T-cell lymphomas. With reguard to CT signs, the air-bronchial sign was found to be the most common, followed by the halo sign and the collapsed leaf sign. On the basis of the predominant radiologic features, lesions were categorized as pneumonic consolidation, nodular/mass type, diffuse interstitial type, and mixed type. The average SUVmax of lesions was 7.23 ± 4.75, the ratio of SUVmax (lesion/liver) was 3.46 ± 2.25, and the ratio of SUVmax (lesion/mediastinal blood pool) was found to be 5.25 ± 3.27. Of interest, the different pathological types of PPL showed different values of 18F-FDG uptake. The 18F-FDG uptake of DLCBL was the most prominent with a SUVmax of 15.33 ± 6.30 and was higher than that of MALT lymphoma with a SUVmax of 5.74 ± 2.65. There appeared similarity in 18F-FDG uptake between MALT lymphoma and T-cell lymphoma. For the SUVmax of lesion, we found statistical significance between MALT lymphoma and DLCBL (P value<0.001). In addition, we also found statistical significance (P value < 0.05) in SUVmax of lesions between pneumonic consolidation type and nodal/mass type, I stage, and other stages. Conclusions: On 18F-FDG PET/CT images, certain features of PPL morphology and metabolism can be identified that may contribute to a better understanding of this disease. In addition, 18F-FDG PET/CT whole-body imaging has the potential to refine the staging of PPL. Most importantly, functional 18F-FDG PET/CT imaging can readily reflect tumor cell activity, thus allowing for the selection of an optimal biopsy site.

Application of 18F-FDG PET/CT in Langerhans Cell Histiocytosis.

Purpose: This study aims to explore the application value of the 18F-FDG PET/CT imaging in diagnosing, staging, and typing Langerhans cell histiocytosis (LCH) via the morphological and metabolic analyses of the 18F-FDG PET/CT images. Methods: We retrospectively analyzed the 18F-FDG PET/CT images and clinical data of nineteen patients with LCH. The shape, size, density, distribution, and 18F-FDG uptake of all lesions were documented. In addition, the SUVmax of the lesions, liver, and blood pool was measured prior to calculating the lesion-to-liver and lesion-to-blood pool ratios. Results: Among the 19 analyzed patients, the positive rate of the PET/CT image was 94.7% (18/19), with 1 false negative (5.3%, 1/19) case occurring in the cutaneous LCH. Among the 76 lesions, 69 were FDG-avid lesions (69/76, 90.8%). Additionally, we observed no FDG uptake in 7 lesions (7/76, 9.2%). In contrast, 59 lesions (59/76, 77.6%) were abnormal on diagnostic CT scan, but 17 lesions (17/76, 22.4%) were undetected. The 18F-FDG PET/CT image revealed additional 6 lesions in the bone, 4 in the lymph node, 3 in the spleen, and 3 occult lesions, which CT scan did not detect. Additionally, there were 6 cases with single-system LCH. The remaining 13 cases were multisystem LCH. Our 18F-FDG PET/CT image analyses altered the typing of 4 LCH patients. In the case of all lesions, the mean SUVmax of the 18F-FDG-avid lesions was 5.4 ± 5.1 (range, 0.8∼26.2), and the mean lesion-to-liver SUVmax ratio was 3.1 ± 2.52 (range, 0.7∼11.9), and the mean lesion-to-blood pool SUVmax ratio was 4.6 ± 3.4 (range 0.7∼17.5). Conclusion: The 18F-FDG PET/CT image plays an essential role in LCH diagnosis, primary staging, and typing. It can accurately evaluate the distribution, range, and metabolic information of LCH, providing a vital imaging basis for the clinical evaluation of disease conditions, selection of treatment schemes, and determining patient prognosis.

Role of 18F-FDG PET/CT in the diagnosis and management of patients with Langerhans cell histiocytosis.

Background: Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasm that can involve multisystem organs. Positron emission tomography/computed tomography (PET/CT) has been widely used in tumor staging and efficacy evaluation. However, at present, there are few 18F-fluorodeoxyglucose (FDG) PET/CT studies on LCH. This study aimed to explore the possible role of 18F-FDG PET/CT in the diagnosis and management of patients with LCH. Methods: 18F-FDG PET/CT images of 22 Chinese patients diagnosed with LCH on biopsy or surgery histopathology between January 2011 and December 2020 were retrospectively analyzed. The incidence of LCH in each system was assessed by a PET/CT scan. The imaging characteristics were analyzed semiquantitatively and qualitatively. The discrepancies between PET/CT and conventional imaging modalities were recorded. Evaluations of curative effect according to RECIST1.1 and PERCIST1.0 were compared using Fisher's exact chi-squared test, and P values <0.05 were considered significant. Results: Eight (36.4%) of the 22 patients presented with single system involvement (4 isolated site involvement, 4 multiple site involvement), and 14 (63.6%) presented with multiple system involvement. Twenty-one (95.5%) patients had hypermetabolic lesions. Musculoskeletal, lymphatic, respiratory, liver, skin-soft tissue and thyroid involvement were seen in 14 (63.6%), 13 (59.1%), 5 (22.7%), 4 (18.2%), 5 (22.7%) and 1 (4.5%) patient, respectively. Cranial and facial bones were the most common sites of musculoskeletal involvement. Ten patients underwent PET/CT follow-up, and there was no significant difference in curative effect evaluations according to RECIST1.1 and PERCIST1.0. However, among the complete remission cases assessed by RECIST1.1, three were partial metabolic responses assessed by PERCIST1.0, while among the partial response cases assessed by RECIST1.1, one was metabolic progressive disease assessed by PERCIST1.0. Conclusions: 18F-FDG PET/CT is an imaging modality option for the diagnosis and assessment of the curative effect of LCH.

Analysis of misdiagnosis and 18F-FDG PET/CT findings of lymph node tuberculosis.

OBJECTIVE: To investigate 18F-FDG PET/CT findings of tuberculous lymphadenitis and analyze the causes of misdiagnosis. METHOD: Between 2013 and 2021, a retrospective review was conducted on 22 patients at Jiangxi Provincial People's Hospital Affiliated with Nanchang University who had lymph node tuberculosis confirmed by histology or clinical investigation. Subjective judgment and quantitative analysis were adopted. RESULTS: Out of 22 patients, 14 are male and 8 are female. The average age was 55.5 years (55.5±12.4). The most common site of lymph node tuberculosis (LNTB) is the mediastinum (41.5%), followed by the neck (24.4%) and the abdominal cavity (21.9%). Half of the patients have more than one site affected. More than half of LNTB patients (54.5%) are concurrent with other types of TB, especially PTB. Among the 41 biggest affected lymph nodes, the average maximum diameter, minimum diameter, SUVmax and the lesion SUVmax/SUVmean liver ratio are 22.04±8.39, 16.93±6.75, 9.72±5.04 and 6.72±3.60, respectively. There is a poor correlation coefficient of 0.236 between the FDG uptake and the size of the biggest affected lymph node. Patients who are concurrent with no other TB have the significantly higher FDG uptake than patients who are concurrent with other TB (12.42 vs 8.02) (p = 0.005). Among these cases, 6 cases (27.3%) are accurately diagnosed with LNTB, all of which have pulmonary tuberculosis as a complication. However, 16 cases (72.7%) are misdiagnosed as lymphoma (50%), sarcoidosis (13.6%), and lymph node metastasis (9%). CONCLUSIONS: This study demonstrates that 18F-FDG PET/CT is very useful in detecting LNTB because tuberculous granulomas show significant levels of glucose uptake. It proves to be an effective method for revealing lesion extent and discovering additional lesions that morphological imaging is missed. However, 18F-FDG PET/CT is not able to reliably distinguish LNTB from lymphoma, sarcoidosis, and metastatic lymph nodes. Nonetheless, 18F-FDG PET/CT allows for the selection of the most optimal biopsy location, and thus has potential to detect early treatment response and distinguish between active and inactive lesions.