[Analysis of imaging features of rare tumors in nasal cavity and paranasal sinus].

Objective:To explore the imaging features of rare tumors of nasal cavity and sinuses, and to improve the understanding of these diseases, thereby aiding clinical diagnosis and treatment. Methods:The CT and MRI findings of 79 cases of rare neoplasm of nasal cavity and sinuses confirmed by pathology were retrospectively analyzed, and the imaging features were summarized. Results:Among the 79 cases, there were 16 cases of neuroendocrine carcinoma, most showing expansive and infiltrative bone destruction without hyperosteogeny and sclerosis. The sphenoid sinus exhibited a "pigeon" shape. In 28 cases of malignant melanoma, MRI signals were diverse, typical signals were rare, but mixed signals were more common. In 12 cases of rhabdomyosarcoma, MRI enhancement mostly showed "grape-like" enhancement and partial ring enhancement; There were 10 cases of olfactory neuroblastoma, the lesions were consistent with the distribution area of olfactory mucosa, most of them were lobulated, marginal nodules, and "flower ring" enhancement, and 2 cases grew across intracranial and external, with multiple cystic lesions and surrounding flaky edema bands. In 5 cases of solitary fibrous tumor, Benign tumors had regular shape and uniform density, while malignant tumors had irregular shape and uneven density, The enhancement was obviously uneven and showed a "pattern" change. There were 2 cases of sarcomatoid carcinoma, both with lobed appearance, uneven density, lamellar low-density shadow, and osteolytic bone destruction. In 4 cases of schwannoma, the enhancement showed obvious inhomogeneous enhancement. One case showed cystic necrosis, one case showed calcification, and the surrounding structure was compressed without damage. There was 1 case of neurofibroma, with many cystic components, low signal separation and compartmentalized enhancement. One case of paraganglioma showed moderate enhancement in the arterial phase and progressive enhancement in the venous phase, accompanied by significant swelling bone destruction. Conclusion:Rare tumors of nasal cavity and paranasal sinuses have distinctive imaging features. CT and MRI can effectively show the extent of the lesions and the degree of infiltration into adjacent tissues and organs, which is helpful for early clinical diagnosis and staging. However, definitive diagnosis still depends on pathology and immunohistochemistry.

The role of [18F]F-DOPA PET/CT in diagnostic and prognostic assessment of medullary thyroid cancer: a 15-year experience with 109 patients.

Objective: Correct diagnosis and prognostic evaluation of medullary thyroid cancer (MTC) are crucial to treat patients. The purpose of this study was to evaluate the diagnostic and prognostic value of [18F]F-DOPA PET/CT in patients with MTC. Methods: We reviewed MTC patients who underwent [18F]F-DOPA PET/CT from June 2008 to November 2023. Clinical characteristics, follow-up data, and the following [18F]F-DOPA PET/CT parameters were recorded: maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), and SUVmean of multiple organs. The diagnostic value of PET/CT for the detection of tumor lesions was calculated. Serum basal calcitonin (bCt) and stimulated calcitonin (sCt) were determined. Receiver operating characteristics, Kaplan-Meier, and Cox regression analyses were performed. Results: In total, 109 patients (50 women, 59 men; average age, 55 ± 14 years) were included in the analysis. The patient-related sensitivity, specificity, and accuracy of [18F]F-DOPA PET/CT were 95%, 93%, and 94%, respectively. The lesion-related sensitivity, specificity, and accuracy were 65%, 99%, and 72%, respectively. The optimal cutoff values of bCt, sCt, and CEA to obtain positive [18F]F-DOPA PET/CT results were 64 pg/mL, 1808 pg/mL, and 4 µg/L, respectively. Patients with negative [18F]F-DOPA PET/CT had longer overall survival than patients with positive [18F]F-DOPA PET/CT results (P = 0.017). Significant positive correlations were found between bCt, sCt, and CEA with SUVmax, SUVmean, and MTV of [18F]F-DOPA PET/CT (P < 0.001). [18F]F-DOPA PET/CT results and MTV may be useful for the evaluation of the prognosis of patients with recurrent MTC, while age and MTV were independent prognostic factors in patients with primary MTC. For all patients, SUVmean of the left kidney, liver, aorta, and pancreas might be used to independently predict OS. Conclusion: [18F]F-DOPA PET/CT had great value for diagnosis and prognostic assessment in patients with MTC. The DOPA PET/CT parameter SUVmean and MTV showed significant association with OS.

[Imaging characteristics and diagnosis of primary middle mediastinal tumors].

Objectives: To investigate the proportion of different histological types and CT enhanced imaging features of primary middle mediastinal lesions in order to improve the understanding of these tumors and the accuracy of preoperative diagnosis. Methods: Retrospective analysis was conducted on 84 patients with primary middle mediastinal lesions and clear histological classifications diagnosed and treated at the Cancer Hospital, Chinese Academy of Medical Sciences from January 2012 to December 2022. Clinical, imaging, and pathological data were collected and classified according to tumor histological classifications. CT imaging manifestations such as tumor location, size, morphology, edge, boundary, internal components, enhancement characteristics, and surrounding tissue invasion were evaluated and recorded. Results: The histological types of the primary middle mediastinal lesions from the 84 patients included mesenchymal tumors, anterior intestinal cysts, giant lymph node hyperplasia, substernal goiter, neuroendocrine carcinoma, lymphohematopoietic system tumors, and mesothelioma, accounting for 28.6%, 27.4%, 14.3%, 3.6%, 11.9%, 9.5%, and 4.8%, respectively. Mesenchymal tumors included peripheral nerve sheath tumors, vascular tumors, adipogenic tumors, solitary fibrous tumors, and synovial sarcoma, accounting for 54.2%, 20.8%, 12.5%, 8.3%, and 4.2%, respectively. The above tumors had diverse imaging manifestations and specific imaging features. Mature fat were found in 3 cases of liposarcoma; Calcification was observed in 2 cases of thyroid nodules and 7 cases of giant lymph node hyperplasia; Enhanced scanning showed significant enhancement in 2 cases of solitary fibrous tumors, 3 cases of thyroid nodules, and 11 cases of giant lymph node hyperplasia; Mediastinal large lymph nodes was observed in 6 cases of lymphoma and 3 cases of mesothelioma; High invasiveness was observed in 4 cases of mesothelioma and 9 cases of neuroendocrine carcinoma. Conclusion: Mediastinal tumors have low incidence rate and rich histological types, and their imaging manifestations are diverse. Preoperative differential diagnosis can be made according to their specific imaging characteristics.

Mixed neuroendocrine-non-neuroendocrine neoplasm of the bile duct with long-term prognosis after neoadjuvant chemotherapy.

A 74-year-old man with obstructive jaundice presented with a thickened distal bile duct wall. A transpapillary forceps biopsy revealed an adenocarcinoma; however, because the tumor image was different from that of a typical cholangiocarcinoma, endoscopic ultrasound-guided fine-needle aspiration was performed on the tumor and enlarged lymph nodes. The tumor cells were positive for synaptophysin and CD56 with a Ki67 labeling index of 95%, and he was diagnosed with small cell neuroendocrine carcinoma. We diagnosed a bile duct tumor with neuroendocrine carcinoma component with lymph node metastasis. Preoperative chemotherapy for neuroendocrine carcinoma was administered because R0 resection was difficult and the risk of postoperative recurrence was high. Three courses of chemotherapy with carboplatin and etoposide resulted in marked tumor shrinkage, and radical resection was performed 3 months after diagnosis. Postoperative pathology revealed adenocarcinoma in the mucosal epithelium and small cell neuroendocrine carcinoma in the submucosa, most of which resolved with chemotherapy. Carboplatin and etoposide were resumed as adjuvant chemotherapy, and 67 months of recurrence-free survival were achieved after surgery.

False-Negative 68 Ga-FAPI PET/CT in Pediatric Thyroid Medullary Carcinoma Seen With 68 Ga-DOTATOC PET/CT and 18 F-FDG PET/CT.

ABSTRACT: In adults, 68 Ga-FAP inhibitor ( 68 Ga-FAPI) PET/CT outperforms 68 Ga-radiolabeled somatostatin analog peptides ( 68 Ga PET/CT) and 18 F-FDG PET/CT in detecting thyroid lesions. This is the case of a 13-year-old boy newly diagnosed with medullary thyroid cancer with high calcitonin level. 68 Ga PET/CT revealed the presence of only a primary thyroid lesion. Proven to be superior in detecting metastasis, 68 Ga-FAPI PET/CT was performed. The results came out negative for primary and potential metastatic lesions. This case sheds shed light on false-negatives reported in 68 Ga-FAPI PET/CT scans in pediatric patients, emphasizing the need for alternate radiotracers when a negative study is met.

The machine learning-based model for lateral lymph node metastasis of thyroid medullary carcinoma improved the prediction ability of occult metastasis.

BACKGROUND: For medullary thyroid carcinoma (MTC) with no positive findings in the lateral neck before surgery, whether prophylactic lateral neck dissection (LND) is needed remains controversial. A better way to predict occult metastasis in the lateral neck is needed. METHODS: From January 2010 to January 2022, patients who were diagnosed with MTC and underwent primary surgery at our hospital were retrospectively reviewed. We collected the patients' baseline characteristics, surgical procedure, and rescored the ultrasound images of the primary lesions using American College of Radiology (ACR) Thyroid Imaging, Reporting and Data System (TI-RADS). Regularized logistic regression, 5-fold cross-validation and decision curve analysis was applied for lateral lymph node metastasis (LLNM) model's development and validation. Then, we tested the predictive ability of the LLNM model for occult LLNM in cN0-1a patients. RESULTS: A total of 218 patients were enrolled. Five baseline characteristics and two TI-RADS features were identified as high-risk factors for LLNM: gender, baseline calcitonin (Ctn), tumor size, multifocality, and central lymph node (CLN) status, as well as TI-RADS margin and level. A LLNM model was developed and showed a good discrimination with 5-fold cross-validation mean area under curve (AUC) = 0.92 ± 0.03 in the test dataset. Among cN0-1a patients, our LLNM model achieved an AUC of 0.91 (95% CI, 0.88-0.94) for predicting occult LLNM, which was significantly higher than the AUCs of baseline Ctn (0.83) and CLN status (0.64). CONCLUSIONS: We developed a LLNM prediction model for MTC using machine learning based on clinical baseline characteristics and TI-RADS. Our model can predict occult LLNM for cN0-1a patients more accurately, then benefit the decision of prophylactic LND.

Incidental 68Ga-DOTATATE uptake in thyroid nodules: Is guideline-directed management still appropriate?

BACKGROUND: Fluorodeoxyglucose uptake on positron emission tomography imaging has been shown to be an independent risk factor for malignancy in thyroid nodules. More recently, a new positron emission tomography radiotracer-Gallium-68 DOTATATE-has gained popularity as a sensitive method to detect neuroendocrine tumors. With greater availability of this imaging, incidental Gallium-68 DOTATATE uptake in the thyroid gland has increased. It is unclear whether current guideline-directed management of thyroid nodules remains appropriate in those that are Gallium-68 DOTATATE avid. METHODS: We retrospectively reviewed Gallium-68 DOTATATE positron emission tomography scans performed at our institution from 2012 to 2022. Patients with incidental focal Gallium-68 DOTATATE uptake in the thyroid gland were included. Fine needle aspiration biopsies were characterized via the Bethesda System for Reporting Thyroid Cytopathology. Bethesda III/IV nodules underwent molecular testing (ThyroSeq v3), and malignancy risk ≥50% was considered positive. RESULTS: In total, 1,176 Gallium-68 DOTATATE PET scans were reviewed across 837 unique patients. Fifty-three (6.3%) patients demonstrated focal Gallium-68 DOTATATE thyroid uptake. Nine patients were imaged for known medullary thyroid cancer. Forty-four patients had incidental radiotracer uptake in the thyroid and were included in our study. Patients included in the study were predominantly female sex (75%), with an average age of 62.9 ± 13.9 years and a maximum standardized uptake value in the thyroid of 7.3 ± 5.3. Frequent indications for imaging included neuroendocrine tumors of the small bowel (n = 17), lung (n = 8), and pancreas (n = 7). Thirty-three patients underwent subsequent thyroid ultrasound. Sonographic findings warranted biopsy in 24 patients, of which 3 were lost to follow-up. Cytopathology and molecular testing results are as follows: 12 Bethesda II (57.1%), 6 Bethesda III/ThyroSeq-negative (28.6%), 1 Bethesda III/ThyroSeq-positive (4.8%), 2 Bethesda V/VI (9.5%). Four nodules were resected, revealing 2 papillary thyroid cancers, 1 neoplasm with papillary-like nuclear features, and 1 follicular adenoma. There was no difference in maximum standardized uptake value between benign and malignant nodules (7.0 ± 4.6 vs 13.1 ± 5.7, P = .106). Overall, the malignancy rate among patients with sonography and appropriate follow-up was 6.7% (2/30). Among patients with cyto- or histopathology, the malignancy rate was 9.5% (2/21). There were no incidental cases of medullary thyroid cancer. CONCLUSION: The malignancy rate among thyroid nodules with incidental Gallium-68 DOTATATE uptake is comparable to rates reported among thyroid nodules in the general population. Guideline-directed management of thyroid nodules remains appropriate in those with incidental Gallium-68 DOTATATE uptake.

CT and MRI findings of small cell neuroendocrine carcinoma of the urinary bladder: comparison with urothelial carcinoma.

OBJECTIVE: This study aimed to evaluate the efficacy of CT and MRI findings to differentiate small cell neuroendocrine carcinoma (SCNEC) from urothelial carcinoma (UC) of the urinary bladder. MATERIALS AND METHODS: This study included 90 patients with histopathologically confirmed bladder cancer (10 SCNECs and 80 UCs). Eight patients with bladder SCNEC and 80 with UC underwent CT and MRI, whereas the remaining two patients with SCNEC underwent CT alone before treatment. CT and MRI findings were retrospectively evaluated and compared between the two pathologies. RESULTS: The maximum diameter (36.5 mm vs. 19.0 mm, p < 0.01) and height (22.0 mm vs. 14.0 mm, p < 0.01) of the tumor in bladder SCNEC were higher than in UC. The pedunculated configuration (20% vs. 61%, p < 0.05) and irregular tumor margins (20% vs. 76%, p < 0.01) in bladder SCNEC were less common than in UC. The CT attenuation of the solid component in unenhanced CT images was higher in bladder SCNEC than in UC (37 Hounsfield unit [HU] vs. 34 HU, p < 0.01). The apparent diffusion coefficient (ADC) of the solid component in bladder SCNEC was lower than in UC (0.49 × 10-3 mm2/s vs. 1.02 × 10-3 mm2/s, p < 0.01). CONCLUSION: In comparison with UC, bladder SCNEC was larger, had higher unenhanced CT attenuation, and had a lower ADC value. The pedunculated configuration and irregular tumor margins were typical of bladder UC.

Correlation of 18F-sodium fluoride uptake and radiodensity in extraosseous metastases of medullary thyroid carcinoma.

Objective: Although 18F-sodium fluoride (18F-NaF) uptake is frequently observed in extraosseous metastases of medullary thyroid carcinoma (MTC) with calcification, itcan also occur in metastatic sites without visible calcium deposition, leading to the hypothesis that visually undetectable calcium accumulation may be responsible for this uptake. The aim of this study was to indirectly support this hypothesis by analyzing the correlation between the degree of 18F-NaF uptake and radiodensity in extraosseous MTC metastases, since calcium deposition can increase attenuation even when not visually detectable. Subjects and methods: Extraosseous metastatic lesions of 15 patients with MTC were evaluated using 18F-NaF positron-emission tomography (PET)/computed tomography (CT)and segmented by levels of standardized uptake value (SUV). The correlation between mean SUV and mean Hounsfield unit (HU) values was assessed for the entire group of segments and for two subgroups with different mean HU values. Results: Very high correlations were observed between mean SUV and mean HU values for both the entire group of segments and the subgroup with a mean HU value greater than 130 (p = 0.92 and p = 0.95, respectively; p < 0.01). High correlation (p = 0.71) was also observed in the subgroup with mean HU values ranging from 20 to 130 (p < 0.01). Conclusion: The findings of the present study suggest that there is an association between 18F-NaF uptake and calcium deposition in extraosseous metastasesof MTC, supporting the hypothesis that visually undetectable calcium accumulation may be responsible for 18F-NaF uptake in regions without visible calcium deposition.

An orthotopic prostate cancer model for new treatment development using syngeneic or patient-derived tumors.

BACKGROUND: There are limited preclinical orthotopic prostate cancer models due to the technical complexity of surgical engraftment and tracking the tumor growth in the mouse prostate gland. Orthotopic xenografts recapitulate the tumor microenvironment, tumor stromal interactions, and clinical behavior to a greater extent than xenografts grown at subcutaneous or intramuscular sites. METHODS: This study describes a novel micro-surgical technique for orthotopically implanting intact tumors pieces from cell line derived (transgenic adenocarcinoma mouse prostate [TRAMP]-C2) or patient derived (neuroendocrine prostate cancer [NEPC]) tumors in the mouse prostate gland and monitoring tumor growth using magnetic resonance (MR) imaging. RESULTS: The TRAMP-C2 tumors grew rapidly to a predetermined endpoint size of 10 mm within 3 weeks, whereas the NEPC tumors grew at a slower rate over 7 weeks. The tumors were readily detected by MR and confidently identified when they were approximately 2-3 mm in size. The tumors were less well-defined on CT. The TRAMP-C2 tumors were characterized by amorphous sheets of poorly differentiated cells similar to a high-grade prostatic adenocarcinoma and frequent macroscopic peritoneal and lymph node metastases. In contrast, the NEPC's displayed a neuroendocrine morphology with polygonal cells arranged in nests and solid sheets and high count. There was a local invasion of the bladder and other adjacent tissues but no identifiable metastases. The TRAMP-C2 tumors were more hypoxic than the NEPC tumors. CONCLUSIONS: This novel preclinical orthotopic prostate cancer mouse model is suitable for either syngeneic or patient derived tumors and will be effective in developing and advancing the current selection of treatments for patients with prostate cancer.

[Ultrasonographic features of thyroid carcinoma of different sizes: comparison between medullary thyroid carcinomas and papillary thyroid carcinomas].

Objective: To investigate the ultrasonographic features of medullary thyroid carcinomas (MTCs) of different sizes and supply valid information for separating MTCs from papillary thyroid carcinomas (PTCs). Methods: There were 87 patients with MTC and 220 patients with PTC detected by ultrasonography and confirmed by pathology at Tianjin Medical University Cancer Institute and Hospital from June 2018 to March 2022. Nodules were divided into the large nodule group (the maximum diameter of the tumor was＞1 cm) and the small nodule group (the maximum diameter of the tumor was ≤1 cm). There were 97 cases in the small nodule group, including 28 cases of MTC and 69 cases of PTC. There were 210 cases in the large nodule group, including 59 cases of MTC and 151 cases of PTC. After stratification by thyroid nodules, ultrasonographic features of thyroid nodules and metastatic lymph nodes, preoperative serum calcitonin (CT) and carcinoembryonic antigen (CEA) levels were compared between MTC and PTC patients. Results: In the small nodule group, the proportion of MTCs exhibiting hypoecho, smooth margins, and having blood flow signals was higher than that of PTCs, with statistically significant differences (all P＜0.05). In the large nodule group, the proportion of MTCs showing cystic solidity, hypoecho, smooth margins, blood flow, and the type Ⅳvascular distribution was higher than PTCs, and the difference of calcification type between them was also statistically significant (all P＜0.05). In contrast, the differences in the number of lesions and aspect ratio between MTCs and PTCs were not statistically significant regardless of nodule size (all P＞0.05). In the small nodule group,6 metastatic lymph nodes of medullary thyroid carcinoma (LNM-MTC) and 11 metastatic lymph nodes of papillary thyroid carcinoma (LNM-PTC) were correctly diagnosed by ultrasound, respectively. The diagnostic compliance rate of ultrasound was 78.6% (22/28) and 78.3% (54/69), respectively, with no statistically significant difference (P=0.973). In the large nodule group, 28 LNM-MTC and 11 LNM-PTC were correctly diagnosed by ultrasound, respectively. The diagnostic compliance of ultrasound was 88.1% (52/59) and 73.5% (111/151), respectively, which was statistically significant (P=0.022). Among them, 82.1% of LNM-MTC and 56.6% of LNM-PTC showed abnormal blood flow signals, with a statistically significant difference (P=0.016). There were significant differences in preoperative serum CT and CEA levels of different sizes of MTCs (all P＜0.05). Conclusions: Different sizes of MTCs require diverse demonstrative criteria. Abnormal blood flow signal is of great significance in the diagnosis of LNM-MTC. Within the absence of ultrasonic characteristics, preoperative serum CT test can provide confidence for the diagnosis of MTC.

Small Cell Neuroendocrine Carcinoma of the Prostate on 18 F-DCFPyL and 18 F-FDG PET/CT.

ABSTRACT: A 51-year-old man with newly diagnosed small cell neuroendocrine carcinoma of the prostate was referred for a staging 18 F-DCFPyL PET/CT, which showed a solitary metastasis in the left acetabulum. Subsequent 18 F-FDG PET/CT showed intense uptake throughout the prostate as well as extensive avid pelvic and thoracic nodal disease and redemonstration of the left acetabular metastasis. Despite initial metabolic response to treatment, subsequent 18 F-FDG PET 8 months later revealed significant progression of nodal disease above and below the diaphragm, as well as multiple new sites of metastases.

[Mixed adenoneuroendocrine carcinoma: case report]. / Carcinoma adenoneuroendocrino mixto: reporte de caso.

Introducción: Mixed adenoneuroendocrine carcinoma is a rare tumor of the gastrointestinal tract with double differentiation into adenomatous and neuroendocrine carcinoma, each component with at least 30%. Case report: A 60-year-old female with acute abdominal pain. Surgical treatment was decided, finding a tumor at the level of the cecum and ascending colon, a right hemicolectomy and ileostomy were performed. Discussion: Mixed adenoneuroendocrine carcinoma can appear in various organs. They are highly malignant tumors, with a high risk of metastasis. Conclusions: These tumors do not present symptoms or specific radiological or laboratory findings; diagnosis depends on postoperative histopathological and immunohistochemical studies.

Introducción: El carcinoma adenoneuroendocrino mixto es un tumor raro del tracto gastrointestinal con doble diferenciación en carcinoma adenomatoso y neuroendocrino, cada componente con al menos el 30%. Caso clínico: Mujer de 60 años con cuadro de dolor abdominal agudo. Se decide tratamiento quirúrgico, encontrando un tumor a nivel de ciego y colon ascendente, y se realizan hemicolectomía derecha e ileostomía. Discusión: El carcinoma adenoneuroendocrino mixto puede aparecer en diversos órganos. Son tumores muy malignos, con alto riesgo de metástasis. Conclusiones: Estos tumores no presentan síntomas ni hallazgos radiológicos o de laboratorio específicos; el diagnóstico depende de estudios histopatológicos e inmunohistoquímicos posoperatorios.