Detection of primary choriocarcinoma in the mediastinum by F-18 FDG positron emission tomography

Primary mediastinal choriocarcinoma in an 18-year-old male with pulmonary and brain metastasis: A case report

Primary mediastinal choriocarcinoma, also known as non-pregnant choriocarcinoma, is a rare malignancy unrelated to pregnancy, with a higher incidence in males. And primary mediastinal choriocarcinoma is mostly associated with organ and lymph node metastasis, with rapid progression and poor prognosis. Here, we report an extremely rare case of the primary anterior mediastinal choriocarcinoma that occurred in an 18-year-old man with multiple metastases of the lung and brain.

Primary Pancreatic Choriocarcinoma With Hepatic Metastases on 18 F-FDG PET/CT

ABSTRACT

Pancreatic choriocarcinoma is a rare disease, and concurrent hepatic metastases have not previously been reported. We report a case of a 46-year-old woman with significantly elevated human chorionic gonadotropin β levels, and 18 F-FDG PET/CT demonstrated FDG-avid lesions in the pancreatic head, liver, and lymph nodes. The initial diagnosis of pancreatic choriocarcinoma with metastases was made and further confirmed by PET/CT-guided biopsy. 125 I seeds were then implanted to treat the pancreatic choriocarcinoma lesions, which effectively reduced the tumor size. New hepatic metastases have been observed after 5 months, and this case had an overall survival of 10 months.

18F-FDG PET/CT May Predict Tumor Type and Risk Score in Gestational Trophoblastic Disease

PURPOSE

The aim of this study was to investigate the role of 18F-FDG PET/CT in predicting pathological prognostic factors, including tumor type and International Federation of Gynecology and Obstetrics (FIGO) score, in gestational trophoblastic disease (GTD).

METHODS

Retrospective monocentric study including 24 consecutive patients who underwent to 18F-FDG PET/CT from May 2005 to March 2021 for GTD staging purpose. The following semiquantitative PET parameters were measured from the primary tumor and used for the analysis: maximum standardized uptake value (SUVmax), SUVmean, metabolic tumor volume (MTV) and total lesion glycolisis (TLG). Statistical analysis included Spearman correlation coefficient to evaluate the correlations between imaging parameters and tumor type (nonmolar trophoblastic vs postmolar trophoblastic tumors) and risk groups (high vs low, defined according to the FIGO score), whereas area under the curve (AUC) of the receiver operating characteristic (ROC) curve was used to assess the predictive value of the PET parameters. Mann-Whitney U test was used to further describe the parameter's potential in differentiating the populations.

RESULTS

SUVmax and SUVmean resulted fair (AUC, 0.783; 95% confidence interval [CI], 0.56-0.95) and good (AUC, 0.811; 95% CI, 0.59-0.97) predictors of tumor type, respectively, showing a low (ρ = 0.489, adjusted P = 0.030) and moderate (ρ = 0.538, adjusted P = 0.027) correlation. According to FIGO score, TLG was instead a fair predictor (AUC, 0.770; 95% CI, 0.50-0.99) for patient risk stratification.

CONCLUSIONS

18F-FDG PET parameters have a role in predicting GTD pathological prognostic factors, with SUVmax and SUVmean being predictive for tumor type and TLG for risk stratification.

Imaging of Hepatic Ectopic Pregnancy by 18F-FDG PET/CT

Hepatic ectopic pregnancy is an uncommon form of extrauterine pregnancy. A 31-year-old woman had acute abdominal pain and distention. Laboratory examination showed significantly increased serum β-human chorionic gonadotropin level. Both ultrasound and MRI identified a lesion located at the right lobe of the liver. FDG PET/CT was performed to determine whether the other causes of elevated β-human chorionic gonadotropin level, which showed an oval mass with mid peripherally increased FDG activity. After surgery, pathological results confirmed a diagnosis of hepatic ectopic pregnancy.

Primary pancreatic choriocarcinoma revealed on FDG PET/CT

Choriocarcinoma is a cancer that usually occurs in the uterus during pregnancy. Extragonadal choriocarcinoma, although very rare, can occur. The diagnostic dilatation and curettage of the uterus in a 28-year-old woman who had vaginal bleeding and elevated human chorionic gonadotrophin level failed to identify any abnormality. FDG PET/CT revealed abnormal activity in the head of the pancreas. Pathological examination after partial pancreatectomy demonstrated primary choriocarcinoma in the pancreas.

Primary choriocarcinoma in mediastinum with multiple lung metastases in a male patient: A case report and a review of the literature

Primary choriocarcinoma is a rare malignant tumor, particularly in men. The tumor, mostly found in the gastrointestinal system and mediastinum, often metastasizes early with poor therapeutic effects and prognosis. Herein, we present a male patient with primary mediastinum choriocarcinoma and widespread lung metastases. The disease progressed rapidly with little therapeutic effect from chemotherapy. The patient died of this disease 75 days after initial symptom presentations. Literature review found only 41 cases of primary choriocarcinoma reported in the mediastinum. This case highlights the importance of keeping primary choriocarcinoma in the differentials for mediastinum tumors in young men. Sex hormone testing is helpful to confirm diagnosis. Early biopsy should be performed to confirm pathologic diagnose, and early surgery and chemotherapy should be considered to improve the cure rate of this disease.

Role of 18F-FDG PET in the management of gestational trophoblastic neoplasia

PURPOSE

Gestational trophoblastic neoplasia (GTN) is a rare and aggressive tumour that is usually sensitive to chemotherapy. The usefulness of conventional imaging modalities in evaluating treatment response is limited, mainly due to the difficulty in differentiating between residual tumour tissue and necrosis. The aim of the present study was to evaluate the role of FDG PET or PET/CT in primary staging and in monitoring treatment efficacy. The effect of FDG PET and combined PET/CT on the management of patients with GTN was also evaluated comparing the differences between standard treatments based on conventional imaging and alternative treatments based on PET.

METHODS

This retrospective study included 41 patients with GTN referred to San Raffaele Hospital between 2002 and 2010. All patients were studied by either PET or PET/CT in addition to conventional imaging. Of the 41 patients, 38 were evaluated for primary staging of GTN and 3 patients for chemotherapy resistance after first-line chemotherapy performed in other Institutions. To validate the PET data, PET and PET/CT findings were compared with those from conventional imaging, including transvaginal ultrasonography (TV-US) in those with uterine disease, CT and chest plain radiography in those with lung disease and whole-body CT in those with systemic metastases. Conventional imaging was considered positive for the presence of uterine disease and/or metastases when abnormal findings relating to GTN were reported. PET and PET/CT were considered concordant with conventional imaging when metabolic active disease was detected at the sites corresponding to the pathological findings on conventional imaging. In addition, in 12 of the 41 patients showing extrauterine disease, FDG PET/CT was repeated to monitor treatment efficacy, in 8 after normalization of beta human chorionic gonadotropin (βHCG) and in 4 with βHCG resistance. In some patients, PET or PET/CT findings led to an alternative nonconventional treatment, and this was considered a change in patient management for the study analysis.

RESULTS

When compared to TV-US, chest radiography and CT for staging, PET showed a concordance in 91 %, 84 % and 81 % of patients, respectively. In 8 of the 41 patients with extrauterine disease during staging, PET/CT showed a complete response to therapy after βHCG normalization. PET and PET/CT identified the sites of persistent disease in all seven high-risk patients with βHCG resistance, of whom four underwent second-line chemotherapy, two surgical removal of resistant disease instead of additional chemotherapy, and one surgical removal of resistant disease and second-line chemotherapy with subsequent negative βHCG.

CONCLUSION

In staging, PET cannot replace conventional imaging and does not show any information in addition to that shown by conventional imaging. The additional value of PET/CT in GTN with respect to conventional imaging is found in patients with high-risk disease. PET can identify the sites of primary and/or metastatic disease in patients with persistent high levels of βHCG after first-line chemotherapy and may be of additional value in patient management for guiding alternative treatment.

Adult extragonadal germ cell tumors

OBJECTIVE

The purpose of this article is to describe the key imaging features of primary and metastatic extragonadal germ cell tumors in adults.

CONCLUSION

Extragonadal germ cell tumors primarily affect men during the third and fourth decades of life. Their imaging characteristics are nonspecific, and extragonadal germ cell tumors should always be included in the differential diagnosis of a midline anterior mediastinal or retroperitoneal mass. Levels of human chorionic gonadotropin or α-fetoprotein or both may be elevated, depending on the histologic subtype.

Utility of positron emission tomography in the mediastinum: moving beyond lung and esophageal cancer staging

PET and PET-CT are rapidly evolving as modalities of thoracic imaging. In the mediastinum, PET can provide information to distinguish thymic hyperplasia from neoplasia, although the use of this imaging for this purpose is not accepted uniformly as necessary. PET is the standard of care in staging and follow-up of mediastinal lymphoma and in follow-up of metastatic seminomas after chemotherapy. Mycobacterial/fungal infections, sarcoidosis, and brown fat can mimic malignant findings on PET in the mediastinum.