A case of pulmonary tumor embolism diagnosed with respiratory distress immediately after FDG-PET/CT scan

Pulmonary tumor embolism in a maintenance hemodialysis patient with hepatocellular carcinoma

Patients with chronic kidney disease are already at an increased risk for pulmonary embolism, since loss of renal function rendered a procoagulant state. Further, malignant tumor is a well-established risk factor for pulmonary thromboembolism. Alternatively, occlusion of the pulmonary vasculature by tumor cells per se and associated thrombi may mimic thromboembolic disease. By comparison, however, report of pulmonary tumor embolism (PTE) in patients on maintenance hemodialysis (MHD) is exceedingly rare. A less vigilant clinician may have otherwise treated this situation as fluid overload or thromboembolic disorder. We herein described in an MHD patient such an unusual case of PTE, which was diagnosed by contrast-enhanced CT and PET/CT. As such, our work may expand the knowledge reserve of dialysis staffs about this rare complication of malignancy.

Renal Cell Carcinoma With Tumor Thrombus: A Case Series in Puerto Rico

INTRODUCTION

 Renal cell carcinoma (RCC) is one of the most common types of kidney cancer. While RCC tends to present as a localized tumor, a notable proportion may present with distant metastasis. In some instances, RCC may also present with intravascular tumor extension, often called tumor thrombus (TT). Its presence confers a worse prognosis and has important implications for the tumor's staging and treatment. Despite extensive documentation of RCC TT in the US, limited data exists regarding its presentation, management, and outcomes in Puerto Rico (PR). This study aims to broaden the available information on RCC TT, emphasizing surgical management and outcomes. We also provide descriptive data on patient demographics and clinical presentation to improve decision-making among clinicians caring for Puerto Rican men and women.

METHODS

 In this single-center, retrospective study, we evaluated patients who underwent partial or total nephrectomy at Saint Luke's Episcopal Medical Center between 2018 and 2022. Data was abstracted from electronic health records (EHR). Patients without documented evidence of TT during the peri-operative period were excluded from the study. A total of 220 patient records were evaluated, of which 12 met the inclusion criteria for the study. Cases were categorized using the latest RCC TT guidelines. Central tendency measurements were used to describe the sample distribution. The mean was considered to make assumptions regarding the prevalent observations, and the median was considered to rule out possible outliers. Categorical data were evaluated using proportion analyses, including TT extension level and BMI variables. Fisher's exact test evaluated the association between the World Health Organization/International Society of Urological Pathology (WHO/ISUP) grade and TT extension level.

RESULTS

 Most patients lacked TT-related symptoms. The most severe presenting symptom was a pulmonary embolism (8.3%). Hypertension (83.3%), BMI greater than 25 at the time of diagnosis (75%), and type 2 diabetes mellitus (66.7%) were the most common comorbid conditions within our cohort. Nearly 75% of patients underwent laparoscopic radical nephrectomy with TT resection. One left-sided level III case was managed by laparoscopic-assisted open radical nephrectomy with a right subcostal incision. There were zero intraoperative complications and two postoperative complications. The histopathological reports of all cases were consistent with clear cell carcinoma, and half of the cases (n=6) were WHO/ISUP G4. All patients are alive and free of disease.

CONCLUSION

 RCC is a common renal neoplasm in PR that can present with intravascular tumor extension. Our findings do not establish a definitive association between BMI, tumor size, WHO/ISUP grading, and TT extension level. Our study shows that laparoscopic removal of RCC TT is a safe and effective approach. However, the generalizability of our findings is limited by the study's design and sample size. Future research should focus on identifying predictive markers, establishing effective screening protocols, and determining if our hybrid approach has comparable outcomes to the standard open approach.

Renal Cell Carcinoma Presenting as Syncope due to Saddle Pulmonary Tumor Embolism

Pulmonary embolism (PE) is defined as the obstruction of the pulmonary artery or one of its branches by a blood clot, tumor, air, or fat emboli originating elsewhere in the body. A saddle PE occurs when the obstruction affects the bifurcation of the main pulmonary artery trunk. We present a case of a 46-year-old man who presented to our hospital due to an episode of syncope. Computed tomography angiography (CTA) of the chest showed extensive PE and abdominal CT scan showed a large 8 cm left renal mass with inferior vena cava (IVC) thrombus. Emergent embolectomy, left total nephrectomy, and IVC tumor removal were performed yielding the diagnosis of clear cell renal cell carcinoma (RCC). Interestingly, our patient did not experience any symptoms related to his RCC until the diagnosis of PE due to syncope, and the asymptomatic tumor was found out to be the possible cause of this PE due to the presence of tumor cells constituting the tumor embolus. It is thus recommended to improve the early screening process for RCC. Besides, clinicians should pay attention to patients presenting with uncharacteristic symptoms of RCC who might present with symptoms of saddle PE.

Biology of Cancer and PET Imaging: Pictorial Review

Development and spread of cancer is a multi-step and complex process which involves number of alterations, interactions and molecular networks. PET imaging is closely related with biology of cancer as it detects the cancer based on biological and pathological changes in tumor cells and tumor microenvironment. In this review article, biology of development and spread of cancer and role of PET imaging in Oncology was summarized and supported with various PET images demonstrating cancer spread patterns.