Nilendu C. Purandare

From the 8th International Cancer Congress

Isolated liver metastasis from prostate cancer is exceedingly rare. Prostate-specific membrane antigen–positron emission tomography/computed tomography has become the one-stop shop imaging in prostate cancer, but the uptake is a relatively nonspecific tracer and its expression can be seen in a plethora of nonprostatic solid tumors. We report one such example of an oligometastatic prostate cancer who presented with an isolated liver lesion which turned out to be an incidental hepatocellular carcinoma, thus representing a potentially unique diagnostic challenge.

Fibrolamellar hepatocellular carcinoma (HCC) is a variant of HCC. It is a malignant tumor, but its imaging features often overlap focal nodular hyperplasia, which is a benign entity. FDG PET/CT is also not much help in these cases because both lesions do not concentrate FDG. We present one such case of fibrolamellar HCC with FAPI PET/CT positivity.

Epithelioid angiosarcoma is a rare subtype of angiosarcoma, with metastases occurring in more than 50% of cases and the lung is the most organ which is involved. Whole-body fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) has demonstrated its clinical utility in the early detection of metastases in angiosarcoma. It is helpful to differentiate between benign lesions with low FDG uptake as compared to malignancies with high FDG avidity. Here, we present a rare case of a young man with epithelioid angiosarcoma, in which FDG PET/CT has demonstrated metastatic sites (especially lung metastases).

Sporadic cerebellar hemangioblastomas are rare with majority of these tumors presenting as a part of von Hippel–Lindau syndrome. We demonstrate an unusual case of a symptomatic sporadic cerebellar hemangioblastoma mimicking a meningioma on MRI and ⁶⁸Ga-DOTANOC PET imaging.

Mantle cell lymphoma is a rare and aggressive non-Hodgkin lymphoma with a high propensity for extranodal involvement, typically seen in the liver, marrow, and gastrointestinal system. Being an FDG-avid disease and a sensitive modality for detecting both nodal and extranodal disease, FDG PET/CT is recommended in the workup of mantle cell lymphoma. We present a rare pattern of cutaneous involvement of the head-neck region in a patient with mantle cell lymphoma, which can be described on FDG PET/CT as a “hood sign.”

Sunitinib is one of the most commonly used multikinase inhibitors for metastatic renal cell carcinoma. Myositis is one of the rarest known adverse effects of sunitinib. Presenting herewith one such case with its relevant imaging findings on FDG PET/CT and ultrasound.

Objective: The objective is to evaluate incidental detection of COVID-19 lung involvement in asymptomatic individuals who undergo fluorodeoxyglucose (FDG) positron emission tomography-computerized tomography (PET/CT) scans for oncologic indications. Patients and Methods: The study was conducted in a tertiary care oncology hospital and included patients who were asymptomatic for COVID-19 infection and underwent FDG PET/CT scans for standard oncologic indications between April 15, 2020, and September 30, 2020. Patients who showed CO-RADS category 4/5 changes (high level of suspicion) on the CT chest component of the PET/CT study were considered for analysis. CT severity score, presence of FDG uptake, and maximum standardized uptake value of FDG avid lung involvement were noted and correlated with reverse transcriptase-polymerase chain reaction (RT-PCR) test. Results: 1982 PET/CT scans were performed, 78 (3.9%) patients showed lung changes with high degree of suspicion of COVID-19 pneumonia (CO-RADS 4/5). Hematolymphoid and head-neck cancer were the most common tumor types (23%), and restaging/response evaluation was the most common PET/CT indication. Of the patients who underwent RT-PCR testing, 70% showed a positive result. The mean CT severity score was 6 (standard deviation 5.9) with no significant difference seen between the RT-PCR positive and negative groups. FDG avidity in lung lesions was noted in 41 out 57 (72%) patients. A significant correlation was seen between the RT-PCR positivity and FDG uptake in lung lesions. Conclusion: A small but significant proportion of patients undergoing routine oncologic PET/CT scans showed incidental COVID-19 lung involvement. Lung involvement in these asymptomatic patients showed a low CT severity score in all patients and FDG avidity in majority. Timely detection of such incidental cases can initiate further confirmatory RT-PCR testing and isolation measures that not only influence patient's cancer treatment protocols but also have a larger community impact of limiting the spread of infection.