Two Cases of Biphasic Synovial Sarcoma With Expression of PAX8 and ER: A Diagnostic Pitfall

Synovial sarcoma (SS) is a high-grade malignant neoplasm frequently arising in the deep soft tissue of the lower and upper extremities of young adults. Primary SS in the pelvis is extremely rare with scattered case reports. It often causes a diagnostic challenge in small biopsy and/or with aberrant expression of immunohistochemical markers. Here, we report 2 unusual cases of SS in the pelvis. Microscopically both cases present with biphasic morphology including spindle and epithelioid cells. In addition, the tumor cells in both cases expressed PAX8 and estrogen receptor. PAX8 is a transcription factor usually expressed in tumors of thyroid gland, kidney, and Müllerian system origin. The expression of PAX8 especially with co-expression of estrogen receptor can be misleading and result in a diagnosis of Müllerian tumors in female patients with pelvic masses. The diagnosis of SS for both cases was confirmed either with the fluorescence in situ hybridization or reverse transcription polymerase chain reaction showing a SS18 (SYT) (18q11) gene rearrangement. It is imperative to include SS in the differential diagnosis for malignant neoplasms exhibiting monotonous spindle cells (monophasic SS) and biphasic mixed monotonous spindle and epithelioid tumor cells in female patients with a pelvic mass. Molecular study for SS18 translocation is essential for the diagnosis in such cases.

Progress and Future Trends in PET/CT and PET/MRI Molecular Imaging Approaches for Breast Cancer

Breast cancer is a major disease with high morbidity and mortality in women worldwide. Increased use of imaging biomarkers has been shown to add more information with clinical utility in the detection and evaluation of breast cancer. To date, numerous studies related to PET-based imaging in breast cancer have been published. Here, we review available studies on the clinical utility of different PET-based molecular imaging methods in breast cancer diagnosis, staging, distant-metastasis detection, therapeutic and prognostic prediction, and evaluation of therapeutic responses. For primary breast cancer, PET/MRI performed similarly to MRI but better than PET/CT. PET/CT and PET/MRI both have higher sensitivity than MRI in the detection of axillary and extra-axillary nodal metastases. For distant metastases, PET/CT has better performance in the detection of lung metastasis, while PET/MRI performs better in the liver and bone. Additionally, PET/CT is superior in terms of monitoring local recurrence. The progress in novel radiotracers and PET radiomics presents opportunities to reclassify tumors by combining their fine anatomical features with molecular characteristics and develop a beneficial pathway from bench to bedside to predict the treatment response and prognosis of breast cancer. However, further investigation is still needed before application of these modalities in clinical practice. In conclusion, PET-based imaging is not suitable for early-stage breast cancer, but it adds value in identifying regional nodal disease and distant metastases as an adjuvant to standard diagnostic imaging. Recent advances in imaging techniques would further widen the comprehensive and convergent applications of PET approaches in the clinical management of breast cancer.

Advances in Functional Imaging in the Assessment of Head and Neck Cancer

This article discusses the application of fludeoxyglucose PET/computed tomography (CT) technology in head and neck cancer diagnosis and management, as well as advantages and disadvantages relative to traditional imaging modalities. A successful scan relies on precise patient preparation, and compliance to specific protocols before and during the scan. Finally, this article briefly introduces a PET/CT scan recently approved by the Food and Drug Administration for neuroendocrine tumors.

False positive for malignancy of a lung nodule on FDG PET/CT scans--a lesion with high FDG uptake but stable in size

A highly F-18 fluorodeoxyglucose-avid lung nodule was stable in both size and metabolic activity over 4 months. This was most likely nonneoplastic because a true tumor would grown in volume overtime. The high level of energy consumption was contributing functional activities or by inflammatory cells. Because the speed of tumor growth is proportional to its energy consumption, we consider the higher the metabolic activity of a lesion, the less likely of malignant if it was stable in size over time.

Does colon cancer ever metastasize to bone first? a temporal analysis of colorectal cancer progression

Background

It is well recognized that colorectal cancer does not frequently metastasize to bone. The aim of this retrospective study was to establish whether colorectal cancer ever bypasses other organs and metastasizes directly to bone and whether the presence of lung lesions is superior to liver as a better predictor of the likelihood and timing of bone metastasis.

Methods

We performed a retrospective analysis on patients with a clinical diagnosis of colon cancer referred for staging using whole-body ¹⁸F-FDG PET and CT or PET/CT. We combined PET and CT reports from 252 individuals with information concerning patient history, other imaging modalities, and treatments to analyze disease progression.

Results

No patient had isolated osseous metastasis at the time of diagnosis, and none developed isolated bone metastasis without other organ involvement during our survey period. It took significantly longer for colorectal cancer patients to develop metastasis to the lungs (23.3 months) or to bone (21.2 months) than to the liver (9.8 months). Conclusion: Metastasis only to bone without other organ involvement in colorectal cancer patients is extremely rare, perhaps more rare than we previously thought. Our findings suggest that resistant metastasis to the lungs predicts potential disease progression to bone in the colorectal cancer population better than liver metastasis does.

18F-Fluorodeoxy glucose (FDG) uptake in nontraumatic bilateral adrenal hemorrhage secondary to heparin-associated thrombocytopenia syndrome (HATS)—a case report

(18)F-Fluorodeoxy glucose (FDG) activity reflects tissue glucose metabolism; malignancies, metastases, and acute infections have relatively increased FDG activity reflecting increased glucose metabolism. Benign adrenal disease demonstrating mild FDG uptake can be worrisome for metastasis in patients with a history of malignancy. Our patient with breast and colon cancer developed gastrointestinal bleeding on heparin therapy, enlarged adrenals with heterogeneous attenuation consistent with hemorrhage and blood clots as seen on abdominal computed tomography scan, and as abnormal intense FDG activity in the bilateral adrenal glands on positron emission tomography scan.