Imaging modalities and optimized imaging protocols in pregnant patients with cancer.

Medical imaging during pregnancy may be necessary to diagnose conditions that affect the outcome of the mother and fetus. Diagnosis and staging of cancer in pregnant women can be particularly challenging due to fear of inherent risk to the fetus, lack of standardized imaging protocols, and ethical challenges posed while choosing the best imaging option. Ultrasound and MRI, due to lack of ionizing radiation, are preferred over CT and nuclear imaging. The latter may be considered only if the benefits of imaging outweigh maternal and fetal risk without exceeding the cumulative established fetal radiation dose threshold. This article provides an overview of all currently available imaging options that can be used for imaging cancer during pregnancy to support the best possible maternal and fetal outcomes.

Mimics of cancer in pregnancy.

Pregnancy is a remarkable time of pronounced growth and development of the fetus. Benign pathologies outside of the uterus, including those containing hormonally responsive tissue which undergo physiologic changes and other incidentally identified lesions, may mimic malignancy on clinical evaluation and imaging. A detailed history and physical exam, ultrasound and non-contrast magnetic resonance imaging features and comparison with prior imaging if available may help to narrow the list of potential differential diagnoses. Follow-up imaging in the postpartum period is often vital to confirm benignity and, in some cases, sampling to confirm the diagnosis is necessary. This review will cover the clinical, pathological and multimodality imaging features of numerous potential mimickers of cancer in the setting of pregnancy organized by organ systems. The goal is to better equip abdominal radiologists to accurately identify benign disease and help guide further imaging or follow-up recommendations to avoid unnecessarily aggressive intervention and improve patient care.

Pseudoprogression in patients with uterine leiomyosarcoma treated with first-line single-agent doxorubicin.

AIM: To evaluate the incidence of pseudoprogression in patients with metastatic or inoperable uterine leiomyosarcoma (LMS) treated with first-line single-agent doxorubicin. METHODS: The Royal Marsden NHS Foundation Trust Sarcoma Unit database was searched to identify all patients with metastatic or inoperable LMS treated with first-line doxorubicin from January 2006 to January 2022. Patients with available computed tomography scans performed at baseline and during doxorubicin therapy were included. Response evaluation criteria in solid tumours v1.1 and Choi criteria were applied. Any increase in the sum of the longest diameter that decreased on the subsequent scan was labelled as pseudoprogression. RESULTS: The total number of patients evaluated was 52. In total, 19% (n = 10) of patients treated with doxorubicin showed pseudoprogression. However, pseudoprogression at the time of the second scan was not associated with time to doxorubicin failure. Choi criteria identified 30% (n = 3) of pseudoprogressors as responding. CONCLUSION: Despite the use of doxorubicin as first-line therapy for soft-tissue sarcomas for over 40 years, pseudoprogression has not been described. This retrospective study shows that pseudoprogression occurs in 19% of patients with metastatic/inoperable uterine LMS treated with first-line doxorubicin. Choi criteria were not consistently able to differentiate pseudoprogression from true progression. It is imperative that oncologists and radiologists are aware of this as symptomatically stable/improving patients may benefit from continued treatment despite initial radiological growth in tumour size.

False-positive lesions mimicking breast cancer on FDG PET and PET/CT.

OBJECTIVE: Incidental (18)F-FDG-avid breast lesions are commonly encountered in patients with cancer who undergo staging PET/CT. This pictorial essay discusses breast lesions that show increased FDG activity, mimicking breast cancer, with biopsy-confirmed benign diagnosis. CONCLUSION: Acute and chronic inflammation, physiologic lactation, and benign breast masses, including silicone granuloma, fat necrosis, fibroadenoma, and postsurgical changes, may show increased FDG uptake on PET/CT. These conditions can often be differentiated from malignancy by correlative imaging, including mammography, sonography, or MRI.

Diffusion-Weighted Magnetic Resonance Imaging in Ovarian Cancer: Exploiting Strengths and Understanding Limitations.

Detection, characterization, staging, and response assessment are key steps in the imaging pathway of ovarian cancer. The most common type, high grade serous ovarian cancer, often presents late, so that accurate disease staging and response assessment are required through imaging in order to improve patient management. Currently, computerized tomography (CT) is the most common method for these tasks, but due to its poor soft-tissue contrast, it is unable to quantify early response within lesions before shrinkage is observed by size criteria. Therefore, quantifiable techniques, such as diffusion-weighted magnetic resonance imaging (DW-MRI), which generates high contrast between tumor and healthy tissue, are increasingly being explored. This article discusses the basis of diffusion-weighted contrast and the technical issues that must be addressed in order to achieve optimal implementation and robust quantifiable diffusion-weighted metrics in the abdomen and pelvis. The role of DW-MRI in characterizing adnexal masses in order to distinguish benign from malignant disease, and to differentiate borderline from frankly invasive malignancy is discussed, emphasizing the importance of morphological imaging over diffusion-weighted metrics in this regard. Its key role in disease staging and predicting resectability in comparison to CT is addressed, including its valuable use as a biomarker for following response within individual lesions, where early changes in the apparent diffusion coefficient in peritoneal metastases may be detected. Finally, the task of implementing DW-MRI into clinical trials in order to validate this biomarker for clinical use are discussed, along with the trials that include it within their protocols.

Adenomyoepithelial tumors of the breast: imaging findings with histopathologic correlation.

OBJECTIVE: The purpose of this essay is to describe the imaging characteristics of adenomyoepithelial tumors of the breast. CONCLUSION: Adenomyoepithelial tumors of the breast are rare, and most are benign. The predominant mammographic and ultrasound feature is an irregular mass with suspicious imaging findings. This uncommon condition should be included in the differential diagnosis of noncalcified masses found on mammograms and of solid masses with associated hypervascularity on ultrasound images. Biopsy is necessary for histologic evaluation, and the management is surgical excision.

The "filarial dance" is not characteristic of filariasis: observations of "dancing megasperm" on high-resolution sonography in patients from nonendemic areas mimicking the filarial dance and a proposed mechanism for this phenomenon.

The objective of this series was to show that the sonographic appearance described as the "filarial dance" is not characteristic of filariasis but occurs in nonendemic areas as a manifestation of epididymal obstruction. An experienced observer documented cases after initial observation of the filarial dance in routine clinical practice using high-frequency linear array transducers. The filarial dance was described as excessive to-and-fro movement of echogenic particles within a prominent epididymis and graded 1 to 4 according to the extent and distribution of the abnormality. The country of birth, exposure to filarial infection or travel to a filarial-endemic area, previous scrotal surgery including vasectomy, any previous or current scrotal inflammatory disease, and any congenital testicular abnormalities were recorded. Over a 10-year period, sonographic appearances consistent with the filarial dance were observed in 18 patients (bilateral in 6). The mean patient age was 47.7 (range, 28-91) years. The abnormality was graded in the 24 affected testes as follows: grade 1, n = 3; grade 2, n = 8; grade 3, n = 8; and grade 4, n = 5. No patient had a history of filariasis or travel to an endemic area. Six of 18 patients (33.3%) had bilateral vasectomies; 5 (27.8%) had a history of epididymo-orchitis in the ipsilateral testis; 3 (16.7%) had previous scrotal surgery; and 4 (22.2%) had no relevant urologic history. We have described a sonographic appearance identical to the filarial dance in men with no history of filarial infection. Most had previous scrotal surgery or infection, suggesting that the filarial dance may not always be due to movement of filarial worms. The unifying condition in patients with filariasis and our patients is lymphatic obstruction, likely the underlying cause of the appearance in both groups.

Imaging features of primary sites and metastatic patterns of angiosarcoma.

Angiosarcomas are rare, aggressive soft tissue sarcomas originating from endothelial cells of lymphatic or vascular origin and associated with a poor prognosis. The clinical and imaging features of angiosarcomas are heterogeneous with a wide spectrum of findings involving any site of the body, but these most commonly present as cutaneous disease in the head and neck of elderly men. MRI and CT are complementary imaging techniques in assessing the extent of disease, focality and involvement of adjacent anatomical structures at the primary site of disease. CT plays an important role in the evaluation of metastatic disease. Given the wide range of imaging findings, correlation with clinical findings, specific risk factors and patterns of metastatic disease can help narrow the differential diagnosis. The final diagnosis should be confirmed with histopathology and immunohistochemistry in combination with clinical and imaging findings in a multidisciplinary setting with specialist sarcoma expertise. The purpose of this review is to describe the clinical and imaging features of primary sites and metastatic patterns of angiosarcomas utilising CT and MRI.