Positron emission tomography and leiomyomas: Clinicopathologic analysis of 3 cases of PET scan-positive leiomyomas and literature review

Intense FDG Uptake in Leiomyomatosis Peritonealis Disseminata With Fumarate Hydratase Deficiency

ABSTRACT

A 35-year-old woman with a history of laparoscopic myomectomy presented with repeated abdominal pain. Contrast-enhanced abdominal and pelvic CT showed multiple enhancing solid or mixed cystic and solid peritoneal masses, and an enhancing uterine mass. All these masses showed intense FDG uptake on FDG PET/CT. The intraperitoneal and uterine masses were surgically removed. The histological and immunohistochemical findings of the peritoneal lesions were consistent with leiomyomatosis peritonealis disseminata with fumarate hydratase deficiency, and the uterine mass was adenomyosis. This case indicates fumarate hydratase-deficient extrauterine leiomyoma can show intense FDG uptake mimicking malignancy.

MRI Evaluation of Uterine Masses for Risk of Leiomyosarcoma: A Consensus Statement

Laparoscopic myomectomy, a common gynecologic operation in premenopausal women, has become heavily regulated since 2014 following the dissemination of unsuspected uterine leiomyosarcoma (LMS) throughout the pelvis of a physician treated for symptomatic leiomyoma. Research since that time suggests a higher prevalence than previously suspected of uterine LMS in resected masses presumed to represent leiomyoma, as high as one in 770 women (0.13%). Though rare, the dissemination of an aggressive malignant neoplasm due to noncontained electromechanical morcellation in laparoscopic myomectomy is a devastating outcome. Gynecologic surgeons' desire for an evidence-based, noninvasive evaluation for LMS is driven by a clear need to avoid such harms while maintaining the availability of minimally invasive surgery for symptomatic leiomyoma. Laparoscopic gynecologists could rely upon the distinction of higher-risk uterine masses preoperatively to plan oncologic surgery (ie, potential hysterectomy) for patients with elevated risk for LMS and, conversely, to safely offer women with no or minimal indicators of elevated risk the fertility-preserving laparoscopic myomectomy. MRI evaluation for LMS may potentially serve this purpose in symptomatic women with leiomyomas. This evidence review and consensus statement defines imaging and disease-related terms to allow more uniform and reliable interpretation and identifies the highest priorities for future research on LMS evaluation.

Hypermetabolic Subserosal Uterine Leiomyoma With Synchronous Atypical Multiple Myeloma Mimicking Ovarian Malignancy With Multiple Bone Metastases on 18F-FDG PET/CT

ABSTRACT

Subserosal cystic myoma with intense FDG uptake can resemble malignant cystic ovarian tumor and may lead to a false-positive diagnosis. A 49-year-old woman presented with chest pain for 4 months, and the initial chest CT showed multiple bone lesions. 18F-FDG PET/CT revealed not only multiple osteolytic lesions with FDG uptake but also a highly FDG-avid mass abutting the right side of the uterus. Ovarian malignancy with multiple bone metastases was considered initially. Subsequent biopsy confirmed multiple myeloma, and a subserosal uterine myoma was diagnosed by transvaginal sonography.

Artificial Intelligence and COVID-19: Deep Learning Approaches for Diagnosis and Treatment

COVID-19 outbreak has put the whole world in an unprecedented difficult situation bringing life around the world to a frightening halt and claiming thousands of lives. Due to COVID-19's spread in 212 countries and territories and increasing numbers of infected cases and death tolls mounting to 5,212,172 and 334,915 (as of May 22 2020), it remains a real threat to the public health system. This paper renders a response to combat the virus through Artificial Intelligence (AI). Some Deep Learning (DL) methods have been illustrated to reach this goal, including Generative Adversarial Networks (GANs), Extreme Learning Machine (ELM), and Long/Short Term Memory (LSTM). It delineates an integrated bioinformatics approach in which different aspects of information from a continuum of structured and unstructured data sources are put together to form the user-friendly platforms for physicians and researchers. The main advantage of these AI-based platforms is to accelerate the process of diagnosis and treatment of the COVID-19 disease. The most recent related publications and medical reports were investigated with the purpose of choosing inputs and targets of the network that could facilitate reaching a reliable Artificial Neural Network-based tool for challenges associated with COVID-19. Furthermore, there are some specific inputs for each platform, including various forms of the data, such as clinical data and medical imaging which can improve the performance of the introduced approaches toward the best responses in practical applications.

FDG-PET for Assessment of Endometrial and Vulvar Cancer

Fluorodeoxyglucose positron emission tomography computed tomography (FDG-PET/CT) provides a comprehensive whole body evaluation in patients with endometrial and vulvar cancer. Here, we discuss the role of FDG-PET/CT in defining the disease extent in patients presenting with these cancers. Detection of lymph node and distant metastases has implications for staging, treatment planning, and patient prognosis. Procedures for image acquisition and interpretation for optimum accuracy and essential elements that should be included in the PET-CT report are described. Common imaging pitfalls are presented and illustrated with examples.

How to differentiate uterine leiomyosarcoma from leiomyoma with imaging

Uterine leiomyomas, the most frequent benign myomatous tumors of the uterus, often cannot be distinguished from malignant uterine leiomyosarcomas using clinical criteria. Furthermore, imaging differentiation between both entities is frequently challenging due to their potential overlapping features. Because a suspected leiomyoma is often managed conservatively or with minimally invasive treatments, the misdiagnosis of leiomyosarcoma for a benign leiomyoma could potentially result in significant treatment delays, therefore increasing morbidity and mortality. In this review, we provide an overview of the differences between leiomyoma and leiomyosarcoma, mainly focusing on imaging characteristics, but also briefly touching upon their demographic, histopathological and clinical differences. The main indications and limitations of available cross-sectional imaging techniques are discussed, including ultrasound, computed tomography, magnetic resonance imaging (MRI) and positron emission tomography/computed tomography. A particular emphasis is placed on the review of specific MRI features that may allow distinction between leiomyomas and leiomyosarcomas according to the most recent evidence in the literature. The potential contribution of texture analysis is also discussed. In order to help guide-imaging diagnosis, we provide an MRI-based diagnostic algorithm which takes into account morphological and functional features, both individually and in combination, in an attempt to optimize radiologic differentiation of leiomyomas from leiomyosarcomas.

Aberrant Hypermetabolism of Benign Uterine Leiomyoma on 18F-FDG PET/CT

Leiomyomas are prevalent benign smooth muscle tumors in the uterus, displaying variable degrees of FDG uptake on PET/CT. The glucose metabolism intensity of those lesions relies on biologic features and markedly increased FDG accumulation is more typically related to malignant diseases, as in the case of leiomyosarcomas. Notwithstanding that uterine fibroids typically exhibit mild to moderate FDG uptake, in this article we report a case of unexpectedly intense hypermetabolism of a benign uterine leiomyoma on a PET/CT scan performed for initial staging of a breast cancer patient.

A Giant Duodenal Leiomyoma Showing Increased Uptake on 18F-Fluorodeoxyglucose Positron Emission Tomography

Background

Although 18F-fluorodeoxyglucose positron emission tomography (FDG-PET/CT) is now widely used in their differential diagnosis, it is sometimes difficult to distinguish between benign and malignant diseases.

Case Presentation

A 44-year-old woman was found to have abnormalities on health screening. Magnetic resonance imaging for detailed examination showed an intra-abdominal tumor measuring 12 cm in the major axis near the cranial end of the uterus. Upper gastrointestinal tract endoscopy showed a tumor with an ulcer in the third part of the duodenum, involving half the circumference. Heterogeneous uptake was observed within the tumor on FDG-PET/CT. Based on these findings, the patient underwent surgery for suspected primary malignant lymphoma of the duodenum or gastrointestinal stromal tumor. Laparotomy revealed a 12 cm tumor in the third part of the duodenum. Partial duodenectomy and end-to-end duodenojejunostomy were performed. Pathological findings showed a solid tumor growing from the muscle layer of the duodenum to outside the serous membrane; based on immunostaining, it was diagnosed as a leiomyoma.

Conclusions

Duodenal leiomyomas are originally benign; to date, there have been no reports of uptake in duodenal leiomyomas on FDG-PET/CT; therefore, our case is rare. Leiomyomas should be considered in the differential diagnosis of duodenal neoplastic diseases.

Leiomyoma Originated From Inferior Vena Cava Mimicking an Adrenal Malignant Tumor on 18F-FDG PET/CT

PET/CT was performed on an asymptomatic 62-year-old woman with a suspected adrenal mass and revealed the lesion with high F-FDG avidity and inferior vena cava involvement. A malignant nonfunctioning adrenal tumor was suspected. However, histopathology of the resected lesion revealed a leiomyoma arising from the inferior vena cava.

FDG PET-CT of gynecologic cancers: pearls and pitfalls

FDG PET-CT plays an important role in treatment planning and in prognosis assessment of gynecologic cancer patients. Detection of hypermetabolic tissue with FDG PET, when combined with the high spatial resolution of CT, results in improved cancer detection and localization not afforded by either modality independently. This article is a primer for a radiologist performing PET-CT on gynecologic cancer patients and includes the imaging protocol, normal pattern of FDG distribution in the female pelvis and the lymph node drainage pathways from the gynecologic organs. Clinically relevant imaging findings that should be included in the report are discussed. Case examples illustrate how potential errors in exam interpretation can be avoided by concurrently performing a high-quality diagnostic CT with the FDG PET scan and by analyzing both the stand-alone and the fusion images.

Solitary fibrous tumor of the infratemporal fossa

Solitary fibrous tumors represent fewer than 2% of all soft tissue tumors, and only about 12-15% of them occur in the head and neck. We report a case of a 38-year-old male who presented with a six-month history of increasing right cheek swelling. Computed tomography of the paranasal sinuses with contrast demonstrated a well-circumscribed avidly enhancing mass in the right retroantral fat. On magnetic resonance imaging the lesion was homogenously slightly hyperintense to muscle on T1 weighted and T2 weighted images and enhanced avidly with contrast. Surgical resection was performed and pathology was consistent with solitary fibrous tumor. There have been very few reported cases of solitary fibrous tumors in the infratemporal fossa and none described as originating in the retroantral fat.

Renal vein leiomyoma: a rare entity with review of literature

Tumors of vascular origin are unusual. These tumors are predominantly malignant and commonly arise from the inferior vena cava. Benign smooth muscle tumors arising from renal vein are very rare. We present a case of leiomyoma of renal vein in a post-menopausal woman that clinically resembled a retroperitoneal paraganglioma.

ATL

Objective

Positron emission tomography/computed tomography (PET/CT) is an important tool in oncology for assessment of disease extent and recurrence. Recognition of benign fluorodeoxyglucose (FDG) uptake promotes correct interpretation of imaging data. This study assesses the appearance of benign uterine leiomyomas (ULs) on PET/CT and evaluates possible hormonal influences.

Patients and Methods

This was a retrospective study performed in a tertiary referral cancer center in Israel. One hundred fifty-two women with nongynecologic malignancies were referred for PET/CT scans, with incidental UL on imaging. Information on menopausal status and menstrual phase and on the use of oral contraceptives, hormone replacement therapy, and selective estrogen receptor modulators (SERM) was collected. Fluorodeoxyglucose uptake measured as standard uptake value (SUV) was obtained for UL, normal myometrium, and gluteus muscle. Changes associated with menopausal status, menstrual cycle phase, and the use of oral contraceptives, hormone replacement therapy, and SERM were assessed.

Results

The mean ± SD SUV in UL for the entire cohort was 1.39 ± 0.65 and was higher than in myometrium (1.24 ± 0.33) and gluteus muscle (0.48 ± 0.36). Fluorodeoxyglucose uptake was similar in UL and in myometrium during the preovulatory (1.42 ± 0.31 vs 1.23 ± 0.34) and postovulatory (1.23 ± 0.34 vs1.38 ± 0. 4) periods. During ovulation, SUV was significantly higher in UL (1.62 ± 0.39) than in normal myometrium (1.12 ± 0.15; P = 0.01). Uterine leiomyoma FDG uptake in premenopausal women (1.47 ± 0.32) was higher than in postmenopausal women (1.29 ± 0.41; P < 0.02). The UL/gluteus SUV ratio in patients on hormone replacement therapy (2.53 ± 0.23) was significantly higher than in untreated patients (1.27 ± 0.92; P = 0.05). Lower uptake was recorded in patients on SERM (SUV, 1.1 ± 0.24) than in untreated patients (SUV, 1.41 ± 0.36; P < 0.01).

Conclusion

Fluorine 18 FDG uptake in UL may be estrogen dependent. Endogenous estrogen and hormone replacement therapy increase FDG uptake, whereas withdrawal of estrogen by menopause or SERM decreases uptake.

[FDG-PET and endometrial cancer]

FDG-PET is widely used for the diagnosis, the staging and the search for recurrence of many tumors. However, there are currently no recommendations for its use in endometrial cancer. This article is an update of the literature data to enable everyone to form an opinion on the subject. Future prospects are considered.

Metastatic uterine leiomyosarcoma and eosinophilia

BACKGROUND

Uterine sarcomas account for approximately 3% to 7% of all uterine malignancies. Distinguishing benign and malignant myomas based on physical examination and imaging alone is challenging.

CASE

A postmenopausal woman with a history of leiomyomas presented to the Emergency Department with chest pain and a right upper lobe lung mass. Blood tests demonstrated profound eosinophilia (58,000/mm). Positron emission tomography-computed tomography scan to exclude distant disease as work-up for presumed lung cancer revealed increased tracer uptake in the lung mass and a pelvic mass. The patient died from complications of hypereosinophilia, and a postmortem diagnosis of metastatic uterine leiomyosarcoma was made.

CONCLUSION

Significant blood eosinophilia is uncommon in leiomyomas and should raise suspicion of malignant etiology for a pelvic mass.

Case of uterine leiomyoma showing fludeoxyglucose uptake on F-18 fludeoxyglucose positron emission tomography/computed tomography

In order not to over treat uterine leiomyoma and to avoid overlooking uterine leiomyosarcoma, a highly reliable diagnostic method has been thought. Occasionally, it is difficult to discriminate uterine leiomyoma from uterine leiomyosarcoma. Recently positron emission tomography/computed tomography (PET/CT) has been proved useful in assessing pelvic malignancies. We experienced a case of uterine leiomyoma showing increased F-18 fludeoxyglucose uptake on PET/CT in a postmenopausal woman. However, histological analysis demonstrated benign leiomyoma by the hysterectomy. Immunohistochemical analysis of glucose transporter-1 showed negative in leiomyoma. Our case indicates that uterine leiomyoma in a postmenopausal woman may show false positive result of PET/CT.

Spectrum of FDG PET/CT findings of uterine tumors

OBJECTIVE

The purpose of this article is to review FDG PET/CT and MRI findings in a variety of benign and malignant tumors of the uterus and to become familiar with the wide variety of FDG PET/CT findings of this entity.

CONCLUSION

Benign uterine tumors generally have mild FDG uptake, and leiomyoma rarely shows high uptake. Uterine malignant tumors generally have intense FDG uptake, whereas malignant uterine tumors that are small or that have low cellular density often show minimal uptake.

Imaging malignant and apparent malignant transformation of benign gynaecological disease

Common benign gynaecological diseases, such as leiomyoma, adenomyosis, endometriosis, and mature teratoma, rarely undergo malignant transformation. Benign transformations that may mimic malignancy include benign metastasizing leiomyoma, massive ovarian oedema, decidualization of endometrioma, and rupture of mature teratoma. The aim of this review is to provide a contemporary overview of imaging findings in malignant and apparent malignant transformation of benign gynaecological disease.

Enucleation of esophageal leiomyoma by video-assisted thoracic surgery

Thoracoscopic enucleation of benign distal esophageal leiomyoma is a minimally-invasive procedure that is comprised of four basic steps: (1) port placement and exposure, (2) dissection, (3) reconstruction, and (4) drain placement and closure. The procedure can be performed with minimal perioperative pain, excellent morbidity and mortality, and a high-degree of patient satisfaction. Some patients may experience mild dysphagia or dyspepsia in the postoperative interval, which is managed medically with proton pump inhibitors or surgically with antireflux repair.

Benign metastasizing leiomyoma of the lung: PET findings

We report the case of pulmonary benign metastasizing leiomyoma in an asymptomatic 64-year-old woman who underwent hysterectomy for a uterine leiomyoma 26 years earlier. Routine chest radiograph revealed bilateral diffuse nodular opacities within the pulmonary lobes. Thoracic computed tomography (CT) scan showed peripheral lung nodules that do not display contrast enhancement. Positron emission tomography (PET)-CT with 18F-fluorodeoxyglucose (18F-FDG PET-CT) demonstrated no significant metabolic activity of the nodules. The lesions were diagnosed as benign metastasizing leiomyoma by histopathologic examination. To our best knowledge, this is the first case studied combining CT and FDG PET-CT technique.

Incidence and characteristics of uterine leiomyomas with FDG uptake

OBJECTIVE

Uterine leiomyomas sometimes show focal 18F-fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET) images that may result in a false-positive diagnosis for malignant lesions. This study was conducted to investigate the incidence and characteristics of uterine leiomyomas that showed FDG uptake.

METHODS

We reviewed FDG-PET and pelvic magnetic resonance (MR) images of 477 pre-menopausal (pre-MP, age 42.1 +/- 7.3 years) and 880 post-MP (age 59.9 +/- 6.8 years) healthy women who underwent these tests as parts of cancer screening. Of 1357, 323 underwent annual cancer screening four times, 97 did three times, 191 did twice, and the rest were screened once. Focal FDG uptake (maximal standardized uptake value > 3.0) in the pelvis was localized and characterized on co-registered PET/MR images.

RESULTS

Uterine leiomyomas were found in 164 pre-MP and 338 post-MP women. FDG uptake was observed in 18 leiomyomas of 17 of the 164 (10.4%) pre-MP women and in 4 leiomyomas of 4 of the 338 (1.2%) post-MP women. The incidence was significantly higher in pre-MP women than in post-MP women (chi-square, P < 0.001). Of the 22, 13 showed signal intensity equal to or higher than that of the myometrium on T2-weighted MR images, which suggested abundant cellularity, whereas the majority of leiomyomas without FDG uptake showed low signal intensity. Of the 13 women, 12 examined more than twice showed substantial changes in the level of FDG uptake in leiomyomas each year with FDG uptake disappearing or newly appearing. These changes were observed frequently in relation with menopause or menstrual phases.

CONCLUSIONS

Leiomyomas with focal FDG uptake were seen in both pre-and post-MP women with a higher incidence in pre-MP women. Abundant cellularity and hormonal dependency may explain a part of the mechanisms of FDG uptake in leiomyomas. It is important to know that the level of FDG uptake in leiomyomas can change and newly appearing FDG uptake does not necessarily mean malignant transformation.

Standardized uptake values of uterine leiomyoma with 18F-FDG PET/CT: variation with age, size, degeneration, and contrast enhancement on MRI

OBJECTIVE

To assess the effect of age, size, the degree of degeneration, and contrast enhancement on magnetic resonance imaging (MRI) on 18F-fluoro-2-deoxyglucose (18F-FDG) uptake in uterine leiomyomas using quantitative standardized uptake values (SUVs).

METHODS

A total of 61 leiomyomas of 41 patients, who underwent combined positron emission tomography/computed tomography (PET/CT) using 18F-FDG and contrast-enhanced MRI were included in this study. Sixty-one leiomyomas were divided into two groups: "non-degenerated" leiomyomas showing distinct low signal intensity on T2-weighted images and intermediate signal intensity on T1-weighted images, and "degenerated" leiomyomas showing other types of signal intensity. Sixty-one leiomyomas were also divided into two groups of "strongly enhancing" leiomyomas and "weakly enhancing" leiomyomas in terms of their degree of contrast enhancement on MRI.

RESULTS

The mean values of the maximum and average SUVs for the total of 61 leiomyomas were 2.34 +/- 0.75 (range 1.59-5.15) and 1.74 +/- 0.50 (0.66-3.95), respectively. There was a moderate negative correlation between the maximum and average SUVs and age (r = -0.43 and P = 0.00016, r = -0.31 and P = 0.029, respectively). Although there was a mild positive correlation between maximum SUV and size (r = 0.35 and P = 0.011), there was no significant difference between average SUV and size. Although there was no significant difference in average SUV between "degenerated" and "non-degenerated" leiomyomas, the maximum SUV of "degenerated" leiomyomas was significantly higher than that of "non-degenerated" leiomyomas (P = 0.0012). The degree of contrast enhancement on MRI was not significantly correlated with 18F-FDG uptake.

CONCLUSIONS

Mild or moderate uptake of 18F-FDG is often observed in uterine leiomyoma and declines with age, and should not be confused with malignant accumulation.

Preoperative evaluation of pelvic masses with combined 18F-fluorodeoxyglucose positron emission tomography and computed tomography

OBJECTIVE

To prospectively evaluate the diagnostic value of combined 18F-fluorodeoxyglucose position emission tomography and computed tomography (FDG-PET/CT) to discriminate malignant or borderline malignant tumors from benign pelvic masses.

METHODS

A prospective study of 30 women with suspected ovarian cancer who presented from July 2006 through August 2007. Selection was based on evidence from ultrasound, magnetic resonance imaging, and rising tumor marker levels. All patients underwent FDG-PET/CT prior to standard debulking surgery for a pelvic mass.

RESULTS

The sensitivity and specificity of FDG-PET/CT to detect malignant or borderline malignant pelvic tumors were 71.4% and 81.3%, respectively. The sensitivity and specificity of FDG-PET/CT to detect ovarian cancer were 100% and 85.0%, respectively. The maximum standardized uptake value in borderline tumors was significantly lower compared with malignant tumors, but not significantly different compared with benign tumors.

CONCLUSION

FDG-PET/CT had a high diagnostic value in differentiating between malignant and benign tumors, and a low diagnostic value in differentiating between borderline malignant and benign tumors.

Leiomyoma of the adrenal gland presenting as a non-functioning adrenal incidentaloma: case report and review of the literature

A 31-year-old woman was incidentally found to have a large right adrenal mass by computed tomography imaging and underwent a workup that included endocrinological evaluation and positron emission tomography imaging. Laboratory results revealed the mass to be non-functioning. Imaging studies revealed a 9-cm heterogeneous mass that was not FDG avid. Because of concern for adrenal cortical carcinoma, the patient underwent a successful right adrenalectomy. Pathology examination demonstrated an 11-cm circumscribed mass consisting of uniform spindle cells without nuclear pleomorphism, necrosis, or mitotic activity. The diagnosis of leiomyoma was supported by a panel of immunohistochemical stains. Adrenal leiomyomas have been reported in the literature, although most are small and not preoperatively suspicious for malignancy. This case illustrates that benign tumors such as leiomyomas, when large and heterogeneous on imaging, can clinically mimic adrenal cortical carcinomas and should be included in the differential diagnosis of adrenal incidentalomas.