PET/CT in a Patient With Adenoma Malignum of the Uterine Cervix

Adenocarcinoma of the uterine cervix, gastric-type (GAS): a review of the literature focused on pathology and multimodality imaging

Adenocarcinoma of the uterine cervix, gastric-type (GAS) is a rare, well-differentiated subtype of HPV-independent endocervical adenocarcinoma. It classically arises in middle-aged women with symptoms, including profuse watery vaginal discharge and abnormal uterine bleeding. Given the rarity of this disease, misdiagnosis is common and prognosis remains poorly defined. Distinct pathology and imaging findings can aid in diagnosis. A literature review was performed to ascertain recurring pathologic and radiologic characteristics of GAS. Key pathologic features of GAS include cytologically benign appearing mucinous glands that infiltrate into the deep stroma and may demonstrate lymphovascular or perineural invasion. Multiple imaging modalities including transvaginal ultrasound, CT, and MRI may aid in diagnosis of GAS, which characteristically is seen as a multicystic mass with solid components. MRI in particular is the preferred imaging study because it offers the best chance of identifying a potential solid component, which is key to making the diagnosis of GAS and distinguishing it from other endocervical diseases processes. Careful attention to histopathologic and radiologic details, in conjunction with clinical correlation, is necessary to distinguish GAS from other multicystic cervical lesions.

PET/CT Variants and Pitfalls in Gynecological Cancers

The role of hybrid imaging with 2-[18F] flourodeoxyglucose (FDG) positron emission tomography and computed tomography (PET/CT) is continuously evolving and now considered standard practice in evaluation of disease stage, treatment response, recurrent disease and follow-up for numerous primary malignancies. In gynecological malignancies FDG PET/CT plays an important role, not only in the assessment of disease in the pre-and post-therapy setting, but also in radiation therapy (RT) planning by defining the metabolically active gross tumor volume (GTV. The glucose analogue radiotracer, FDG, is by far the most utilized radiotracer in PET/CT and is typically seen with high uptake in malignant cells. The radiotracer FDG has a high sensitivity but low specificity for malignancy, as benign processes with an inflammatory response for example infection, are also FDG-avid. In the evaluation of the female pelvic region an awareness of potential confounding factors in the interpretation of FDG is essential as variations of FDG uptake occur in accordance with the menstrual cycle and the menopausal state. Incidental imaging findings in the female genital can pose differential diagnostic challenges as false-positive and false-negative findings in benign and malignant processes are not uncommon. Gynecological malignancies continue to pose major public health problems with cervical cancer as the fourth most common cancer in women ranking after breast cancer, colorectal cancer and lung cancer. Familiarity with frequently encountered benign and malignant variants and pitfalls in FDG PET/CT in the female pelvic region can aid the reader in differential diagnostic considerations.

Adenoma Malignum Presenting With Profound Hyponatremia

BACKGROUND

Adenoma malignum of the cervix (also referred to as minimal deviation adenocarcinoma) is a rare malignancy. Although previous reports have described adenoma malignum presenting with mucinous vaginal discharge, no reports to our knowledge have described a presentation with profound hyponatremia due to fluid losses.

CASE

We present a case of adenoma malignum in a 52-year-old woman who presented with substantial watery vaginal discharge and profound hyponatremia.

CONCLUSION

Despite being a rare cervical tumour, adenoma malignum should be considered in the differential diagnosis of watery vaginal discharge. This tumour can present with severe electrolyte disturbances.