The Incidental Splenic Mass at CT: Does It Need Further Work-up? An Observational Study.

Purpose To evaluate whether an incidentally noted splenic mass at abdominal computed tomography (CT) requires further imaging work-up. Materials and Methods In this institutional review board-approved HIPAA-compliant retrospective study, a search of a CT database was performed for patients with splenic masses at CT examinations of the abdomen and chest from 2002 to 2008. Patients were divided into three groups: group 1, patients with a history of malignancy; group 2, patients with symptoms such as weight loss, fever, or pain related to the left upper quadrant and epigastrium; and group 3, patients with incidental findings. Patients' CT scans, follow-up examinations, and electronic medical records were reviewed. Final diagnoses of the causes of the masses were confirmed with imaging follow-up (83.9%), clinical follow-up (13.7%), and pathologic examination (2.4%). Results This study included 379 patients, 214 (56.5%) women and 165 (43.5%) men, with a mean age ± standard deviation of 59.3 years ± 15.3 (range, 21-97 years). There were 145 (38.3%) patients in the malignancy group, 29 (7.6%) patients in the symptomatic group, and 205 (54.1%) patients in the incidental group. The incidence of malignant splenic masses was 49 of 145 (33.8%) in the malignancy group, eight of 29 (27.6%) in the symptomatic group, and two of 205 (1.0%) in the incidental group (P < .0001). The incidental group consisted of new diagnoses of lymphoma in one (50%) patient and metastases from ovarian carcinoma in one (50%) patient. Malignant splenic masses in the incidental group were not indeterminate, because synchronous tumors in other organs were diagnostic of malignancy. Conclusion In an incidental splenic mass, the likelihood of malignancy is very low (1.0%). Therefore, follow-up of incidental splenic masses may not be indicated. © RSNA, 2018.

Mammary-type myofibroblastoma of the liver: multi-modality imaging features with histopathologic correlation.

A 46-year-old woman with an incidentally discovered hepatic mass at the time of echocardiography underwent additional imaging for characterization. Ultrasound demonstrated a 5.3 cm solid hyperechoic mass. Computed tomography and magnetic resonance imaging showed intratumoral fat and nodular foci of progressive enhancement. The patient underwent surgical resection, with the mass demonstrating histopathologic and immunohistochemical features diagnostic of a hepatic mammary-type myofibroblastoma. We present herein the clinical, imaging, and pathologic features in this unique case of hepatic mammary-type myofibroblastoma. Mammary-type myofibroblastoma is a benign spindle cell tumor typically composed of groups of myofibroblasts within bands of hyalinized collagenous stroma. Some tumors also have an adipocytic component. The tumor is nearly exclusively seen in the breast and although extramammary soft tissue locations have been described, to our knowledge, this is the first reported case in the liver or any visceral site. Although rare, radiologists and clinicians should, therefore, be aware of the possibility of a mammary-type myofibroblastoma when a solid, non-encapsulated, fat containing tumor in the liver is encountered.