Malignancy Rate Low Among Incidental Splenic Masses Detected During CT

Follow-up of incidental splenic masses noted during abdominal CT may not be indicated, according to a study published in the journal Radiology.

Researchers from Beth Israel Deaconess Medical Center in Boston, Mass., performed a retrospective study to evaluate whether an incidentally noted splenic mass at abdominal CT require further imaging work-up.

The researchers reviewed images, follow-up examinations, and electronic medical records of 379 patients with splenic masses detected during abdominal CT examinations; 214 (56.5 percent) were women and 165 (43.5 percent) men, mean age of 59.3 years. The patients were divided into three groups:

• Group 1: 145 (38.3 percent) patients with a history of malignancy
• Group 2: 29 (7.6 percent) patients with symptoms such as weight loss, fever, or pain related to the left upper quadrant and epigastrium
• Group 3: 205 (54.1 percent) patients with incidental findings

The final diagnoses of the causes of the masses were confirmed with imaging follow-up (83.9 percent), clinical follow-up (13.7 percent), and pathologic examination (2.4 percent).

The results showed the incidence of malignant splenic masses was 49 of 145 (33.8 percent) in the malignancy group, eight of 29 (27.6 percent) in the symptomatic group, and two of 205 (1 percent) in the incidental group. The incidental group consisted of new diagnoses of lymphoma in one (50 percent) patient and metastases from ovarian carcinoma in one (50 percent) patient. Malignant splenic masses in the incidental group were not indeterminate, because synchronous tumors in other organs were diagnostic of malignancy.

The researchers concluded that with an incidental splenic mass, the likelihood of malignancy is very low (1 percent) and follow-up of incidental splenic masses may not be indicated.