Thirteen patients (males= 7, females= 6) with a mean age 48.85±17.71 years. Comorbid malignant conditions included: Hepatocellular cancer (n= 1), Hodgkin Lymphoma (n= 1), and Thyroid cancer (n=1). Nevertheless, no disease correlation was observed with these malignancies. Mild-moderate Splenomegaly was common (n=7), and the mean spleen size was 11.03± 1.93 cm.
USG showed heterogeneous hypoechoic lesions(n= 11), hyperechoic lesions (n= 1), no vascularity (n= 6), internal vascularity (n= 2), peripheral vascularity (n= 2), and no calcifications (n= 9)(fig 1A, 2A & 2A).
SANT lesions were small and multiple, with the mean size in the largest dimension being 3.56±1.59 cm.
Contrast-enhanced CT scan abdomen showed hypodense lesions (n=5), iso-intense lesions (n=1), no arterial enhancement (n=5), early arterial enhancement (n=1) and progressive heterogeneous enhancement in the portal venous and delayed phase (n=5) (fig 3).
A Gadolinium-enhanced MRI of the abdomen was performed in 12 patients, and one patient was incompatible with the MRI study. It showed T-1 weighted isointense signals in (n=10), hyperintense signals in (n=1), and hypointense signals (n=1). On T2-weighted images, it showed hypointense signals in (n=10), hyperintense in (n=1), and isointense in (n=1). Post-contrast T-1 weighted images showed progressive heterogeneous enhancement (n=10), and washout in the delayed phase (n=2)(fig 4 & fig 5).
The FDG-PET-CT was done in 2 patients, one demonstrated mild uptake and the other one showed avid uptake of radiotracer (fig 1E & 1F).
The diagnosis was established in all cases based on radiological features alone except in one patient in which open splenectomy was performed as the patient was having abdominal pain that was not responding to analgesics. Asymptomatic cases (n=12) were followed-up conservatively with USG abdomen, initially at 3- and 6-month intervals, and later annually if lesions showed the stable size and echotexture Table 1.
Discussion
We did the literature review of articles from PubMed published between 2011-2020. The majority of the articles were Case reports, brief reports, letters to editors, and fewer than five review articles. Total 33 studies were found with imaging features of the patients along with the histopathological diagnosis of Splenic SANT, out od which we analyzed 29 studies with total 31 patients (Table 2).
The imaging features in our study (Table 1) and preiously published literature (Table 3) are quite consistent especially in terms of MRI signals and enhancement pattern.