Presentation
Abdominal pain. Splenic focal lesions by US.
Patient Data
Enlarged spleen showing multiple variable-sized focal lesions, the largest lesion is seen at its upper pole. The focal lesions show early heterogeneous contrast enhancement with progressive enhancement on delayed imaging resembling hemangioma. Radiological findings were impressive of sclerosing angiomatoid transformation of the spleen.
Right adrenal nodule showing macroscopic fat, impressive of myelolipoma.
Bilateral renal simple cortical cysts.
The previously seen splenic focal lesions elicit low signal at T2 WI and show facilitated diffusion, impressive of their benign nature.
Case Discussion
The patient proceeded to have splenic biopsy of the large upper pole splenic lesion which showed a lesion consisting of variable-sized vascular nodules, surrounded by a rim of fibrous tissue with scattered plasma cells and lymphocytes, the vascular components were composed of variably sized blood vessels with endothelial linning. Nuclear atypia was absent.
Sclerosing angiomatoid nodular transformation (SANT) of the spleen is a recently described, rare, benign vascular lesion.
SANT has a typical radiological pattern. Multiphasic CT shows hypovascular center with an enhancing rim and radiating vascularized tissue penetrating from the periphery toward the center of the lesion. Progressive central enhancement with delayed imaging thought to be the result of contrast penetrating the center of the lesion from the vascular rim "spoke wheel" pattern
On MRI: it typically elicits low signal on T2 WI in contrast to most of the other splenic focal lesions.
On DWI: it shows facilitated diffusion, in contrast to neoplastic focal lesions.
On PET-CT: most cases don't show increased FDG uptake, yet some authors reported mild to moderate increased FDG uptake.