In a patient with ectopic splenic tissue causing symptomatic mass effect in the pelvis, would you approach radiation differently than you would splenomagaly due to a hematologic malignancy?

Yes, I would approach radiation differently. I would not choose to electively irradiate a patient with a splenunculus/splenunculi.

If the ectopic splenic tissue is large enough to be causing mass effect or is otherwise anatomically situated so as to be causing other issues (e.g. acting as a lead point for bowel torsion or intussusception), it should be surgically excised.

The main indications for splenic irradiation usually pertain to myeloproliferative disorders or malignancies (CLL, PLL, etc). There isn't great data to suggest the extent to which accessory but otherwise normal splenic tissue would respond to RT. To reiterate, one of the main effects here is one of lymphodepletion within the white pulp and splenic reticulo-endothelial sy...