Causes for pain middle to low back on l side wraps around to the side, constant but worse when sitting. 8/18 spleen measured 14cm? i can feel a lump

Back pain: Low back pain can be from muscle spasm, herniated disc, osteoarthritis etc..., see a doctor to evaluate the 'lump'.

Flank pain : Constant pain in mid to low back area wrapping around to the side with enlarged spleen is of concern . It could reflect pathology related to spine, left kidney , pancreas , systemic , hematopoietic , lymphatic , reticulo endothelial system, GI pathology , abdominal aorta etc to name some. Consult an experienced internist for further thorough evaluation right away.

?spleen: Your spleen size was measured during the ct scan? If it is enlarged it can mean liver cirrhosis or a hematologic problem or even an infection like mono. Pain as you describe could be from a damaged nerve, as with a herniated disc or shingles although there is usually a rash with shingles. It could possibly be related to your kidney. Any lumps need to be evaluated by your doctor.

Abdominal pain: Your spleen is mildly enlarged but because it has to be enlarged much more to give pain. This kind of pain could be from kidney stones sometimes even from back sprain please see a doctor about this.