Mri read retroperitoneal left paraaortic & aortocaval nodes swollen largest measures 1.6 cm. all bloodwork normal. physician clueless of lowerbackpain?

Be glad: Your info suggests that there is no bad (serious / life-threatening / cancerous) source to your back pain. Muscular pain will not show easily on any test. A few swollen lymph nodes might suggest inflammation in area or recent infection or nothing specific. Combination approach is only way to successfully tackle back pain-pt, heat, massage, nsaid, muscle relaxant, stretching. Good luck!