To answer your questions:
1) Without examination, I cannot give an estimate of what the chances are that lymphoma is causing the spleen to be enlarged. However, with the imaging tests you have had done (i.e. CT scans and ultrasounds), this possibility may be less likely.
2) Yes, the CBC (as well as the peripheral smear) is important in the diagnosis of an enlarged spleen. However, there are some diseases that can present with a normal CBC.
3) If it is indeed lymphoma, treatment would depend on the size of the cancer as well as whether it has spread. Without knowing that, it is tough to speculate on the method of treatment.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
Medical Weblog:
kevinmd_b