Robert Longo should sue the doctors who told him that the softball-sized tumor in his leg was a muscle tear. The cancer spread to his lungs during the months that Longo tried to convince the doctors that they were wrong. But he cannot sue because Longo's doctors were in the Army and so was he.

Victims of medical malpractice by military doctors could fill a book with their painful experiences, but a series of court rulings known as the Feres Doctrine prohibits military personnel from suing military doctors.

Longo, of Onset, Mass., first felt the pain in his left thigh while he was on duty Dec. 21, 1983. He tolerated it for a few days and then went to an Army aid station and got pain pills. For the next three months, doctor after doctor at the Army hospital in Fort Hood, Tex., told Longo he had a torn muscle.

After watching in horror as the lump grew, Longo asked one doctor if it could be a tumor. "I was told that I was too young to have a tumor," Longo said.

Finally, a doctor sent Longo to a bigger Army hospital at Fort Sam Houston, Tex. "The doctors could not believe what they saw," Longo recalled. They cut out a malignant tumor the size of a softball.

Some members of Congress think that people like Longo should be able to call their doctors to account. Rep. Dan Glickman (D-Kan.) is spearheading the drive to legalize malpractice suits in the military. He says it is unfair that federal prisoners can sue the government, while GIs cannot.

Our associates Melinda Maas and Scott Sleek found several cases in which military personnel claim to have suffered at the hands of military doctors.

Willie Harris of Highland, Calif., injured his knees playing basketball for an Air Force team in 1963. He says military doctors urged him to keep playing and injected cortisone to numb the pain. Today he is disabled. His doctors blame the injections.

Marine Sgt. Lori Jolley entered the Balboa Naval Hospital in Long Beach, Calif., in 1986 for an appendectomy. For months after the surgery, she continued to feel the same symptoms of appendicitis. Eventually she went to the emergency room of a civilian hospital. Doctors there told her that she still had her appendix, but that she was missing an ovary and her fallopian tubes.

E. Christian Gremlich III of Broomall, Pa., became impotent at age 23. But it was 30 years before he discovered that an Army doctor may have been responsible. Military doctors told him he was impotent because of abdominal injuries he received in a car accident. Three years ago, Gremlich found a different story in old medical records.

He had undergone initial surgery after the accident at a civilian hospital, and then the Army insisted that he be moved to a military hospital. Gremlich's records show that the military doctors did not follow the post-operative instructions from the civilian doctors. Gremlich's original physician claims his urethra was not allowed to heal completely, resulting in impotence.

Gremlich is bucking the rules by suing the government for compensation. His case, if successful, could overturn the Feres Doctrine.

Men and women in the military know they may have to risk their lives, but they should not face that risk because of incompetence in a hospital.