aspiration pneumonia
"I had what a couple of doctors believed to be a necrotizing abscess in my pleural cavity, possibly as a result of the severe pneumonia I was suffering. After 3 days in hospital on strong IV antibiotics and fluids, my vital signs were perfect, but I was still coughing and exhausted. 

An Infectious Disease specialist came to see me after the pulmonary specialist and a surgeon came to tell me their (differing) takes on my diagnosis, and he believed the abscess was actually aspiration pneumonia. He disconnected my IV antibiotics, prescribed Clindamycin in pill form, and sent me home. Sure enough, as promised, within 2 weeks, the "abscess" had completely disappeared from my x-rays without any invasive procedure."