Hello docs, is atypical pneumonia a type of disease?

Yes: The term atypical pneumonia is used when it does not show up on x-rays. It is usually caused by viruses and some bacteria like organisms.

Pneumonia variant: This label is often applied to a form of pneumonia that is triggered by mycoplasma, a different type of germ than the "typical" pneumococcal or viral pneumonia. It's x-ray picture differs and confirmation can be made through blood tests. Most often the x-rays and other findings allow treatment with readily available meds so further studies are unnecessary.