hyperplastic
The general word is cancer.
The term for abnormal development of tissue or organs is Dysplasia
Another name for abnormal swelling starting with 'N' is a Nodule.
Abnormal
Animal tissue
ιστού
An abnormality is something that is not normal in genetics or something that is 'out of this world'.
Neoplasm
biopsy
You're looking for the word elephantitis. (I know it sounds like a joke, but it's not.) Organomegaly is abnormal enlargement of an organ.
The etymological root of oncologist is the greek word Ònkos, meaning 'mass.' An oncologist studies tumors, which are masses of bodily tissue exhibiting abnormal growth.
Care for and encourage the growth or development
A stage of development might also be called a phase of development.