No, all abnormal growths are not classified as a cyst but many are. For the most part, they are named depending upon which body structure they are found on or in. For example, a hemangioma is a benign tumor that is composed of dilated blood vessels which may be visible on the skin or deep within some vascular structure. A carbuncle is a deep abscess of the skin that usually comes about from hair follicles. Even common warts are abnormal growths but are not considered cyst's. Polyp's are another example, all are abnormal growths but are classified mainly as to which structure they are involved with. Some are called tumors, some angiomas, some are simply referred to as abnormal growths of tissue. They are also various types of myomas, which involve muscle tissue and lymphomas that involve lymphoid tissue. A common one is a benign lymphoma of the rectum.
A cyst is a growth which may occur anywhere in the body and may contain fluid, gas or be semi-solid. It is enclosed in a capsule. It may be microscopic or can grow quite large. Generally, they are benign, but, sometimes may be associated with cancer or infection. They may sometimes be felt as a lump or can be visualized with X-Ray, MRI or CAT scan testing.
It depends on the structure and the appearance of the growth.
For example, a cyst is a benign tumor, whose aspect is like a closed bag, filled with a liquid or semi-liquid content. The content of the cyst is limited by an own wall. All organs may contain cysts. They can disrupt the functioning of an organ , compressing it, or they may cause aesthetic damages. Generally, they are treated either by needle puncture or by surgical removal.
Also, the abnormal growth could be a nodule. Nodule is a small bulge, well circumscribed, which is occurring in various parts of the body, some chronic diseases being oftenly accompanied by a nodule.