The Amazing Colossal Man (1957)
The Amazing Colossal Man is a 1957 black-and-white science fiction film, directed by Bert I. Gordon and starring Glenn Langan. The film revolves around a man who grows to over 60 feet tall as the result of an atomic accident. It is an uncredited adaptation of the 1928 Homer Eon Flint short novel The Nth Man.
More at Wikipedia.