Jen Arnold, the star of TLC's "The Little Couple," has revealed she is battling a rare form of cancer. "I have recently been diagnosed with a rare type of cancer and am currently undergoing treatment, including surgery and chemotherapy," Arnold, 39, said in a statement emailed to The Huffington Post. "I am very fortunate as the prognosis is good. While there is never a good time to get news like this, getting it just as we are building our new family is tough in many ways. ... But being surrounded...