Jackie Garcia of Houston was diagnosed with a tumor weighing nine kilograms. Before that, however, she endured multiple misdiagnoses and unsuccessful weight loss attempts. Over the course of a year, Jackie gained 100 pounds (about 45 kilos), and a CT scan eventually revealed the true cause—a retroperitoneal liposarcoma, a rare form of cancer. The tumor was growing inside her abdomen."I was really into fitness and working out. I would run in the morning or lift weights and then do CrossFit classes and high-intensity training. That was normal for me. I have always been active. I have been running since I was 14," she told PEOPLE. "But in 2017, I was getting bad headaches and feeling really tired. No amount of naps, no amount of sleep could refresh me. After work, I would just go home and go to bed."When she gained weight and went to a doctor she was advised to eat almonds, walk and exercise. Another doctor advised her to try the weight loss drug metformin. She was put on Ozempic in 2022. But she never lost weight."In September 2023, I was working at a new company that had a medical office in the building for employees. I told the doctor, “I feel so sick. Something's wrong with me. Touch my stomach. I feel something in there.” I was basically begging."After this she underwent CT scan and the doctor informed her that she had a large atypical lipoma, associated liposarcoma. "They told me the tumor was pressing on my pelvic floor and encapsulating my ovaries, which is why they couldn't find my ovaries at the ultrasounds. The tumor covered my colon and was on my kidneys. It was pushing up my stomach and my liver, which is why it was hard for me to eat. It was also pressing on my spine," she told the media outlet.She underwent surgery to remove the tumor in December 2023. What is retroperitoneal liposarcoma?“Retroperitoneal” just means the space in your belly behind the lining that holds most of your abdominal organs—like the kidneys, pancreas, and big blood vessels. “Liposarcoma” is a rare type of cancer that starts in fat cells. Put the two together and you get retroperitoneal liposarcoma: a rare cancerous tumor that grows deep in the back of your abdomen. Here’s the problem—it grows quietly. Because it’s tucked way inside, most people don’t notice anything until the tumor gets pretty large. Symptoms can be vague: belly pain, feeling full quickly, constipation, or sometimes even a lump you can feel. By the time it’s spotted, it can already be pressing on organs or blood vessels. It’s uncommon, usually showing up in adults around their 40s to 60s. Doctors aren’t totally sure what triggers it—like many sarcomas, it’s not strongly linked to lifestyle, so it’s not something you can prevent with diet or exercise. The main treatment is surgery—and it’s no small task. Surgeons often have to remove not just the tumor, but sometimes nearby tissue or even organs if the cancer is entangled. In some cases, radiation therapy or newer drug treatments may be added, especially if the tumor can’t be fully removed or if it comes back. Retroperitoneal liposarcoma is rare, sneaky, and serious—but it’s not hopeless. Early detection (often by scans when investigating other issues) and specialized surgical care make a huge difference. If you ever hear this diagnosis, you’ll want a sarcoma specialist on your team right away.