A RARE SARCOMA

A huge tumor removed from the abdomen of a man who was unaware that there was anything untoward has turned out to be an extraordinary case. The tumor was not only much larger than usual, it was a liposarcoma but contained some elements of bone and cartilage, and had characteristics of osteosarcoma and chondrosarcoma.

"It's a very unusual case," said Joseph Raccuia, MD, clinical assistant professor in the Department of Surgery at NYU Langone Medical Center in New York City. He has been working with sarcomas for 17 years and specializes in liposarcomas, seeing about 5 to 10 cases a year, but has never come across anything like this before.

"Generally speaking, lipomas are fat tissue that has gone crazy...and sometimes the tissue looks almost like normal fat tissue, but this was bizarre," he toldMedscape Medical News. This tumor with its elements of osteosarcoma within a liposarcoma is "an extremely rare bird," he said.

The size was also extraordinary. In his experience, Dr. Raccuia said that the average size of a lipoma is 12.5 cm, while this one was 27.0 cm, and it weighed 20 lbs (9 kg).Amazingly, the patient was unaware that it was growing inside him, and there were no outward signs; he is a tall and rather thin man, and had no obvious abdominal distention. "It was a retroperitoneal tumor, and believe it or not there is a lot of space in there, and these tumors can be very mobile," Dr. Raccuia commented.

It was only lingering pain after he fell last winter that prompted the patient, a 75-year-old man, to visit his family doctor, who referred him to the medical center, where the tumor was found on a CT scan.

"One thing I can say with almost complete certainty," Dr. Raccuia commented in a statement: "The fall that he took last winter saved his life."

"Scan Didn't Make a Lot of Sense"The scan showed that the tumor took up a large volume within the retroperitoneum — it was larger than the liver. It looked like a retroperitoneal liposarcoma, but there was a debate over whether it was a primary renal tumor, as the kidney was displaced and totally engulfed by the tumor."The scan didn't make a lot of sense," Dr. Raccuia said, "but we all agreed that it needed to be removed. We didn't even biopsy it."

The operation was carried out by Dr. Raccuia, working together with colleague William Huang, MD, assistant professor of urologic oncology at NYU Langone. They determined beforehand that the operation would almost certainly involve removal of the kidney and, in fact, the kidney and the adrenal gland were removed, as well as the spleen, as all were affected by the tumor.

It took about 5 hours, which is about the average time for that sort of tumor, Dr. Raccuia said: these operations can take anything from 3 to 8 to 9 hours.

"It was an amazing procedure, one of the largest and most solid tumors I have ever encountered in my surgical career," Dr. Huang commented in a statement.

"We know that liposarcomas can be quite large and very dense because of their physical composition of fatty tissue and, in some cases, even bone. But what we removed from [the patient] was unprecedented, even for this type of malignancy," he said.

The patient will now be monitored every 3 months for the rest of his life. The first scan after the operation showed no sign of tumor recurrence, and this is often the case with liposarcomas, commented NYU Langone oncologist Gerald Rosen, MD, who specializes in sarcomas.

Dr. Rosen said that the patient "benefited tremendously from Drs. Raccuia's and Huang's aggressive surgical approach, so no postsurgical chemotherapy or radiation is required at this time.... However, we have to keep a watchful eye on [the patient], given his age and what we know about tumor recurrence with this type of cancer."

The fact that the patient was unaware of the tumor is not unusual. "In general, liposarcoma grows silently," notes the Medscape Reference liposarcoma entry. "Most patients with liposarcoma have no symptoms until the tumor is large and impinges on neighboring structures, causing tenderness, pain, or functional disturbances. In the retroperitoneal area, where liposarcoma is detected at a late stage, the tumor may grow to a substantial size, weighing several pounds at the time of diagnosis."