Trader, a 7-year-old male golden retriever, kept losing weight despite a normal appetite. Long story short: Abdominal palpation, radiographs and ultrasound suggested a very large abdominal mass, presumed to be splenic in origin. Trader is a golden, after all. Since thoracic radiographs were normal, Trader’s owners elected surgery. We removed a 14-pound multilobulated ugly-looking mass. It had numerous adhesions to the pancreas, the duodenum, the jejunum and the omentum. A few days after Trader went home, histopathology revealed a leiomyoma, a perfectly benign tumor of the smooth muscle. Collin, a 12-year-old male intact German shepherd, had a large ugly-looking paraprostatic mass. It was as large as his head! Its inner wall was lined with cartilage. It was partially resected, omentalized and biopsied. Histopathology revealed dystrophic ossification of a perfectly benign periprostatic cyst. Lady, a 9-year-old Labrador retriever, appeared lethargic and weak. She was diagnosed with hypoglycemia. What is your differential diagnosis? (See “Differential Diagnosis of Hypoglycemia” at VeterinaryPracticeNews.com/DDHypo.) Palpation and X-rays revealed a large mass in the cranial abdomen. Exploratory confirmed a soft-ball sized mass attached to the pylorus. The mass was excised, and histopathology revealed a leiomyoma. Lady made a full recovery, and is back to normal six months after surgery. Igor, an 11-year-old Borzoi, had difficulty walking and breathing. Abdominal palpation and radiographs revealed a large abdominal mass. Thoracic radiographs were within normal limits. Exploratory laparotomy revealed a 6-pound multilobulated encapsulated ugly-looking mass. It had numerous adhesions to the omentum. Igor went home the next day, feeling great. Histopathology revealed a perfectly benign intra-abdominal lipoma with extensive central necrosis. The mass contained 900 ml of oily fluid. Regis, a 16-year-old male collie mix, suddenly had difficulty getting up. His referring vet palpated a large, firm abdominal mass. X-rays confirmed a large mass. Unlike most owners of a 16-year-old dog, and despite the odds, Regis’ owners elected surgery. The next day, he had surgery to remove a 7-pound splenic mass. One week later, the biopsy came back as benign! Regis’ mass was a perfectly benign hematoma. A softball-sized mass is attached to the pylorus of a 9-year-old Labrador. We could go on … What is the moral of these stories? The mere suggestion of euthanasia based on the simple fact that these masses were “huge” would obviously not have been in the patients’ best interest. Fortunately for these patients, their referring vets were well aware of a little secret of surgery: Size doesn’t matter. Just because a mass is large doesn’t mean that it is malignant. And just because it looks ugly doesn’t mean that it is cancerous. The same concept applies to skin and subcutaneous (SQ) masses. We have all seen giant SQ lipomas, on the chest wall or the caudal thigh, for example. Granted, even though such masses are benign, it would be better for the patient to excise them before they reach gargantuan proportions. Actually, size is not the only reason to remove a skin mass. Other reasons include self-trauma, a sudden increase in size, an open wound from pressure necrosis or external trauma (e.g. rubbing on the ground), and impairment of a bodily function. Elsewhere in the body, a mass could affect the patient’s ability to eat, breathe, defecate or urinate. In such cases, it almost doesn’t matter whether the tumor is benign or malignant. The only realistic way to help the patient is surgical excision, unless chemotherapy and/or radiation therapy are believed to be better options. At the very least, a biopsy or a fine-needle aspirate of any mass should be recommended to the client. How the mass “feels” is irrelevant. We may be convinced that a subcutaneous mass feels like a lipoma, but a mast cell tumor isn’t called “the great imitator” for no reason. If the pathologist suspects or diagnoses cancer, then a serious discussion about surgery should take place with the owner. If the mass is benign, surgery should be planned. And of course, that conversation should be documented in the medical record. Whether a skin mass should be removed remains a never-ending source of controversy for some people. Yet it has been wisely said that “Just watch it” are the deadliest words in vet medicine. An equally dangerous variation is “Keep an eye on it.” So why does it seem that large masses often appear to be benign? Arguably, large, benign masses may have been present for a long time. They may not have robbed the body of important nutrients. They may not have caused any distant side-effects or paraneoplastic symptoms. They may have had plenty of time to metastasize—but never did. These very subjective impressions may suggest that the mass is more likely to be benign. Alas, it is not quite that simple. The exact opposite can be true: Small masses can be benign, and large masses may be cancerous. Indeed, we all have seen tiny lipomas and giant carcinomas. Of course, the timeless surgical principle of “Size doesn’t matter” is not limited to masses. A tiny stone could block a dog’s urethra—a potentially deadly condition. Similarly, a tiny mucous plug could do the same to a cat’s urethra. A tiny herniated disc can paralyze a dog. Tiny misdirected hair on the eyelid can cause a severe corneal ulcer in the case of entropion. You get the idea. So what’s a caring practitioner to do? Bottom line: Size doesn’t matter. Before judging a mass by its cover, it may be wise to aspirate or biopsy it before any irreversible decision is made. <Home> Dr. Phil Zeltzman is a mobile, board-certified surgeon near Allentown, Pa. His website is Dr PhilZeltzman.com.
