Treatment of Pseudotumors With Nonsteroidal Antiinflammatory Drugs By Wendy Su, Albert Ko, Theodore X. O’Connell, and Harry Applebaum Los Angeles, California
Large inflammatory pseudotumors (IPT) traditionally are managed with extensive surgical resection. This approach, which often is associated with significant morbidity, has been deemed necessary because of the uncertainty of diagnosis, symptomatology, and involvement of vital structures. Also, there is a lack of other reliable therapy for this clinically aggressive yet histologically benign disease characterized by an overreactive inflammatory response. The authors treated 2 cases of abdominal IPT with nonsteroidal antiinflammatory drug (NSAID) with successful results.
After a diagnosis of IPT on tumor biopsy, an NSAID trial can confirm the diagnosis and treat the disease by causing tumor shrinkage and eventual resolution. Excision remains indicated in easily resectable tumors and in nonresponders to NSAID therapy. J Pediatr Surg 35:1635-1637. Copyright © 2000 by W.B. Saunders Company.
times a day, was initiated. Subsequent CT scans showed tumor shrinkage with eventual complete regression by 2 months (Fig 2B), when treatment was terminated. He is now disease free at 6 months.
NFLAMMATORY PSEUDOTUMOR (IPT) is a rare childhood condition characterized by the appearance of a mass that resembles a true neoplasm both clinically and on imaging studies. These seemingly aggressive lesions often pose a diagnostic and treatment dilemma.1,2 Almost all the patients have been treated with radical surgical resection because of the uncertainty of diagnosis, fear of disease progression, and the lack of alternative treatment options.1 We evaluated an alternative treatment plan utilizing nonsteroidal antiinflammatory drugs (NSAID), along with physical examination and imaging surveillance, to confirm the diagnosis and to provide the definitive therapy for large abdominal IPT.3 CASE REPORTS
Case 1 A 6-year-old girl had a 1-year history of intermittent abdominal pain. Computed tomography (CT) scan showed a large pelvic mass suggestive of a sarcoma. The mass measured 3 ⫻ 6 ⫻ 8 cm, with ipsilateral hydroureter and hydronephrosis (Fig 1A and B). The patient underwent exploratory laparotomy with incisional biopsy. Pathologic evaluation showed findings consistent with IPT. Treatment was initiated with naproxen, 25 mg orally 3 times a day. Improvement in symptoms and tumor shrinkage were evident within several weeks on physical examination and serial CT scans. Complete resolution of the hydronephrosis and disappearance of the mass was noted on CT scan at 4 months (Fig 1C and D), at which time the treatment was terminated. She is disease free at 2 years.
Case 2 A 14-year-old boy presented with a 2-week history of abdominal and right flank pain, fever, vomiting, and anorexia. He underwent abdominal exploration for presumed appendicitis. Intraoperatively, a 9- ⫻ 5-cm mass was found that was thought to arise from the right upper quadrant colonic mesentery (Fig 2A). The appendix was not located. Needle core biopsy specimens were obtained that showed IPT on pathologic examination. Treatment with ibuprofen, 600 mg orally 4
INDEX WORDS: Inflammatory pseudotumor, nonsteroidal antiinflammatory drug, inflammatory myofibroblastic tumor.
IPT is characterized by the benign proliferation of myofibroblasts and inflammatory infiltrate with a resultant mass.4-6 It often is difficult to differentiate IPT from a true malignancy because of the symptomatology, physical examination, and imaging findings.7 Clinically, patients with IPT can present with fever, leukocytosis, anemia, abdominal mass, and pain.1,2,4-7 The radiolographic and operative findings of IPT resemble a true malignancy, because often it shows adherence to or invasion of neighboring tissues despite its benign histologic appearance.1,4,8 The diagnosis and treatment of IPT has thus been problematic. Even if the biopsy of the mass shows IPT, there still is a concern regarding the adequacy of the biopsy, because only the inflammatory changes surrounding a cancer may have been sampled. These fears often lead to an aggressive surgical approach as the initial treatment of choice. This frequently involves extensive dissection and resection of vital organs with accompanying morbidity.4,8 Several deaths have From the Department of Surgery, Kaiser Permanente Medical Center, Los Angeles, CA. Presented at the 33rd Annual Meeting of the Pacific Association of Pediatric Surgeons, Las Vegas, Nevada, May 15-19, 2000. Address reprint requests to Harry Applebaum, MD, Department of Surgery, Kaiser Permanente Medical Center, 4747 Sunset Blvd, Los Angeles, CA 90029. Copyright © 2000 by W.B. Saunders Company 0022-3468/00/3511-0026$03.00/0 doi:10.1053/jpsu.2000.18340
Journal of Pediatric Surgery, Vol 35, No 11 (November), 2000: pp 1635-1637
SU ET AL
Fig 1. (A) Case 1, a 6-year-old girl with large pelvic mass (arrows). (B) Right hydronephrosis secondary to tumor obstruction (arrow). (C) CT scan 4 months into treatment shows complete tumor regression. (D) Resolution of hydronephrosis (arrow).
been reported as a result of over-zealous surgical attempts to treat this benign disease.4 Although poorly understood, the etiology of IPT seems to relate closely to an altered immune response to
injury.5,7,8 Infection, trauma, previous abdominal surgery, radiotherapy, chemotherapy, and steroid use all have been thought to play a role in the pathogenesis of the heightened inflammatory reaction.1,2,5 It therefore
Fig 2. (A) Case 2, a 14-year-old boy with mass adjacent to the liver (arrows). (B) Tumor resolution after 2 months of treatment.
seemed logical to treat this disease with an antiinflammatory agent. This approach was first suggested by Hakozaki et al,3 who successfully treated a hepatic IPT with NSAID in an adult with subsequent tumor resolution. We adopted this concept and treated 2 children with biosy-proven IPT with NSAID. Both tumors resolved within 2 to 4 months, without any need for a potentially extensive operation. For easily resectable tumors, surgery remains the initial treatment of choice.1,8 However, in cases in which the mass encroaches on or invades important structures, radical surgical procedures should be avoided.2,4,7,8 If the surgeon is reasonably certain of the adequacy of the biopsied specimen, a trial of NSAID treatment may both confirm the diagnosis and treat the tumor successfully.3 Our limited experience indicates that several different types of NSAID are equally efficacious. We suggest that a trial of NSAID be initiated, along with bimonthly physical examinations and monthly CT scans. Tumor shrinkage and improvement of symptomalogy will likely be evident within several weeks of treatment initiation. The protocol is continued until the tumor completely resolves. No chemotherapy, radiation, or antibiotic should be administered concurrently, to avoid confusion regarding the diagnosis.2,4 However, increasing tumor size or worsening symptoms would indicate either a nonresponder to NSAID therapy, or a potential malig-
nancy. In this situation, further workup and an alternative treatment plan would be necessary. The use of NSAID provides a new insight into the diagnosis of IPT and also may be the only treatment required. It should be considered as the initial intervention in the management of this disease.
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