We will describe a case of a patient diagnosed with a rare identity of a benign lesion, “reactive nodular fibrous pseudotumor” (RNFP). It is a tumor which preoperatively can present as a malignant tumor and is only reported in 19 cases. According to the very limited amount of information on this tumor in the literature it is mostly seen after trauma or intraperitoneal inflammation. Our case is the second one of RNFP associated with endometriosis, which is a frequently seen intraperitoneal inflammation process in women. Knowledge that these large pseudotumoral lesions can occur is important to direct the management of these patients. 1. Introduction A multitude of tumors can occur in the peritoneal cavity. Correct diagnosis is of paramount importance for proper treatment. We recently observed a patient with an intra-abdominal mass, diagnosed histopathologically as “reactive nodular fibrous pseudotumor” (RNFP). This is a benign lesion, often mimicking a malignant tumor preoperatively. The pathogenesis might be related to intraperitoneal “trauma” such as endometriosis. It is previously reported in only 19 cases. 2. A Case Report A 45-year-old woman was hospitalized in another hospital, because of intractable menometrorrhagia, pain, and gradual abdominal swelling. A vaginal hysterectomy was planned and performed but shortly had to be stopped because of bleeding. During the procedure intraperitoneal lesions were seen and biopsied. Pathology shows no signs of malignancy. Afterwards the patient was sent to our hospital for further diagnosis. Her medical history mentioned no other abdominal surgery, migraine headaches, or other major incidents. Her obstetrical history recorded an uncomplicated vaginal delivery. Clinical examination showed no particularities. Biochemically we found no abnormalities and serum CA125 levels were normal. Gynecological ultrasound (Figure 1) demonstrated not only diffuse uterine adenomyosis and myomas, but also multiple solid masses in the Douglas pouch, attached to the left ovary and rectosigmoid but without invasion of its muscular wall. MRI (Figures 2, 3, and 4) and CT (Figure 5) confirmed the presence of solid and strongly hypovascular masses in the pouch of Douglas. A similar smaller lesion was present at the caudal border of the transverse colon. The very low signal intensity on T1- and T2-weighted MR images was very suggestive for fibrotic tissue. On imaging the diagnosis of disseminated intraperitoneal leiomyomatosis was suggested, but other fibrous tumoral lesions or malignancy could not be excluded. Figure 1: Ultrasound:
References
[1]
R. K. Yantiss, G. P. Nielsen, G. Y. Lauwers, and A. E. Rosenberg, “Reactive nodular fibrous pseudotumor of the gastrointestinal tract and mesentery: a clinicopathologic study of five cases,” The American Journal of Surgical Pathology, vol. 27, no. 4, pp. 532–540, 2003.
[2]
E. Virgilio, E. Pucci, E. Pilozzi, S. Mongelli, M. Cavallini, and M. Ferri, “Reactive nodular fibrous pseudotumor of the gastrointestinal tract and mesentery giving multiple hepatic deposits and associated with colon cancer,” The American Surgeon, vol. 78, no. 5, pp. E262–E264, 2012.
[3]
O. Daum, T. Vanecek, R. Sima et al., “Reactive nodular fibrous pseudotumors of the gastrointestinal tract: report of 8 cases,” International Journal of Surgical Pathology, vol. 12, no. 4, pp. 365–374, 2004.
[4]
J. Berman and T. J. O'Leary, “Gastrointestinal stromal tumor workshop,” Human Pathology, vol. 32, no. 6, pp. 578–582, 2001.
[5]
J. A. Brainard and J. R. Goldblum, “Stromal tumors of the jejunum and ileum: a clinicopathologic study of 39 cases,” The American Journal of Surgical Pathology, vol. 21, no. 4, pp. 407–416, 1997.
[6]
M. Miettinen and J. Lasota, “Gastrointestinal stromal tumors—definition, clinical, histological, immunohistochemical, and molecular genetic features and differential diagnosis,” Virchows Archiv, vol. 438, no. 1, pp. 1–12, 2001.
[7]
A. F. Nascimento, R. Ruiz, J. L. Hornick, and C. D. M. Fletcher, “Calcifying fibrous “pseudotumor”: clinicopathologic study of 15 cases and analysis of its relationship to inflammatory myofibroblastic tumor,” International Journal of Surgical Pathology, vol. 10, no. 3, pp. 189–196, 2002.
[8]
P. B. Clement, “Disease of the peritoneum,” in Blaustein’s Pathology of the Female Genital Tract, R. J. Kurman, Ed., pp. 731–732, Springer, New York, NY, USA, 2002.
[9]
P. B. Clement, R. H. Young, W. Hanna, and R. E. Scully, “Sclerosing peritonitis associated with luteinized thecomas of the ovary: a clinicopathological analysis of six cases,” The American Journal of Surgical Pathology, vol. 18, no. 1, pp. 1–13, 1994.
[10]
D. E. Comings, K. B. Skubi, J. van Eyes, and A. G. Motulsky, “Familial multifocal fibrosclerosis: findings suggesting that retroperitoneal fibrosis, mediastinal fibrosis, sclerosing cholangitis, Riedel's thyroiditis, and pseudotumor of the orbit may be different manifestations of a single disease,” Annals of Internal Medicine, vol. 66, no. 5, pp. 884–892, 1967.
[11]
J. R. Graham, H. I. Suby, P. R. LeCompte, and N. L. Sadowsky, “Fibrotic disorders associated with methysergide therapy for headache,” The New England Journal of Medicine, vol. 274, no. 7, pp. 359–368, 1966.
[12]
W. A. Hawk and J. B. Hazard, “Sclerosing retroperitonitis and sclerosing mediastinitis,” The American Journal of Clinical Pathology, vol. 32, pp. 321–334, 1959.
[13]
E. A. Saglam, A. Usubütün, C. Kart, A. Ayhan, and T. Kü?ükali, “Reactive nodular fibrous pseudotumor involving the pelvic and abdominal cavity: a case report and review of literature,” Virchows Archiv, vol. 447, no. 5, pp. 879–882, 2005.