Diffuse intraabdominal desmoplastic small round cell tumor: a ten-year experience.

BACKGROUND: Intraabdominal desmoplastic small round cell tumors (IDSRCT) are rare in children and predominantly affect male adolescents and young adults. We present our experience in the management of five children with diffuse IDSRCT, managed with aggressive chemotherapy, surgery, radiotherapy and peripheral blood stem cell transplantation. MATERIAL AND METHODS: During the last decade five patients, four males and one female (mean age 9.6 years), with diffuse IDSRCT were managed in our department. The main symptoms were abdominal distention, vague abdominal pain, and vomiting. Three patients with inoperable tumor on admission were submitted initially to open biopsy followed by aggressive chemotherapy. Regression of the tumor was followed by a second laparotomy and radical excision of any macroscopically distinguishable masses, followed by chemotherapy. In the remaining two patients a debulking procedure was done initially, followed by chemotherapy. The accurate diagnosis of the disease was established by immunohistochemistry, additionally confirmed in the last two patients by molecular analysis. RESULTS: Three patients who had radical excision of the tumor and adjuvant chemotherapy had recurrence after two to six months. In the remaining two patients, recurrence was evident after two and eighteen months, respectively, following debulking. In addition, one patient with recurrence received radiotherapy and two others underwent peripheral blood stem cell transplantation. All but one patient died within three years from diagnosis. The last patient, who was submitted to a debulking procedure, is still alive eight months after the operation. CONCLUSIONS: Intrabdominal desmoplastic small round cell tumor is a highly aggressive malignancy with a very poor prognosis. Multiagent chemotherapy usually leads initially to a temporary regression of the tumor, but recurrence is the rule. Radical surgical excision, radiotherapy and peripheral blood stem cell transplantation does not seem to improve prognosis significantly. Despite all therapeutic modalities the outcome is dismal and surgical efforts can be considered only as palliative.