Cardiac plasma cell granulomas: response to oral steroid treatment.

Plasma cell granulomas are lesions of uncertain histogenesis arising in a variety of locations, most commonly the lung. Treatment for these lesions is complete surgical excision if possible. Unresectable pulmonary lesions respond to oral corticosteroids and radiation therapy. We report the long-term outcome of two unusual pediatric cases of cardiac plasma cell granulomas originating within the right ventricle and posterior aspect of the left ventricle. The limited literature reports advocate surgical resection for this entity, with no discussion of alternative treatment strategies for unresectable lesions. We prospectively evaluated the response to postoperative oral steroid therapy, as complete surgical excision was not possible in either case. Sequential echocardiography demonstrated additional significant reduction in the size of the masses and the patients remain asymptomatic at 9 and 5.5 years follow-up, without evidence of obstruction or recurrence. Oral corticosteroids should be considered as a treatment option for any unresectable plasma cell granuloma.

Pigment epithelium-derived factor (PEDF) in neuroblastoma: a multifunctional mediator of Schwann cell antitumor activity.

Neuroblastoma is notable for its cellular heterogeneity and unpredictable outcome. Tumors are a variable mixture of primitive malignant neuroblasts, more differentiated ganglionic cells, Schwann and endothelial cells. Although often fatal, neuroblastomas can spontaneously regress, possibly due to favorable autocrine and paracrine interactions among these cells. Here, pigment epithelium-derived factor (PEDF), a potent inhibitor of angiogenesis and inducer of neural differentiation, is shown to be produced by ganglionic cells and Schwann cells, but not by more primitive tumor cells. Although undifferentiated neuroblastoma tumor cell secretions were angiogenic primarily due to vascular endothelial growth factor, secretions of Schwann cells were anti-angiogenic due to PEDF. In addition, PEDF was the major factor responsible for Schwann cell's ability to induce tumor cell differentiation in vitro and recombinant PEDF had the same effect in vitro and in vivo. Both the growth and the survival of Schwann cells were enhanced by PEDF. Thus PEDF may serve as a multifunctional antitumor agent in neuroblastomas, inhibiting angiogenesis while promoting the numbers of Schwann cells and differentiated tumor cells that in turn produce PEDF, suggesting that its clinical administration could stimulate a multifaceted antitumor feedback loop with the potential to limit and possibly regress tumor growth.

Isolated colonic neurofibroma manifested by massive lower gastrointestinal bleeding and intussusception.

We report a case of rare solitary neurofibroma of the transverse colon in a patient without neurofibromatosis. The patient was found to have an intussuscepting tumor prolapsing transanally, with massive lower gastrointestinal bleeding. This case represents only the second documented report of an isolated colonic neurofibroma.