Primary pulmonary rhabdomyosarcoma in childhood: Clinico‐biologic features in two cases with review of the literature—erratum

Abstract

, we reported on two cases of rhabdomyosarcoma (RMS) of the lung arising from normal lung tissue without previous cystic malformations [1]. The histology of these two cases was recently reviewed by the consultants of the International Pleuropulmonary Blastoma Registry. Together with those consultants, we want to amend the original report. After pathologic review, these cases are now classified as Type III pleuropulmonary blastoma (PPB) rather than primary pulmonary RMS. Although these patients received initial complete surgery, postoperative chemotherapy and local radiotherapy, the clinical evolution of the tumor was fatal in both cases. One of these children died from brain metastases, a unique and common complication of PPB [2]. The other child died from respiratory distress after relapse. Microscopically, both tumors contained a rhabdomyosarcomatous element, but both also had blastematous and spindle cell sarcomatous areas. The rhabdomyosarcomatous areas in PPB are identical to embryonal RMS. The presence of high grade blastemal elements, cartilage, spindle cell sarcoma and/or diffuse, marked anaplasia should suggest a diagnosis of PPB for lung masses in children 6 years of age or under [3]. Recently, a similar correction was reported in Pediatric Blood and Cancer and the importance of identifying PPB was stressed [4]. The treatment approaches for PPB and RMS are similar, but unlike RMS, PPB has a propensity for brain metastasis [2]. In addition, PPB is a strikingly familial cancer with genetic implications for others in the immediate and extended families [5]. We appreciate the opportunity to correct the histopathology of these two cases as the importance of the distinction between PPB and RMS is now more evident 12 years after the original report.

Pulmonary and Extrathymic Mediastinal Tumors

“…Rhabdomyosarcomatous areas in PPB are identical to embryonal rhabdomyosarcoma, and cases of PPB have been misdiagnosed as rhabdomyosarcomas arising in a congenital cystic adenomatoid malformation (CCAM) (Pai et al 2007) or in normal lung (Schiavetti et al 2009). Recognition of high grade blastemal elements, cartilage, spindle cell sarcoma, or diffuse-marked anaplasia facilitates the correct diagnosis of PPB in a pediatric lung mass.…”