Unusual survival of an adult with pleuropulmonary blastoma and neurofibromatosis

Abstract

Clinical Summary Chest radiography showed a solid mass encased within a large cystic structure, suspicious for aspergilloma of the left lung. A chest computed tomographic scan revealed a huge multiseptated cystic structure involving the entire major fissure of the left lung, containing a multilobulated soft tissue mass (Figure 1), and measuring approximately 10 20 cm. The mass and cysts were completely excised through a left thoracotomy. The specimen weighed 85 g in aggregate and consisted of thin-walled cysts, imparting a botryoid (ie, grape-like) appearance, with minor solid components (Figure 2, A ). Microscopically, small immature tumor cells with ovoid to spindle-shaped nuclei were set in a myxoid stroma. Cellularity was highest in the so-called cambium layer just beneath the attenuated cyst lining (Figure 2, B). Tumor cells were positive for desmin and other muscle markers by immunohistochemistry. A diagnosis of pleuropulmonary blastoma (PPB) type II was made. The patient’s postoperative course was uneventful. Retrospective pathologic examination of the blebectomy specimen obtained 2 years earlier revealed subtle histologic features suggestive of PPB type I. The patient received a multidrug regimen of 11 cycles of chemotherapy, consisting of vincristine, actinomycin, and cyclophosphamide during the first phase, and doxorubicin (Adriamycin; Bedford Laboratories, Bedford, Ohio), cisplatin, and doxorubicin during the second phase. Follow-up computed tomography scans of the chest, abdomen, and pelvis revealed no evidence of recurrence or metastasis at 24 months. The patient is currently asymptomatic with good weight gain and normal physical strength. Discussion This case report demonstrates the cardinal clinical and pathologic features of PPB, a highly aggressive childhood malignancy, in an adult. These tumors present almost exclusively in the first decade of life. 1 To our knowledge, 4 adult patients have been reported in the literature, with only 1 survivor at 29 months, after radiation therapy of a nonresectable PPB. 2 It is now recognized that 25% of PPB cases occur in a familial setting with other tumors of childhood, such as cystic nephroma, rhabdomyosarcoma, and synovial sarcoma. 3 There are no reports in the literature of any case of PPB associated with neurofibromatosis. Clinical presentation of these rare tumors may vary from ruptured lung blebs, as in our patient, or space-occupying masses resembling a mediastinal teratoma 4 to more subtle manifestations of chest pathology or systemic disease. The clinical and radiographic differential diagnosis includes fungal lesions, congenital cystic adenomatoid malformation, bronchogenic cyst, and postinfectious pneumatocele. Three pathologic types of PPB have been described: Type I is purely cystic and may present as a congenital lung cyst; type II is a combined cystic and solid tumor; and type III is solid and can be accompanied by hemorrhage and necrosis. 2