Introduction

Pleuropulmonary blastoma (PPB) is a rare malignant neoplasm in adults. It typically presents in young children under the age of 6 years, as a pulmonary or pleural-based tumor with cystic, solid, or combined cystic and solid features (₁). Its primitive, sarcomatous features are analogous to those of other dysembryonic or dysontogenetic tumors, such as Wilms tumor, hepatoblastoma, neuroblastoma, and embryonal rhabdomyosarcoma. (₂). We describe an adult female patient with biphasic PPB in the right lower lung field who underwent complete surgical removal of the tumor, followed by adjuvant chemotherapy and radiotherapy.

Case Report

A 39-year-old female presented at our hospital with two months history of intermittent hemoptysis. Chest posterior anterior and lateral radiographs showed a mass lesion in the right anterior lower lung field about 8x8x9 cm in size (Fig. 1).

Figure 1

Figure 1: Posterior anterior and lateral chest X-rays shows a solid mass at right lower lung field.

Chest computer tomography scan demonstrated a solid mass between the right middle and lower lobes of the lung (Fig. 2).

Figure 2

Figure 2: Preoperative chest computed tomography scan demonstrates a solid mass in the right lower lung field.

Bronchoscopy showed some blood clot in the right middle bronchus. There was no bronchial stenosis and bronchial washing was negative for malignant cells. Ultrasonography of the liver showed a hemangioma 4x3x3 cm at segment 7 and indicated that the mass invaded the diaphragm. Carcinoembryonic antigen (CEA) was 10.9 ng/ml and carbohydrate antigen–199 (CA-199) was 67.7 µ/ml. Under the diagnostic impression of a solid pulmonary mass, we performed a thoracotomy and found the mass located between the right middle and lower lobes of the lung. This mass directly invaded the lung and diaphragm. Wedge resection of the right middle and lower lobes of the lung and partial resection of the diaphragm were performed. The mass, which had a clearly defined margin, was totally removed and measured 9x8x8 cm in size (Fig. 3).

Figure 3

Figure 3: On cut, a sticky-whitish tumor measures 9x8x8 cm in size.

The cut surface was sticky-white. The pathology was reported as biphasic pleuropulmonary blastoma. Histological examination showed both epithelial and mesenchymal components characterized by haphazard glands. These glands were lined by mucin-secreting cells and surrounded by immature spindly mesenchymal cells with scattered islands of chondroid (Fig. 4).

Figure 4

Figure 4: Micrography shows both epithelial and mesenchymal components characterized by haphazard glands. These glands are lined by mucin-secreting cells and surrounded by immature spindly mesenchymal cells (hematoxylin and eosin x 100).

Eight days after operation, the patient was discharged from hospital.

Combined chemotherapy with Gemcitabine (GEMZAR, Lilly, U.S.) 1000 mg every one or two weeks for six times and radiotherapy with 180 Rad for 28 times (total 5040 Rad) were performed. Three months after operation, chest computed tomography scan and ultrasonography of the liver showed no evidence of local recurrence or metastasis. The CEA was 5.3 ng/ml. Two years after the operation, the CEA and CA-199 had decrease to 0.8 ng/ml and 19.4 u/ml. The patient remains well and is being followed-up at out-patients.

Discussion

PPB is a rare malignant neoplasm, especially in adults, for which currently there are no treatment guidelines. It is a rare, aggressive neoplasm that typically occurs in young children under the age of six years (1). We report a female adult who had biphasic PPB in the right lower lung field. She was treated by surgical removal of the tumor, followed by chemotherapy and radiotherapy.

PPB has been classified as type I, II or III on the basis of the cystic versus solid nature of the lesion as well as the histologic appearance. Type I is predominately cystic type, type II is cystic and solid, and type III is predominately solid type (2). In this patient, the histology report was classified as type II.

PPB should be considered when a two-cell pattern consisting of both epithelial and mesenchymal components is observed. The characteristic histopathologic component of PPB includes a biphasic cellular proliferation. One component consists of primitive cells with solitary round hyperchromatic nuclei, at times with distinct nucleoli and scanty cytoplasm, resulting in high nuclear-cytoplasmic ratios. The other major neoplastic element is a spindle-shaped mesenchymal cell (₃).

The biologic behavior of PPB is unpredictable, and for this reason much effort has been expended identifying prognostic factors. The preoperative size of the mass (size <5 cm), its complete excision, and the histologic aspects might be favorable prognostic factors (₄). Because the biologic PPB was unexpected, we performed radiotherapy to prevent local recurrence and chemotherapy to prevent systemic metastasis.

The common presenting symptoms in PPB are dyspnea, tachypnea, chest pain, fatigue, and recurrent pulmonary infection. PPB may show solid and cystic characteristics on plain chest radiographs (₅). The patient presented with the symptom of intermittent hemotysis for two months.

Of clinical importance is the early and differential diagnosis of PPB from other space-occupying lesions of the lung, including epidermoid carcinoma, teratoma, mesothelioma, hamartoma, carcinosarcoma, and benign cystic or solitary lesions (5). Because PPB is very rare in adults, we did not make the right diagnosis before operation until the tumor was removed.

Generally, PPB has an unfavorable clinical outcome: death occurs within 1-2 years after diagnosis. It is an aggressive neoplasm of early childhood and no adequate therapy has been defined to date. After making the diagnosis, the main goal of therapy should be radical surgery, even in patients with microscopic residual disease. Because the response to chemotherapy and local radiotherapy is very poor, the free survival at 2 years from the time of diagnosis is 45% (₆). In this patient, we performed adjuvant chemotherapy with Gemcitabine (GEMZAR, Lilly, U.S.) and radiotherapy (total 5040 Rad) after operation.

The serum level of CEA was 10.9 ng/ml and CA-199 was 67.7 µ/ml. These were all above the normal range. After removal of the tumor, the level of CEA fell to 5.3 µ/ml. One year after operation, the level of CEA was 0.8 ug/ml and CA-199 was 19.4µ/ml. The serum level of CEA and CA-199 may be a good monitor for local recurrence or metastasis of the tumor.

Our case demonstrates that PPB may be present in adults as hemotysis. Surgery, adjuvant radiotherapy and combination chemotherapy should be considered in the treatment of this rare pulmonary neoplasm.

Correspondence to

Dr Talbot, Department of Critical Care Medicine, Changhua Christian Hospital, No.135 Nan Siau street, Changhua, Taiwan, Phone: 886-(4)7238595-5910; Fax: 886-(4)7298682; E-mail: artalbot@ms1.hinet.net