British Journal of Radiology (2003) 76, 574-576
© 2003 British Institute of Radiology
doi: 10.1259/bjr/67532842
Pedunculated malignant peripheral nerve-sheath tumour of the diaphragm presenting as recurrent lung infection: ultrasound diagnosis
S-F Ko, MD1,
S-H Ng, MD1,
T-Y Lee, MD1,
P-L Sun, MD1,
S-Y Lee, MD2 and
C-C Hsiao, MD3
Departments of 1 Radiology, 2 Paediatric Surgery and 3 Paediatrics, Chang Gung University, Chang Gung Memorial Hospital at Kaohsiung, Taiwan
Correspondence: Sheung-Fat Ko, MD, Department of Radiology, Chang Gung Memorial Hospital at Kaohsiung, 123 Ta-Pei Road, Niao-Sung Hsiang, Kaohsiung Hsien, 833, Taiwan
 |
Abstract
|
|---|
We report a rare case of malignant peripheral nerve-sheath tumour of the diaphragm in a 12-year-old boy with neurofibromatosis presented clinically and radiographically as recurrent lung infection. Ultrasound revealed a pedunculated diaphragmatic tumour invading the posterior chest wall. This case highlights that this unusual tumour may limit diaphragmatic excursion leading to, and even being masked by, superimposed lung infection. In patients with neurofibromatosis, ultrasound is recommended when chest radiography shows a basal lung opacity.
|
Introduction
|
|---|
Primary neoplasms of the diaphragm are uncommon and are difficult to assess either clinically or radiographically [1–7]. Lipomas and simple cysts are the most common benign masses while fibrosarcoma is the most common malignant tumour [1, 2]. Neurogenic tumours account for about 10% of the reported diaphragmatic tumours [1–3]. Diaphragmatic malignant peripheral nerve-sheath tumour (MPNST) is extremely rare [2–6]. The incidence of MPNST in the general population is 0.001% while the risk is approximately 4600 times higher in patients with neurofibromatosis and 3–13% of them will finally develop MPNST, usually after latent periods of 10–20 years [7]. We report a case of diaphragmatic MPNST in a 12-year-old boy, emphasising that this rare tumour may be encountered in paediatric patients with neurofibromatosis and may easily be masked by superimposed pneumonia.
|
Case report
|
|---|
A 12-year-old boy suffered from 4 episodes of lung infection in 3 months treated in a local clinic and was referred to our hospital with a 4-day history of persistent cough and fever, despite antibiotic treatment for 3 days. A diagnosis of lobar pneumonia with empyema had been made following chest radiographs showing right lower lobe consolidation with a pleural effusion. On admission, physical examination revealed typical findings of neurofibromatosis including multiple café au lait spots on the back (more than 6, 1–3 cm in diameter), freckling in the inguinal regions, and multiple 0.5–1 cm nodules all over the trunk, of which some were biopsy-proved neurofibromas. There was no evidence of finger clubbing. Auscultation revealed decreased but coarse breathing sounds over the right lower chest. Laboratory investigations showed a haemoglobin level of 10.4 g dl-1 and a white blood cell count of 13 x 109 cells l-1 with 75% polymorphonuclear leukocytes. Chest radiographs (Figure 1a
) showed a right basal lung opacity. Thoracentesis produced 750 ml of brownish red fluid and culture yielded gram-positive cocci. Pneumonia with empyema was the initial impression. 4 days later, the patient's fever subsided following appropriate antibiotic treatment. Follow-up chest radiograph revealed a persistent right basal lung opacity and possible rib destruction. Ultrasound (Figure 1b) revealed a heteroechoic pedunculated mass (10 x 9 cm) arising from the right diaphragm with invasion of the right posterior chest wall. Chest CT showed similar findings and confirmed destruction of the right ninth rib (Figure 1c), confirmed at thoracotomy. Total excision of the tumour, resection of the right ninth rib, cuff resection and repair of the right hemidiaphragm were performed. Histopathologic examination revealed storiform-arranged pleomorphic spindle cells with buckled, hyperchromatic nuclei and frequent mitoses. Immunohistochemically, the tumour was negative for S-100, bcL-2, cytokeratin, desmin, actin and CD34, but was positive for epithelial membranous antigen, vimentin, CD56 and Ki-67. There was no significant overexpression of p53. Final diagnosis was high grade MPNST. At the 1-month follow-up, CT revealed rapid local recurrence. Radiotherapy and chemotherapy (cisplatin, etoposide, ifosfamide) were instituted. An osteolytic lesion in the left distal femur was noted 6 months later and an echo-guided biopsy indicated metastatic MPNST.
View larger version (100K):
[in this window]
[in a new window]
|
Figure 1. (a) Chest radiograph shows an opacity in the right lower lung, suggesting pneumonia with empyema. Note destruction of the right ninth rib (arrows) was initially overlooked. (b) Ultrasound demonstrates that a pedunculated tumour (black and white arrows), amidst the pleural effusion, originates from the right hemidiaphragm (small arrows) and extends posteriorly beyond the chest wall. (c) CT reveals a right basal thoracic mass with invasion of the right ninth rib.
|
|
|
Discussion
|
|---|
Malignant neurogenic tumours of the diaphgram are rare and only 5 cases have previously been documented in adults [2–6]. MPNSTs usually affect the head and neck, trunk and extremities. The mean age of MPNST at diagnosis in patients with neurofibromatosis is considerably younger (28.7 years) as compared with those without neurofibromatosis (39.7 years) [7]. To our knowledge, this is the first report of diaphragmatic MPNST in a paediatric patient with neurofibromatosis. The clinical presentations of neurogenic tumours of the diaphragm may be variable, including pleuritic chest pain, cough, dypsnoea and dysphagia. Clubbing of the fingers is common for patients with diaphragmatic neurilemmomas [2]. Our patient revealed no finger clubbing and presented as recurrent lung infections while the tumour was masked by superimposed pneumonia and empyema. We postulate that the recurrent infections in the right lower hemithorax may be ascribed to hindrance of diaphragmatic excursion by this unusual malignant tumour.
Assessment of diaphragmatic tumours by chest radiograph is difficult [1–6], especially in the presence of superimposed infection, which may obscure the tumour and rib destruction, as seen in this case. CT and MR are helpful for the anatomical delineation of thoracic neurogenic tumours but the CT densities and the MR signal intensities of the masses are non-specific for differentiating between benign and malignant nerve-sheath tumours [8, 9]. On the other hand, associated pleural abnormalities and destruction of adjacent bony structures are clues for the presence of sarcomatous transformation of neurogenic tumours [8–10]. However, routine application of CT or MR imaging for screening lung opacity with clinical presentations of lung infection is of doubtful practicality. Ultrasound has been reported as a useful tool for the evaluation of peripheral lung and pleural lesions and as a guide for needle biopsy or aspiration of parapneumonic effusion [11, 12]. As illustrated in this case, ultrasound can indeed be a helpful tool of basal lung opacity by elucidating the tumour within effusion, delineating the pedunculated tumour origin at the pleural side of the right hemidiaphragm, and showing tumour extension to the chest wall and absence of liver involvement. Such imaging findings facilitated the decision for the surgical resection of the tumour and cuff resection of the diaphragm via the right thoracotomy approach [2]. Tumours arising from the hemidiaphragm may be excised through thoracotomy or laparotomy, but when the abdominal organ is invaded, the laparotomy approach is mandatory [2].
MSPNT does carry a grave prognosis, particularly in the setting of neurofibromatosis with a 5-year survival rate of 16% [7]. Radical excision is the treatment of choice for MPNST and radiation therapy is an alternative for any unresectable portion of the tumour whilst the role of adjuvant chemotherapy remains unsettled [2–7]. In our patient, early local recurrence and bone metastases occurred despite radical surgery. Combined radiotherapy and chemotherapy achieved moderate regression of these lesions and he still remains alive 16 months subsequent to surgery.
In summary, the report documents an unusual case of MSPNT in a 12-year-old boy with neurofibromatosis presenting as recurrent lung infection clinically. In patients with neurofibromatosis, ultrasound may be helpful in revealing a bewildering diaphragmatic lesion that may mimic lung infection on chest radiograph, and allow earlier detection of such unusual tumours.
Received for publication September 25, 2002.
Accepted for publication February 13, 2003.
|
References
|
|---|
- Olafsson G, Rausing A, Holen O. Primary tumors of the diaphragm. Chest 1971;59:568–70.[Abstract/Free Full Text]
- McClenathan JH, Okada F. Primary neurilemmoma of the diaphragm. Ann Thorac Surg 1989;48:126–8.[Abstract]
- Sampson PC, Childress ME. Primary neurofibrosarcoma of the diaphragm: report of two cases. J Thorac Surg 1950;20:901–10.
- Doyle T. Left basal opacity for diagnosis. Chest 1983;84:199–200.[Free Full Text]
- Koyama S, Araki M, Suzuki K, Fukutomi H, Maruyama T, Mun Y, et al. Primary diaphragmatic schwannomas with a typical target appearance: correlation of CT and MR imaging and histologic findings. J Gastroenterol 1996;31:268–72.[CrossRef][Medline]
- Lee JT, Lee JD, Choe KO, Yang WI. Giant malignant schwannomas of the diaphragm: CT and ultrasound findings. Yonsei Med J 1991;32:82–6.[Medline]
- Ducatman BS, Scheithauer BW, Piepgraas DG, Reiman HM, Ilstrup DM. Malignant peripheral nerve sheath tumors: a clinicopathologic study of 120 cases. Cancer 1986;57:2006–21.[CrossRef][Medline]
- Ko SF, Lee TY, Lin JW, Ng SH, Chen WJ, Hsieh MJ, et al. Thoracic neurilemmomas: an analysis of CT findings in thirty six patients. J Thorac Imaging 1998;13:21–6.[Medline]
- Ko SF, Ng SH, Lee YT, Lin J-W, Chen WJ, Hsieh MJ, et al. MR imaging of thoracic neurilemmomas. Magn Reson Imaging 1997;15:525–33.[CrossRef][Medline]
- Levine E, Huntrakoon M, Wetzel LH. Malignant nerve sheath neoplasms in neurobromatosis: distinction from benign tumors by using imaging techniques. AJR Am J Roentgenol 1987;149:1059–64.[Abstract/Free Full Text]
- Yang PC, Luk KT, Chang DB, Wu HD, Yu CJ, Kuo SH. Value of sonography in determining the nature of pleural effusion: analysis of 320 cases. AJR Am J Roentgenol 1992;159:29–33.[Abstract/Free Full Text]
- Yang PC. Ultrasound-guided transthoracic biopsy of peripheral lung, pleural and chest-wall lesions. J Thorac Imaging 1997;12:272–84.[Medline]
Top
Abstract
Introduction
