Thorax 1983;38:942-945

Primary pulmonary tumours of neurogenic originGIANCARLO ROVIARO, MARCO MONTORSI, FEDERICO VAROLI, RINO BINDA,ATTILIO CECCHETTO

From Surgical Clinic II, University ofMilan, and the Institute of Pathology, University ofPadua, Italy

AsTRiAcr Primary intrapulmonary neurogenic tumours are extremely rare. In a series of 1664patients with pulmonary neoplasms observed during 1967-80 only four such tumours wereidentified (0.2%). All four patients underwent surgical excision. The histological diagnosis wasbenign neurilemmoma in three cases and malignant schwannoma in the fourth. The patients withneurilemmoma are alive and well four to 12 years after surgery, but the patient with malignantschwannoma died from metastatic spread of the tumour four months after surgery. No associa-tion with von Recklinghausen's disease was observed. Macroscopic and microscopic featuresgenerally lead to a correct diagnosis in benign types, but the histological diagnosis of malignantschwannoma may present some difficulties and requires the establishment of a definite origin in anervous structure, identification of benign neurofibroma in different areas of the same tumour,and a high density of cells with appreciable pleomorphism, with mitosis and atypia. Benigntumours carry a good prognosis with little tendency to recur, but malignant schwannoma has ahigh invasive tendency and is associated with a low survival rate.

Primary pulmonary tumours of neurogenic originare extremely rare' and since the first case wasreported by Rubin and Aronson in 19402 only 50cases have been described in published reports. Tenof these were classified as malignant. Review of thereports excluded some of these cases because ofinadequate histological evidence.34From March 1967 to December 1980 1664

patients with pulmonary neoplasms were observedat our institute. The vast majority of tumours wereepithelial in origin but four (0.2%) were primaryneurogenic tumours, of which one was malignant. Inthis paper we present the clinical and pathologicaldetails of these patients and review the reports thathave been published.

Case reports

CASE 1A man of 45 presented with a symptomless, roundedopacity in the posterior segment of the left lowerlobe. Bronchoscopy showed normal airways, apartfrom reduced mobility of a segmental bronchus ofthe left lower lobe. Left lower lobectomy was per-

Address for reprint requests: Dr Giancarlo Roviaro, ClinicaChirurgica II, Ospedale San Paolo, Via A di Rudini 8, 20142Milan, Italy.

Accepted 28 July 1983

formed. The excised lobe contained a 4 x 5 cm grey-ish white, well encapsulated tumour, surrounded bynormal parenchymal tissue. Histological examina-tion showed an Antoni A type pulmonaryneurilemmoma. The patient was discharged after anuneventful postoperative period and is well and freefrom symptoms 12 years after surgery.

CASE 2A woman of 47, a heavy smoker, had been treatedat the age of 17 for tuberculosis of the left upperlobe by therapeutic pneumothorax. At the age of 46she had a haemoptysis and a chest radiographshowed a shadow in the medial part of the left lowerlobe. Bronchoscopy showed partial stenosis of theanteromedial segmental bronchus of the left lowerlobe and diffuse chronic bronchitis. A left lowerlobectomy was performed. The excised specimencontained an encapsulated, yellowish mass measur-ing 8 x 10 cm, which compressed the adjacent pul-monary parenchyma (fig 1). Histological examina-tion showed an Antoni A type neurilemmoma. Thepostoperative period was uneventful and the patientis alive and well seven years after surgery.

CASE 3A man of 50, who had been treated for tuberculosisof the left upper lobe at the age of 19, had a chestradiograph taken during a medical examination that

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Primary pulmonary tumours of neurogenic origin* .S .... :

Fig Case 2: Macroscopic appearance ofthe tumour,

diagnosed as a neurilemmoma, Antoni A type.

showed a round mass affecting the lower aspect ofthe left hilum. Bronchoscopy showed compressionand partial stenosis of the left lower bronchus a fewmillimetres from its origin. The apical segmentalbranch of the lower lobe bronchus was not visible.The patient underwent a left lower lobectomy. Thespecimen contained an encapsulated, greyish whitemass measuring 6 x 7 cm, firmly adherent to but notinfiltrating the inferior pulmonary vein and lowerlobe bronchus. On the cut surface extensive areas ofhaemorrhage and necrosis were present. Histologi-cal examination showed an Antoni B typeneurilemmoma. The patient made a good recoveryand when last seen, four years after surgery, was

well and free from symptoms.

CASE 4

A man of 27 had always enjoyed good health untilhe suddenly developed a fever, anorexia, weakness,

Fig 2 Case 4: Chest radiograph showing a polycyclic, welldefined mass situated in the anterior planes ofthe lowerthird ofthe right lung, extending medially towards thepulmonary hilum and mediastinum.

and retrosternal pain. All laboratory tests gave nor-mal results except for the erythrocyte sedimentationrate (ESR), which was 80 mm in one hour. A chestradiograph showed a nodular, well defined masssituated in the anterior lower third of the right lung(fig 2), extending medially toward the pulmonaryhilum and mediastinum. Bronchoscopy showeduniform congestion of the bronchus intermedius andthe middle and lower lobe bronchi and extrinsicupward displacement of the middle lobe bronchus.A soft mass filling the middle lobe and the anteriorsegments of the lower lobe was found atthoracotomy. Enlarged soft, bluish red hilar andmediastinal nodes were also present. The middleand lower lobes and mediastinal lymph nodes wereexcised. The mass measured 6 x 11 cm and wasgreyish, with extensive areas of haemorrhage andnecrosis on its cut surface. Adjacent to the middlelobe it was smooth and well encapsulated, whereasclose to the lower lobe it was rough, friable, andgreyish pink, with cystic and haemorrhagic areas.Histologically the tumour consisted of immaturefusiform cells arranged in sheets and cords. Mitoticfigures were frequent and cell borders indistinct (fig3). In another area adjacent to the middle lobe thecells tended to form fascicles with a reticulin patternresembling that of a neurofibroma. The definitivehistological diagnosis was malignant schwannoma.Although the postoperative course was unevent-

ful, some weeks after discharge progressive weak-ness, weight loss, and caval obstruction occurred.Despite chemotherapy and radiotherapy the patientdied four months after surgery.

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Fig 3 Case 4: Microscopic appearance ofmalignantschwannoma: (a) x 75; (b) x 290.

Discussion

Primary intrathoracic neurogenic tumours can origi-nate anywhere in the thorax, but are most frequentlyfound in the posterior mediastinum in the costover-tebral angle.5 Intraparenchymal nerve tumoursderiving from nerve fibres associated with the bron-chial tree are exceedingly rare and in our series of1664 pulmonary tumours they account for only0.2%.Askanazy6 first reported a neurofibroma of the

bronchus associated with generalised neuro-

fibromatosis in 1914. The first case to be describedin detail was published by Rubin and Aronson in

1940.2 Bartley and Arean4 in 1965 found that only32 of the cases reported up to that time were

genuine pulmonary neurogenic tumours. Oosterwijkand Swierenga7 reviewed the published reportsagain in 1970 and added three cases of their own.

Characteristically, primary benign intrapulmo-

Roviaro, Montorsi, Varoli, Binda, Cecchetto

nary neoplasms are asymptomatic, most being dis-covered during routine radiography. Of the threecases we observed, two presented in this way andone patient had an episode of haemoptysis, whichled to radiological investigation. Symptomsdescribed in the published reports are usually mild,consisting of dry cough and some pleuritic pain,48 9

but Bartley reported a typical Pierre-Marie syn-drome with joint pain and stiffness, which disap-peared after removal of the tumour.The symptoms of malignant lesions are similar to

those of the more common carcinoma of the lungand include anorexia, weight loss, and fever or localsymptoms such as thoracic pain, recurrent cough,and haemoptysis. In our fourth patient fever,malaise, anorexia, retrosternal pain, and the highESR, with radiological evidence of a pulmonarymass, suggested a malignant lesion. In both malig-nant and benign tumours radiological and clinicalfeatures are non-specific and a correct diagnosis isusually made only after surgical exploration.Because of the position of these intrapulmonarytumours, resection of the lung tissue in which itoccurs is always indicated.

Grossly benign neoplasms are encapsulated,sometimes lobulated masses of varied dimensionswell demarcated from the surrounding tissue. Whencut they are yellowish owing to the mucin and lipidcontent, firm, and solid. Multilocular cysticstructures may also be seen. Sometimes the tumourpresents as a mass bulging into the bronchial lumenor raising the bronchial mucosa, which may beulcerated.4

Malignant neurogenic tumours are usually largerthan the benign variety. Although distinct from thesurrounding pulmonary parenchyma, they are neverencapsulated. Their cut surfaces vary from grey toyellow, with areas of necrosis, haemorrhage, andcystic degeneration. Primary intrapulmonaryneurogenic tumours may be divided histologicallyinto neurofibroma and neurilemmoma; neurogenicsarcoma and malignant schwannoma are the malig-nant equivalents. Histological diagnosis is generallyeasy in the case of neurilemmoma andneurofibroma, but not always in the case of malig-nant schwannoma, which should be carefully dif-ferentiated from other mesenchymal tumours suchas fibrosarcoma and spindle cell anaplastic car-cinoma.The tumour from the fourth patient meets the

criteria for a neurogenic tumour as defined by Wil-lis.'0 A benign tumour (neurofibroma) could bemacroscopically and microscopically recognised inan area adjacent to the middle lobe, whereas thecapsule was absent in other parts of the tumour,strongly suggesting a malignant schwannoma.

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Primary pulmonary tumours of neurogenic origin

The association between primary neurogenicpulmonary tumours and von Recklinghausen's dis-ease is well known. This syndrome, which is basi-cally due to a defect in the development of Schwanncells, is characterised by the presence of multipleneurofibromas in the skin and internal organs. Ack-erman and Taylor" maintain that in such cases theproportion of malignant neurofibromas is very high,whereas others maintain that malignant mediastinaltumours are most likely to be malignant schwan-nomas.'2 Schwannomas were reported by Stout'3 toaccount for 18%. There was no evidence of vonRecklinghausen's disease in our patients.

In patients without von Recklinghausen's diseasethe prognosis of benign neurogenic tumours is goodand there were no recurrences in the publishedcases. Our three patients are still alive and well fourto 12 years after surgery. Malignant schwannoma,on the other hand, tends to recur and the survivalrate is low. Although Neilson reported a malignantschwannoma in a 35 year old man who is still alivetwo years after surgery, death generally superveneswithin a few weeks'4 and our patient died fourmonths after operation from metastatic spread.

References

' Schield TW. General thoracic surgery. Philadelphia: Lea

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and Febiger, 1972;11:846-58.2 Rubin EH, Aronson W. Primary neurofibroma of the

lung. Am Rev Tuberc 1940;41:801-5.Neilson DB. Primary intrapulmonary neurogenic

sarcoma. J Pathol Bacteriol 1958;76:419-30.4 Bartley TD, Arean VM. Intrapulmonary neurogenic

tumors. J Thorac Cardiovasc Surg 1965;50:114-23.Ingels GW, Cambell DC, Giampietro AM, Kozub RE,

Bentlage CH. Malignant schwannoma of the medias-tinum. Cancer 1971;27:1190-3.

6 Askanazy M. Cited by Neilson.3Oosterwijk AM, Swierenga J. Quelques cas de tumeurs

neurogenes exceptionelles siegeant dans la cavitethoracique. Poumon Coeur 1970;26:571-88.

8 Breton A, Gaudier B, Delacroix R, Dupont A, Poingt 0.Neurinomes intra-pulmonaires primitifs. A propos dedeux observations. Arch Franc Pediat 1961;18:26-40.

9 Soliani F. Neurinomi primitivi intrapolmonari. Policlin-ico (Sez Prat) 1959;66:51-55.

10 Willis RA. Pathology of tumors. 2nd ed. London: But-terworth, 1953:644-55.

"Ackerman LV, Taylor H. Neurogenous tumors withinthe thorax: a clinicopathological evaluation of 48cases. Cancer 1951;4:669-91.

12 Le Brigand H. Le pronostic des tumeurs neurogenesendothoracique de la maladie de Recklinghausen.Ann Chir Thorac Cardiovasc 1977:16-20.

3 Stout AP. The malignant tumors of the peripheralnerves. Am J Cancer 1935;25:36-41.

14 Weitzner S. Adjacent malignant schwannoma andneurofibroma -of intrathoracic vagus. Am Surg1976;42:866-70.

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