Pulmonary cytology

Pulmonary Cytology JOHN R .

McDONALD, m .o .,

From the Section of Surgical Pathology, Mayo Clinic and Mayo Foundation, Rochester, Minn.

finding of whitish pieces aid . In our laboratory the smear method rather than paraffin sections has been utilized because of the ease of preparation and also because more material can be examined by this particular method . Our staining technic is that of hematoxylin and eosin rather than any of the trichrome technics that have been employed by others . The diagnosis of anaplastic cells does not appear to be aided by the use of special stains inasmuch as the nucleus is the structure essential to the diagnosis anyway .

CYTOLOGIC laboratory for the examination

A of pulmonary secretions is a useful and

almost necessary adjunct in a diagnostic center which deals with diseases of the thorax . My colleagues and I have found it of inestimable aid in the diagnosis of obscure carcinoma of the lung . It is unfortunate that cytologic study is such a time-consuming procedure, because if it were not it would be exceedingly useful in the detection of unsuspected pulmonary carcinoma, inasmuch as sputum can be raised from the vast majority of lungs . However, attempts to mechanize the procedure have not proved too successful . As it is now, because of the personnel-time factor involved, it is a costly affair . Most laboratories have utilized technicians to scan the smears of sputum and bronchial secretions and to spot any abnormal cells . This is of inestimable aid in decreasing the time expended by the physician cytologist in examination of the smears of sputum or secretion . It means, of course, that the negative reports are essentially the responsibility of the technician . However, the positive reports become the responsibility of the cytologist. A year's training is necessary in order to make a technician capable of recognizing suspicious-appearing cells in bronchial material . A longer period of training is preferable and certainly leads to increased competency on the part of the technician scanner . The laboratory of pulmonary cytology at the Mayo Clinic has been organized so that sputum and pulmonary secretions or washings are examined. The sputum is collected in bottles which contain 95 per cent ethyl alcohol . This bottle is given to the patient with instructions to produce sputum from the lungs and not to put saliva into the bottle . A twenty-four-hour specimen is not necessary . Five smears are made at random from the sputum . Selection of the grossly bloody portions of sputum apparently does not increase the incidence of positivity of the smears for cancers, nor does the American Journal of Surgery, Votume 89, Ma rch, 1955

Rochester, Ahnnesota

RESULTS

During the six years of operation of our laboratory for pulmonary cytology we have reported positive findings in i,6oo cases. In 76 per cent of these cases the positive diagnosis of malignant cells was made from examination of sputum, while in 39 per cent it was made from bronchial secretions . Obviously study of both sputum and bronchial secretions gave positive results in some cases . In 1 .7 per cent of this entire group the diagnoses have been considered to be false positive. The results of' cytologic examinations in our laboratory have been reported either as positive or negative on a purely objective basis . The history has not been available during the examination of the suspected material . This seems exceedingly wise to us . In certain cases in which the diagnosis was considered at first to be falsely positive, the patient has later been proved to have cancer of the lung . Other patients are still awaiting an answer . Temporarily these results have been called false positives . The following case illustrates this : The patient, a sixty-three year old man, stated on admission to the clinic that he had been coughing and wheezing for six months . Wheezes were expiratory and inspiratory and bilateral . A roentgenogram of the chest showed fibrous and calcified lesions in apices of both lungs which were thought to be due to ancient tuberculosis . Two bronchoscopic examinations were negative but malignant cells were found

462

Pulmonary

Cytology

Fr( ; . i . A clump of signs of cancer .

annpiastic-appearing cells in bronchial sterabm

Pie . 2 . A clump of

cancer cells is shown in

This patient

has not shown any clinical

sputum .

in bronchial secretions from both the right and left bronchi on two occasions . (Fig . i .) Sputum was consistently negative for malignant cells . Re-examination one and a half years later showed no change in the status and no development of symptoms suggesting bronchogenic carcinoma . In this case the result must be considered false positive although the cells are very suggestive of malignant cells . It is very difficult to determine what the false-negative error is in such a series of cases . The false negative error probably is between 3o and 33 per cent in our cases . If this percentage is lowered much, the false positive error increases . In spite of this high degree of false negativity for bronchogenic carcinoma, the procedure is exceedingly valuable .

and if no such communication is present, the sputum will not be positive . 3 . Examination of sputum in the presence of a metastatic lesion is definitely valuable in the diagnosis of malignant disease and- it frequently may give the first positive evidence that a metastatic lesion exists . 4 . In cases of alveolar cell tumor cytologic examinations usually give positive findings . The more anaplastic the cell type in this disease, the more readily the tumor cells are recognized in sputum and bronchial secretions . Frequently the cells are found in clumps which have broken off . The main usefulness of cytologic examination of pulmonary secretions lies in the diagnosis of bronchogenic carcinoma . The following case illustrates this : The patient, a sixty year old man, had been a heavy cigarette smoker for many years but his cough had become worse in the last six weeks before admission . There had been no hemoptysis . Physical examination gave negative results . A routine roentgenogram of the chest and results of other examinations were essentially negative . Examination of sputum revealed malignant cells . (Fig . 2 .) On bronchoscopic examination no tumor was seen . Bronchial washings from the right side showed carcinoma cells and those from the left side showed none . A stereoscopic roentgenogram revealed a rounded mass in the right lower part of the lung field which in a tomogram appeared to be 2 cm . in diameter . At exploration of the right side of the chest a small tumor

USES

Examination of sputum and bronchial secretions is most useful in several situations : z . It is useful in the diagnosis of bronchogenic carcinoma of an upper lobe of the lung because lesions in this location are very difficult and often impossible to visualize bronchoscopically . Frequently a positive cytologic diagnosis gives the only definite evidence of carcinoma in this location before operation . 2 . It is useful, too, in the diagnosis of bronchogenic carcinoma which is peripherally situated in the lung . These lesions, however, do not give a high incidence of positive cytologic findings . It is necessary, of course, to have a bronchus communicating with the carcinoma in order to have cytologically positive sputum ; 4 63

Pulmonary Cytology was found in the middle lobe of the lung with extensive involvement of the hilar lymph nodes . A lymph node was removed from the superior mediastinum which proved to be an undifferentiated large cell type of carcinoma . The condition was regarded as inoperable and the thorax was closed . The patient died eight days later . We have found that results of cytologic examination are most likely to be positive in cases of small cell or "oat" cell carcinoma of the lung and next most likely to be positive in cases of squamous cell carcinoma of the lung . This is true because these carcinomas involve the larger bronchi and produce ulcer-

ation of the mucosa in most instances . We have riot found results of cytologic examination to be positive in cases of adenoma of the lung in which bronchial niucosa over the adenoma is intact. This observation has been of help in distinguishing between adenoma of the bronchus and small cell undifferentiated carcinoma . SUMMARY

The cytologic examination of sputum and bronchial secretions and washings is a valuable procedure in the diagnosis of bronchogenic carcinoma . It also may give evidence of metastatic carcinoma of the lungs and alveolar cell carcinoma .

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