EAR SMEARS 



108 



EAR SMEARS 



nasal Sinuses; St. Louis: C. V. Mosby 

 Co. 1936, 383 pp.) believes that increase 

 of eosinophiles in affections of the 

 middle ear is due to the chronicity of 

 the infection rather than to an allergic 

 condition comparable to that which 

 appears in the nose. Eosinophiles are 

 frequently noted where there is a con- 

 tinual irritation factor. In aural polyps 

 there may be eosinophilic infiltration 

 in the tissue and if discharge is present 

 eosinophiles may be seen. Proetz, A. W. 

 (Ann. Otol., Rhin. and Laryngol., 1931, 

 40, 67) reported in detail an asthmatic 

 infant who had attacks of otitis media 

 accompanied by asthma. The secre- 

 tion from the ear did not contain eo- 

 sinophiles. The problem merits careful 

 consideration and further investigation. 



Considerable significance in the past 

 has been attached to the microscopic 

 findings of cholesterol crystals and fatty 

 degenerated epithelium in chronic mid- 

 dle ear suppurations. Some have re- 

 garded these cytological findings as 

 diagnostic of cholesteatoma of the mid- 

 dle ear and mastoid. Particular care 

 must be taken in these conditions when 

 studying the cytology of the ear, as it 

 has been shown by Dean, L. W., Jr. and 

 Pfingsten, M. G. (Ann. Otol., Rhinol. 

 and Laryngol., 1933, 42, 484-496) that 

 characteristic cholesterol crystals and 

 positive chemical tests for cholesterol 

 can be found in acute otitis media and 

 in external otitis as well as in chronic 

 otitis media. Normal cerumen from 

 the ear may contain more amorphous 

 and crystalline cholesterol than choles- 

 teatoma. It is thus important that 

 the ear canal be thoroughly cleansed 

 and that the exudate studied, be taken 

 from the point of perforation of the 

 drum membrane. It would seem that 

 the finding of cholesterol crystals along 

 with fatty degenerated epithelium in 

 aural secretions is not alone diagnostic 

 of cholesteatoma, but may be sugges- 

 tive in the light of the clinical symp- 

 toms. 



Cholesterol crystals show double re- 

 fraction of polarized light, so are best 

 observed in unstained direct smears of 

 secretions with a microscope equipped 

 with polarizer and analyzer. Since 

 lipoid substances are the only ones, so 

 far as is known, that doubly refract 

 polarized light, this method is simple 

 and convenient for detecting cholesterol 

 in its crystalline state. When the Nicol 

 prisms of the polarizing apparatus are 

 crossed the field appears dark, but 

 cholesterol crystals, when present, are 

 brightly illuminated against the dark 

 background. They are seen in the char- 

 acteristic flat rhomboid plates, often 



with irregular edges. The crystals, be- 

 ing very fragile, may be broken into 

 fragments lacking true crystal forma- 

 tion. What the actual association of 

 the crystal formation may be to the 

 fatty degenerated epithelial cells is not 

 known. 



Cholesterol is also evident in the 

 secretions of infected ears and in ceru- 

 men in the form of liquid crystals ob- 

 served only with a polarizing micro- 

 scope. They appear as small luminous 

 spheres with a black maltese cross 

 superimposed on each one. The phe- 

 nomenon is caused by a molecular for- 

 mation of cholesterol esters that takes 

 place in a liquid medium. The maltese 

 crosses are the result of interference 

 lines of light rays passing through the 

 crystals. They are sometimes seen 

 within large phagocytic cells. Nothing 

 is known of their significance except 

 that their presence indicates choles- 

 terol. 



In mastoiditis the smear is equally 

 useful in helping to evaluate whether 

 the condition is acute or chronic. Some 

 consider the clinical signs and symp- 

 toms of the patient sufficient, but in 

 these serious diseases every laboratory 

 aid available is needed to facilitate 

 diagnosis. In acute suppurative mas- 

 toiditis, the secretion, if there is ample 

 opportunity for it to drain through the 

 tympanic membrane, may contain large 

 lipoid bone phagocytes, which hint at 

 bone destruction. These same cells are 

 usually found at mastoidectomy in cell 

 pockets of diseased bone containing 

 purulent material where the bone is 

 actively being destroyed. They were 

 first observed in the ear and mastoid 

 by Pfingsten, M. G. in 1934 by using 

 the supravital staining technique as 

 developed by Sabin, F. R. (Bull. Johns 

 Hopkins Hosp., 1923, 34, 277-288). 

 Their identification was reported at 

 that time to the clinical conference for 

 Otolaryngology, Barnes Hospital. A 

 complete report concerning these cells, 

 with case histories, before and after 

 the use of antibiotics, is to be published 

 this year by Bryan, M. P. and Bryan, 

 W. T. K. 



Such cells are best studied in the liv- 

 ing condition since stains and fixations 

 dissolve the lipoid substance within 

 the cell leaving large empty vacuoles 

 in the cytoplasm giving it a foamy 

 appearance. The cell membrane in ei- 

 ther the fixed or living condition may 

 be indistinct and irregular. The nu- 

 cleus is usually eccentric and sometimes 

 double. The cells are for the most 

 part spherical varying in size from 20- 

 42 microns in diameter. In comparison 



