Corpora amylacea in sputum smears: Incidence and clinical significance.

OBJECTIVE

To examine conventional sputum smears for the presence of corpora amylacea (CA), determining their incidence and clinical significance.

METHODS

A retrospective 4-year cohort study was undertaken of sputum samples from 1176 consecutive patients for the presence of CA. Variables such as age, sex, smoking status, and the presence or absence of haemoptysis were extracted from the medical record. A random group of 50 patients was selected as a control group, and a random group of 50 patients whose ages were below 49 years was also included as an age-based control.

RESULTS

A total of 1075 of the initial cohort of consecutive patients were included in the study. from these, there were 6898 sputum smears, of which 1.91% (132 smears) contained CA, corresponding to 9.86% of the cohort of patients (106 patients). There was a strong, positive, statistically significant correlation between age and CA presence (τb  = .402, P < .001), which supports that CA are associated with older patients. The results of a binary logistic regression indicated that there was a significant association between age, diagnosis of chronic obstructive pulmonary disease and CA presence (χ2  = 49.051, df = 2, P < .001).

CONCLUSIONS

The presence of CA in sputum smears is related to age, being much more frequent in older people. Moreover, CA are related to non-neoplastic lung diseases.