[Stump curettage cytologic examination of excised tumor is more sensitive than histologic examination]

Some malignant lung tumors relapse on the cutting line in spite of a negative histologic stump. Histologic examination is limited to only few sites of excised sample. Conversely, stump curettage cytologic examination is useful to examine the whole area. We conducted a simultaneous histological and cytological study to assess the value of stump curettage cytologic examination. Forty-two staple-excised peripheral small lesions (< 3 cm in diameter) from 35 patients, aged 50 to 82 years, were assessed. Ten were subject to VATS and 32 to thoracotomy. Preoperative diagnoses were: 15 undiagnosed lesions (lung cancer: 8, benign lesion: 7), 18 lung cancers and 9 metastatic cancer. The whole area of the excised stump was curetted before observing the cross section to prevent malignant cell contamination. After that, the sample was cut vertically to staple line and pathologically examined. Thirty-eight percent (11/29) of histologically negative stumps were cytologically positive. Twenty-seven malignant lesions underwent only excision and 6 stumps were finally cytologically positive. Two of 6 cytological positive lesions relapsed at the staple site were excised at the second operation. Stump curettage cytological examination was more sensitive than histological examination to detect malignant cell contamination.