[Small cell bronchial carcinoma following chemotherapy. Morphological findings]

Resection specimens of 14 patients with small cell bronchial carcinoma after neoadjuvant chemotherapy were processed histologically and graded according to a three-step regression grading system: grade I, no or only slight tumor regression; grade II, incomplete tumor regression; grade III, complete tumor regression without vital tumor tissue. In five patients with either no vital tumor tissue or only small tumor remnants in the resection samples, a typical sequence of central fresh tumor necrosis, foam cell rim, vascular granulation tissue and peripheral scar formation was seen. This morphological finding may be interpreted as a characteristic, but unspecific parameter of good response to preoperative chemotherapy. The presence of vital tumor rims surrounding the capillary bed with intermingled necrotic foci, however, argues in favor of spontaneous tumor regression, which is commonly observed in small cell lung cancer.