がんの科学と治療

Radiologically Unifocal Invasive Breast Carcinomas: Large-Section Histopathology Correlate and Impact on Surgical Management

Abstract

Tibor Tot and Maria Gere

Background: Most breast carcinomas are morphologically complex, comprising both in situ and invasive components that can be unifocal, multifocal, or diffuse. Pre-operative radiological mapping often reveals this complexity, but even in the era of modern multimodality breast imaging lesions may remain undetected. Methods: We studied the sub gross morphology of tumors in a series of invasive carcinomas determined to be unifocal on pre-operative multimodal radiological imaging. We focused on histological outcome, margin status, and type of surgery. All of the surgical specimens were documented in large-format histological slides.
Results: A total of 44.5% (344/773) of the tumors had separate invasive and/or in situ foci in large-format histopathology slides, in addition to the radiologically detected tumor focus. The foci occupied an area ≥ 40 mm in 29.0% (224/773) of the cases, indicating extensive disease. Close/dirty margin upon histological examination was associated with extensive disease (32.1% vs 5.6%, RR 5.6924, p < 0.0001), multifocality of the invasive component (26.0% vs 3.3%, RR=7.9755, p=0.0001), and breast conservation (15.4% vs 6.3%, RR=2.4476, p=0.0036), but the differences were found only for extensive tumors. Mastectomy was chosen as the primary or complete intervention in 28.3% (219/773) of cases, mostly in multifocal and extensive tumors.
Conclusion: Our results indicate the presence of extensive disease in a considerable number of breast cancer cases judged pre-operatively as unifocal. Removing the radiologically detectable tumor focus with “no ink on the tumor” may not be sufficient in such cases.