Background: The clinical features of invasive lobular carcinoma (ILC) of the breast have remained unclear due to the rarity of such cases. This study investigated the clinical and pathological features of ILC.
Methods: The medical records of 413 patients with invasive breast cancer who underwent surgery in our department were reviewed. These cases included 13 patients with ILC (3.1%).
Results: The age of the patients ranged from 36 to 77 years old (mean, 56). The tumour size was evaluated as T1 in five patients, T2-4 in 8. The lymph node metastasis was diagnosed as negative in six patients, positive in six. In this patient population, 11 (85%) and nine (69%) patients were positive for oestrogen and progesterone receptors, respectively. The 5-year survival rate was 76.2%, which was not significantly different from other types of invasive breast cancer. Extensive intraperitoneal metastasis was observed in two of the three patients. Two patients had bilateral carcinoma and one patient had a multicentric lesion in the ipsilateral breast.
Conclusion: Multicentric development of breast cancer and intraperitoneal metastasis were one of clinical characteristics of ILC. The prognosis of ILC was not significantly different from other types of invasive breast carcinoma.