Abstract
Background: Inflammatory breast cancer (IBC) is a rare and aggressive breast cancer. Histiocytoid lobular carcinoma (HLC) is a rare type of invasive lobular carcinoma with morphologic characteristics resembling those of histiocytes. Herein, we report a case of an HLC patient presenting with the clinical features of IBC. Case: A 70-year-old woman presented with skin erythema of the left breast for a month. Ultrasonography of the left breast showed skin thickening, an anechoic area, and axillary lymphadenopathy. No elevated inflammatory markers were observed during laboratory examination. Fine needle aspiration cytology (FNAC) of the left breast was performed. In the cytology specimens, dyscohesive neoplastic cells showed histiocytoid features characterized by eccentrically located nuclei and abundant foamy or granular cytoplasm, consistent with HLC. Core needle biopsy specimens showed neoplastic cells with the same morphology as those in FNAC specimens. The cells were negative for E-cadherin and positive for GCDFP15, confirming the diagnosis of HLC. On the basis of clinical features and histocytological findings, the diagnosis of IBC was made. Two years later, left total mastectomy was performed. Histopathological findings showed neoplastic cells of HLC infiltrating the skin and pectoralis major muscle, and permeating dermal lymphatic vessels. Conclusion: An evaluation based on a combination of various results including clinical information and radiologic findings is necessary for the diagnosis of IBC. In the present case, cytology was important for the diagnosis of IBC and useful for estimating the histological type.
