‘Wallpaper paste sign’ of mucinous breast carcinoma

Introduction: Mucinous carcinoma of the breast is an uncommon disease, characterized by a large amount of mucin production. Histologically, it is classified into two subgroups— pure type and mixed type. It usually affects postmenopausal women and is commonly associated with good prognosis. case report: We present a case of a 53-year-old female with a palpable breast lump which was clinically as well as radiologically suspicious of breast cancer. A free hand needle core biopsy was carried out. the biopsy material retrieved had a distinctive gross appearance, with soft, gelatinous consistency and a glistening clear surface. On this typical macroscopic appearance, a diagnosis of ‘mucinous breast carcinoma’ was made, which was subsequently confirmed on histological examination. the typical gross appearance of specimen on needle core biopsy is similar to the appearance of wallpaper paste; hence we describe it as ‘wallpaper paste sign’. conclusion: the hallmark of mucinous carcinoma is extracellular mucin production that gives it a typical glistening macroscopic appearance. Keeping in mind the ‘wallpaper paste sign’ we describe, mucinous breast carcinoma can be