Carcinoma breast masquerading as extramedullary plasmacytoma breast: An unusual case report with review of literature Nidhi Mahajan, Annapurna Saksena, Parth Desai, Seema Kaushal, Shyama Jain n , Ronak Patel Department of Pathology and Department of Radiology, Maulana Azad Medical College, New Delhi 110002, India article info Article history: Received 5 March 2015 Received in revised form 26 February 2016 Accepted 4 April 2016 Keywords: Myeloma Plasmacytoma Carcinoma breast Morphological mimics Cytology abstract Fine needle aspiration cytology continues to be the first line modality for definitive diagnosis of palpable and non palpable breast masses. Despite its high accuracy, some cases may pose a diagnostic dilemma. We present a case of a 42 year old female who was clinico-radiologically and cytologically mislabelled as plasmacytoma but was subsequently diagnosed as poorly differentiated carcinoma breast on histo- pathology and immunohistochemistry. Aspiration cytology is a minimally invasive procedure with rapid turn around time but in cases with unusual cytological picture, a core biopsy along with im- munohistochemistry must accompany cytology to maximize the preoperative diagnosis of malignant breast lesions in order to ensure appropriate management. & 2016 Published by Elsevier Ltd. 1. Introduction Fine needle aspiration cytology (FNAC) is a safe, cost effective and accurate investigative tool for evaluation of breast lesions. It has a wide range of accuracy (72–99%) in diagnosis of breast ma- lignancies and in their subtyping [1]. Surgeons insist upon diag- nosis on aspiration cytology and consider it definitive for many subtypes to plan the mode of treatment. However, some cases may pose hindrance on cytology leading to misdiagnosis. We present a case of a 42 year old female with right breast lump mislabelled on cytology as plasmacytoma and subsequently diagnosed as poorly differentiated carcinoma on histopathology. This case depicts a clinical, radiological and cytomorphological mimicry of breast carcinoma as plasmacytoma and emphasises the awareness of variable features of the former on cytology as its treatment differs radically. 2. Case report A 42 year old postmenopausal female presented with the complaint of a lump in the right breast for the past 2 months. The lump was painless, gradually increasing in size and not associated with nipple discharge. She had no history of bone pain, weight loss, fever and no family history of breast cancer. Clinical examination revealed a 2 Â 2 cm firm, non-tender lump in the upper inner quadrant of right breast (Fig. 1(a)). No skin changes or nipple discharge was observed. Right sided axillary lymphadeno- pathy was also seen. Mammogram showed a well circumscribed round lesion with soft tissue density in the upper inner quadrant with a sharp interface with adjacent fibro-glandular parenchyma. There was absence of internal calcification or any architectural distortion (Fig. 1(b) and (c)). Ultrasonography revealed a well de- fined 2.5 Â 2.4 cm hypoechoic mass with moderate internal vas- cularity and posterior enhancement. There were few hyperechoic rims in the centre. Radiological findings were suggestive of a be- nign lesion. FNAC was performed as per standard procedure and air dried Giemsa stained smears were examined. Smears showed highly cellularity with sheets of plasma cells in different stages of maturation. Cells had abundant basophilic cytoplasm, a peri- nuclear hof, an eccentrically placed nucleus and prominent nu- cleolus (Fig. 2(a)). Many bi and multinucleated forms were also seen and mitosis was frequent (Fig. 2(b)). Immunocytochemistry (ICC) for kappa and lambda was non contributory. In view of these dispersed mature and immature plasma cells, a thorough hae- matological, biochemical and radiological workup of the patient was advised to exclude a plasma cell dyscrasia. Serum protein, creatinine, blood urea, calcium and serum protein electrophoresis were within normal limits. Urine for M protein was negative. Hemogram revealed haemoglobin of 11.5 g/dl with normal leuco- cyte and platelet count. Bone marrow aspirate showed normal hemopoiesis with no increase in plasma cells. Based on the above clinical, radiological and cytological features, a diagnosis of Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/ctrc Cancer Treatment Communications http://dx.doi.org/10.1016/j.ctrc.2016.04.001 2213-0896/& 2016 Published by Elsevier Ltd. n Corresponding author. E-mail address: jainshyama@gmail.com (S. Jain). Cancer Treatment Communications 8 (2016) 5–7