Submit Manuscript | http://medcraveonline.com Introduction Ewing’s sarcoma/Primitive neuroectodermal tumors (EWS/PNET) comprise a group of rare malignant and aggressive tumors, known to originate from migration of embryonic cells of the neural crest. They characterstically display small round cell morphology and variable neuroectodermal differentiation. These tumors have a predilection for long bones, pelvis, and ribs, occuring commonly in the children and adolescents. 1 Although extraskeletal involvement of soft tissues either primary or metastatic is quite rare; few cases involving the lung, pleura and lymph node have been reported. 2 Extra-mammary metastasis to the breast is quite uncommon with prevalence ranging from 1.7 to 6.6% and is an indicator of disseminated disease with a poor prognosis. 3,4 Lymphoma, malignant melanoma, rhabdomyosarcoma and lung carcinoma are common tumors that metastasize to the breast. Sarcomas and more specifcally Ewing’s sarcoma are extremely rare source of origin of breast metastasis with only few cases reported in the literature till date. 4,5 Ancillary techniques are necessary for accurate diagnosis and typing of malignant tumors of breast, due to variation in their prognosis and ways of management. Owing to their usual superfcial and accessible locations, fne needle aspiration cytology is usually an important screening tool to evaluate the lesion as benign or malignant and if malignant whether primary or metastasis. However, cytology and histopathological biopsy along with immunohistochemical examination forms the mainstay of diagnosis. Moreover, highlighting the characteristic transcript t (11, 22) at molecular level is necessary for a confrmatory diagnosis. 6 This rare case report shows the importance of a keen cytological and histopathological examination in early diagnosis of metastatic palpable breast lump from a primary Ewing’s sarcoma of femur to assure prompt treatment and avoid any unnecessary radical operation. Case summary A 22 year old female presented to the surgical OPD with a gradually increasing painful lump in the right breast since the past 3 months. She also complained of low grade fever with loss of weight and appetite for 5-6months duration. There was no history of cough, chest pain, any loco-regional trauma or any signifcant family history. She also complained of gradually increasing pain in left knee since 6 months with decreased mobility. On examination, the patient was average built with adequate nutrition. Systemic examination was apparently normal with presence of mild pallor. Breast examination revealed a frm, irregular, non-tender and mobile lump of size 3cmx2cm in upper outer quadrant of right breast without any skin, lymph node or deep structural involvement. A doppler ultrasound was suggestive of malignancy with BIRADS grade IVa. Local examination of left knee joint showed an ill-defned frm swelling and tenderness with decreased mobility but absence of any redness or ulceration. X-ray of left knee joint showed an ill-defned lytic lesion with mild periosteal reaction in distal femur along with pathological fracture. Magnetic resonance imaging on both T1 and T2 weighted signals showed an ill-defned mass of increased heterogenesity infltrating into adjacent tissue. On the basis of which a differential of Ewing’s sarcoma and chronic osteomyelitis was given. A fne needle aspiration cytology from both the sites of lesion was performed which showed strikingly similar cytological features of individually scattered as well as cohesive clusters of dual population of cells, comprising of small round hyper chromatic cells with scant cytoplasm and large atypical round to polygonal cells with increased nuclear-cytoplasmic ratio, coarse granular chromatin, indistinct nucleoli and scant cytoplasm. Occasional foci of rosette formation and nuclear moulding were also seen Figure 1. Based on clinic-pathological fndings a diagnosis of small blue round cell tumor probably Ewing’s sarcoma of left distal femur with metastasis in right breast was made. For confrmation, an incisional biopsy from both the sites was performed which showed tumor areas comprising of sheets of cells, with predominantly small round cells with hyper chromatic nuclei, scant clear cytoplasm and indistinct cell Adv Cytol Pathol. 2017;2(2):63‒66 63 © 2017 Akhtar et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and build upon your work non-commercially. Ewing’s sarcoma of femur with metastasis to the breast: a rare case report Volume 2 Issue 2 - 2017 Kafl Akhtar, Alia Ehsan, Asim I Khan, Mubarak Shraim Department of Pathology, Aligarh Muslim University, India Correspondence: Kafl Akhtar, Department of Pathology, Jawaharlal Nehru Medical College, Aligarh Muslim University, Aligarh (UP), India, Email drkaflakhtar@gmail.com Received: October 14, 2016 | Published: March 22, 2017 Abstract Ewing’s sarcoma/Peripheral primitive neuroectodermal tumors ((EWS)/PNET) are highly malignant small round cell tumors, occurring primarily in limb bones of children and young adults. Usual sites of metastasis are lung, pleura, other bones and occasionally to lymph node, central nervous system and liver. Metastasis to the breast is an extremely rare entity with only few cases reported till date. Nevertheless, it should always be considered as a differential if there is a history of Ewing’s sarcoma in a patient presenting with a palpable breast lump. Breast metastasis is indicative of advanced disease with poor prognosis requiring prompt diagnosis and treatment. We hereby present a case of a 22 year old female presenting with a palpable breast lump of 3 months duration, who had a past history of partially treated knee swelling 6 months back. Fine needle aspiration cytology from the breast lump as well as the lower end of femur revealed a similar morphology comprising of dimorphic population of small round cells and larger cells, singly and in rosettes with reticulo-granular chromatin and scant cytoplasm. Based on the immuno-histopathological examination of the excised tissue, the diagnosis of Ewing’s sarcoma femur metastasizing to the breast was made. Keywords: breast, cytology, ewing′s sarcoma, histopathology, metastasis Advances in Cytology & Pathology Case Report Open Access