SURGERY Primary Leiomyosarcoma of Humerus Presenting with Pathological Fracture and Treated Initially with Inadvertent Plate Fixation: a Case Report with Literature Review Kunal Nandy 1 & Abhijeet Ashok Salunke 1 & Jaymin Shah 1 & Mayur Kamani 1 & Chirag Agrawal 1 & Sudam Sadangi 1 & Ronak Vyas 1 & Shashank Pandya 2 Accepted: 20 August 2020 # Springer Nature Switzerland AG 2020 Abstract Leiomyosarcoma is a malignant tumor of smooth muscle origin and commonly diagnosed in the uterus, gastrointestinal tract, and mucous membranes or as metastasis to the skeletal system. Primary leiomyosarcoma of bone is an uncommon type of tumor. Patient with primary bone sarcoma may present with a pathological fracture following a trivial injury, resulting in pain, swelling, and deformity. The pathological fracture needs to be evaluated with a high index of suspicion and proper investigations must be performed prior to fracture fixation. We present a case of primary leiomyosarcoma of humerus, who presented as pathological fracture and underwent inadvertent plating at a peripheral hospital. We treated this patient with wide resection of the tumor and the reconstruction was performed with an implant (Kuntscher’s nail and extra-articular plate) with bone cement spacer. The use of this novel method allowed us to perform implant fixation with small distal humerus bone segment and preserve native elbow joint. In this case report, we aim to highlight the importance of thorough preoperative evaluation and keeping a high index of suspicion while dealing with suspected pathological fractures to differentiate between primary and metastatic disease. Keywords Leiomyosarcoma . Inadvertent implant fixation . Leiomyosarcoma of bone . Rodded sarcoma Introduction Leiomyosarcoma is a sarcoma that commonly affects the uterus and gastrointestinal tract and is observed in intra- peritoneal and retroperitoneal locations [1–3]. Salunke et al. had described a case of intra-osseous leiomyoma of the calcaneum which was treated with curettage [4]. Malignant tumor of smooth muscle origin arising primar- ily from bone is uncommon [1–3]. The rarity of skeletal leiomyosarcoma and the scarcity of clinical and radiolog- ical findings make it difficult for clinicians to diagnose this tumor. These tumors are observed in the epiphyseal and metaphyseal location of the long bone [ 2 , 3 ]. Radiologic evaluation of leiomyosarcoma of bone shows ill-defined osteolytic lesion and may lead to pathological fracture of the affected bone. Patient with suspected pathological fracture caused due to trivial trauma or with past medical history needs to be evaluated with a high index of suspicion. Adams et al. reported the consequences and prevention of inadvertent internal fixation of primary osseous sarcomas [5]. A re- view of the literature shows that unplanned surgical treat- ment in primary bone sarcoma or soft tissue sarcoma leads to poor oncologic outcomes [5–9]. We present a case of primary leiomyosarcoma of hu- merus, who presented as pathological fracture and underwent inadvertent plating at a peripheral hospital. We treated this patient with wide resection of the tumor and the reconstruction was performed with an implant cement spacer. We emphasize the need for bone biopsy in the management of primary bone sarcoma. This article is part of the Topical Collection on Surgery * Abhijeet Ashok Salunke drabhijeetsalunke@gmail.com 1 Department of Surgical Oncology, The Gujarat Cancer Research Institute (GCRI), Ahmedabad, Gujarat, India 2 The Gujarat Cancer Research Institute (GCRI), Ahmedabad, Gujarat, India SN Comprehensive Clinical Medicine https://doi.org/10.1007/s42399-020-00479-7