Robotic-assisted Resection of Diaphragmatic Osteochondroma

Neoplasms arising from the diaphragm are not typically seen in clinical practice, though they may inflict significant morbidity and mortality. In the realm of thoracic surgery, osteochondromas are only encountered at the thoracic wall or vertebra. In this study, we describe a case of an osteochondroma arising from the diaphragm masquerading as a malignant lesion. The tumor was resected via robotic-assisted means and the patient was discharged with no complications. Neoplasms arising from the diaphragm are not typically seen in clinical practice, though they may inflict significant morbidity and mortality. In the realm of thoracic surgery, osteochondromas are only encountered at the thoracic wall or vertebra. In this study, we describe a case of an osteochondroma arising from the diaphragm masquerading as a malignant lesion. The tumor was resected via robotic-assisted means and the patient was discharged with no complications. Osteochondromas are extremely rare tumors of the thorax, with only 3% of solitary osteochondromas having either costal or vertebral origin.1Kadu V.V. Saindane K.A. Goghate N. Goghate N. Osteochondroma of the rib: a rare radiological apeareance.J Orthop Case Rep. 2015; 5: 62-64PubMed Google Scholar Diaphragmatic tumours are rarer entities, with only 200 cases of primary and secondary neoplasms described in literature.2Baldes N. Schirren J. Primary and secondary tumors of the diaphragm.Thorac Cardiovasc Surg. 2016; 64: 641-646Crossref PubMed Scopus (7) Google Scholar With the preponderance of benign and malignant lesions of the diaphragm being equal, the malignancy potential of diaphragmatic tumors cannot be underestimated. We therefore describe a case report of a patient presenting with features mimicking a malignant diaphragmatic lesion, only to be unmasked as an osteochondroma. A 56-year-old Chinese gentleman with background medical history of hypertension and hyperlipidemia presented with loss of weight of 6 kg over 6 months and loss of appetite. An esophagogastroduodenoscopy and colonoscopy were performed as workup for the loss of weight and yielded nothing remarkable. He was found to have microscopic hematuria and was evaluated by the urologist with an intravenous urogram to rule out a malignant neoplasm. It revealed a right hypochondriac globular calcified opacity that, upon evaluation with a computed tomography of thorax, abdomen, and pelvis, showed a calcified pleural-based lesion in the right lower lobe (Figure 1). The case was subsequently discussed in a multidisciplinary tumor board and an unanimous decision was made for further endocrinology workup of loss of weight. The workup did not yield significant results and the decision was made for resection of the tumor. No preoperative biopsy was attempted because of the anatomically tricky location of the tumor. The patient was prepared for surgery in the left lateral position with the right lung deflated using a double-lumen endotracheal tube. The minimally invasive surgery was performed using the da Vinci Xi (Intuitive, Sunnyvale, CA) surgical system using the 3-arm robotic port technique. The robot pedestal was oriented towards the head end and the working arms were oriented towards the diaphragm. Intraoperatively, there was a hard spherical mass arising from the right dome of diaphragm with white deposits adhering to the chest wall and edge of the right lower lobe (Figure 2). The mass was carefully dissected from the diaphragm with a harmonic scalpel without penetrating the diaphragm. A lower-lobe wedge dissection was performed over the areas with white deposits. A 24-F chest drain was inserted before closure. The patient was transferred to the high dependency unit for monitoring postoperatively. He was shifted to the general ward on postoperative day 1 with the chest drain removed and discharged on the same day with no complications. Histology revealed an osteochondromatous lesion characterized by trabeculae of lamellar bone associated with chondroid tissue (Figure 3). No evidence of malignancy was noted. In this study, we examined a case of a robotic-assisted resection of an osteochondromatous lesion adherent to the diaphragm. Significantly, the malignant façade that the tumor put up was only unmasked via histological means, with clinical and radiologic investigations pointing strongly towards an invasive lesion. The loss of weight, loss of appetite, as well as negative medical workup for systemic diseases pointed towards the neoplasm as the likely cause. The robotic-assisted platform was utilized in this instance and ensured a minimally invasive and complication-free procedure on the diaphragm.3Roh Y. Masrur M. Giulianotti P.C. Robotic-assisted resection of a retrocaval peridiaphragmatic mass.JSLS. 2014; 18: 146-149Crossref PubMed Scopus (2) Google Scholar,4Lee K. Lok H. Fung A. et al.Successful robotic extirpation of diaphragmatic seeding of hepatocellular carcinoma after previous rupture.J Robotic Surg. 2019; 13: 525-528Crossref PubMed Scopus (3) Google Scholar