AOSHIMA Hiroe

ISAKA Tamami

KANZAKI Masato

MATSUMOTO Takako

MITSUBOSHI Shota

NAGASHIMA Yoji

SAWADA Tatsuo

SHIDEI Hiroaki

Tokyo Women’s Medical University

Robot-Assisted Thoracoscopic Tumor Resectionof Lymph Node Metastasis of an Unknown PrimarySite: A Case Report著者名 ISAKA Tamami, MITSUBOSHI Shota, SHIDEIHiroaki, AOSHIMA Hiroe, MATSUMOTO Takako,SAWADA Tatsuo, NAGASHIMA Yoji, KANZAKI Masatojournal orpublication titleTokyo Women's Medical University Journalvolume 4page range 98-103year 2020-12-25URL http://hdl.handle.net/10470/00032754―98―Case ReportTWMUJ 4: 98-103, 2020Robot-Assisted Thoracoscopic Tumor Resection of Lymph Node Metastasis ofan Unknown Primary Site: A Case ReportTamami Isaka,１Shota Mitsuboshi,１Hiroaki Shidei,１Hiroe Aoshima,１Takako Matsumoto,１Tatsuo Sawada,２Yoji Nagashima,３ and Masato Kanzaki１１Department of Thoracic Surgery, Tokyo Women’s Medical University, Tokyo, Japan２Division of Pathological Neuroscience, Department of Pathology, Tokyo Women’s Medical University School of Medicine, Tokyo, Japan３Department of Surgical Pathology, Tokyo Women’s Medical University, Tokyo, Japan(Accepted August 12, 2020)(Advance Publication by J-STAGE September 25, 2020)Cancer of an unknown primary site (CUP) accounts for approximately 3% of all cancer cases. Among these cases, mediasti-nal lymph node cancer is comparatively rare, and there are no established treatment methods or approaches. Excision of CUPis feasible with the best methods. We herein report a case of mediastinal lymph node CUP resection by robot-assisted thora-coscopic surgery (RATS). The patient was a 60-year-old man. A chest computed tomography (CT) scan identified swellingin the mediastinal lymph node (right tracheobronchial lymph node; #4R) with another organ suspected as the site of the pri-mary lesion, but it was not detected through positron emission tomography (PET). The patient was diagnosed with CUP withlymph node metastasis and mediastinal lymph node dissection was performed via RATS. Histopathological examination re-vealed desmoplasia in the lymph nodes. Immunohistochemically, the tumor was positive for CK7, TTF1, and napsin A, butnegative for CK20, CK5/6, CDX2, p40, and AFP, indicating lung-derived adenocarcinoma. In the narrow space such as themediastinum, RATS is a useful procedure for resectable mediastinal tumors.Key Words: robot-assisted thoracoscopic surgery (RATS), cancer of unknown primary site (CUP)IntroductionCancer of an unknown primary site (CUP) accounts forapproximately 3% of all the clinical cancer cases, and itis frequently linked with mortality.１，２Among these cases,mediastinal lymph nodal involvement is comparativelyrare, and there are no established therapeutic strategies.３To determine the primary site and select an appropriatetherapeutic regimen, biopsy and/or excision of the CUPis required. Furthermore, the resected tissue sample canbe used for comprehensive cancer genome analysiswhich will also assist with selecting an appropriate thera-peutic option for CUP.３，４We herein report a case of CUP metastasizing to themediastinal lymph node. The lesion was successfully re-sected by robot-assisted thoracoscopic surgery (RATS).Histopathologically, the lung was indicated as the pri-mary site.Corresponding Author: Masato Kanzaki, Department of Thoracic Surgery, Tokyo Women’s Medical University, 8-1 Kawada-cho,Shinjuku-ku, Tokyo 162-8666, Japan. kanzaki.masato@twmu.ac.jpdoi: 10.24488/twmuj.2020006CopyrightⒸ 2020 Society of Tokyo Women’s Medical University. This is an open access article distributed under the terms of CreativeCommons Attribution License (CC BY), which permits unrestricted use, distribution, and reproduction in any medium, provided theoriginal source is properly credited.―99―Figure　1　Preoperative imaging findings.(A) Chest computed tomography scan showing a solitary mediastinal mass with 37 mm in maximum diameter without invasion surrounding tissues.(B) 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) of the patient showing an ab-normal uptake of FDG with a maximum standardized uptake value of 5.92 in the tumor.(C) Coronal section of the FDG-PET showing no abnormal FDG accumulation other than the tumor. Case PresentationA 60-year-old man presented with a mediastinal tumorby chest computed tomography ( CT ) during medicalcheckup and was referred to our hospital. His physicalfindings were normal. He had been smoking 30 cigarettesper day for 37 years, had a comorbidity of hypertension,but had no past history of malignant tumors.Although blood tests found elevated Sialyl Lewis X(SLX) levels of 61 U/mL, both carcinoembryonic antigen(CEA) and cytokeratin subunit 19 fragment (CYFRA)levels were normal. No other abnormalities were identi-fied in the blood sample.Chest CT revealed an isolated mediastinal mass meas-uring 37 mm in the maximum diameter without invasionto the adjacent tissues. No abnormal shadows were iden-tified in the lung fields ( Figure 1 A ) . 18 F-fluorodeoxyglucose (FDG) accumulation was identifiedin the tumor using FDG positron emission tomography(PET), and the maximum standardized uptake value was5.92. No abnormal FDG accumulation was found inother organs (Figure 1B and C).Endobronchial ultrasound transbronchial needle aspi-ration (EBUS-TBNA) was performed and he was diag-nosed with adenocarcinoma. Since no primary site organcould be identified, the diagnosis was mediastinal lymphnode CUP, and robot-assisted thoracoscopic surgery(RATS) was performed.The patient was intubated with a double-lumen en-dotracheal tube for one-lung ventilation under generalanesthesia, and placed in a left lateral decubitus position.RATS excision of the mediastinal tumor was performedwith four port incisions and a 4-cm utility thoracotomy asan assistant port. The da Vinci Surgical System (ModelXi; Intuitive Surgical, Inc, Sunnyvale, CA, USA) wasused. RATS began with a total of four 8-mm ports in-serted in the 7th intercostal space (ICS) at the anteriorside as the 1st arm, in the 8th ICS mid-axillary line as the2nd arm, in the 8th posterior axillary line as the 3rd arm,and in the 8th posterior side as the 4th arm, plus an assis-tant port in the 4th ICS (Figure 2). A robotic arm wasmounted to the port in the 8th ICS, with Cadiere grasping―100―Figure　2　Schematic illustration of four port incisions and a 4-cm utility thoracotomy as an assistant port.A total of four 8-mm ports (circle) were inserted in anterior to 7th intercostal space (ICS), 8th ICS mid-axillary line, posterior axil-lary line, and posterior. An assistant port (line) was made at 4th ICS.ICS, intercostal space; A, assistant port; C, camera. forceps on the 1st arm, bipolar fenestrated grasping for-ceps on the 2nd arm, and monopolar spatula on the 4tharm. The camera scope was inserted into the 8th ICSmid-axillary line port and was used for 30° oblique view-ing. No adhesions were found within the right thoraciccavity, and there were no abnormalities in the lungs. Thetumor was located in the right lower paratracheal lymphnodes (4R) on the cranial side of the azygos vein (Fig-ure 3A). After the pleura was incised in a cephalad direc-tion, the azygos vein and tumor were exposed. For ampu-tating the azygos vein, an EndoWrist stapler was usedthrough the 4th arm port (Figure 3B). The mediastinalfat pad including the tumor was dissected off the superiorvena cava and anterolateral tracheal surface ( Fig-ure 3C and D ) . The resected mediastinal tumor wasplaced in a bag and removed through the assistant port,followed by the insertion of a 21-Fr silicon tube throughthe camera port. The tumor was measured 4.5 × 3.5 ×2.5 cm (Figure 4). Macroscopic finding of the tumor wasyellow-whitish surface.Histopathologically, the resected lymph node was oc-cupied by tumor cells with a solid architecture. The tu-mor cells were large in size and polygonal in shape.Their nuclei were large with a vesicular appearance andprominent nucleoli. The cytoplasm was pale. Based onthese findings, a germ cell tumor, lymphoma, and malig-nant melanoma were considered as differential diagnosticcandidates along with metastatic carcinoma (Figure 5A).Immunohistologically, the tumor cells were positive forcytokeratin (CK) 7, thyroid transcription factor-1 (TTF-1), and napsin A, while negative for CK20, CK5/6, cau-dal related homeobox gene type 2(CDX2, p40, and α-fetoprotein (AFP) (Figure 5B-F). Based on these find-ings, he was diagnosed with metastatic adenocarcinoma,the primary site of which was considered to be the lung.Genetic tests failed to reveal any mutation of epidermalgrowth factor receptor (EGFR) and translocation involv-ing anaplastic lymphoma kinase (ALK) and c-ros onco-gene 1 (ROS1). The postoperative course was uneventful.The chest tube was removed on the 4th day, and he wasdischarged on the 7th day after surgery. Postoperative ad-juvant chemotherapy was received according to the treat-ment for lung cancer. The patient showed no evidence ofrecurrence at the 15-month follow-up.DiscussionCUP refers to metastasized cancer for which the primarysite cannot be identified. This condition is usually seen inthe liver, lungs, and bones. In this case, the mediastinallymph nodes showed isolated metastasis, although it ac-counts for just 1.5% of all CUP involvements.５Mostcommon histological types of CUP are adenocarcinoma,followed by undifferentiated carcinoma and squamouscell carcinoma.１，６Sampling procedures of mediastinal lymph node CUPinclude bronchoscopy, thoracoscopy, mediastinoscopy,and surgical procedures. Differentiating diagnosis be-tween CUP, other tumors originating in the mediastinum,and malignant lymphoma is essential. In addition, sincefuture developments in cancer genome analysis are help-ful for both the diagnosis and treatment selection ofCUP,２sampling of sufficient tumor tissue is important.As a result, biopsy and/or excision of mediastinal tumorsare the best methods.The robotic surgical system provides a 3-dimensionalview and dedicated robotic instruments that have com-―101―Figure　3　The intraoperative screenshot of the robot-assisted thoracoscopic surgery (RATS).(A) The tumor (*) was located in right lower paratracheal lymph nodes (4R) on the cranial side of the azygos vein.(B) After the pleura was incised in a cephalad direction, azygos vein (white arrow) and the tumor were exposed. The azygos vein was amputated by robotic stapler.(C) The mediastinal fat pad including the tumor was dissected off superior vena cava.(D) The mediastinal fat pad including the tumor was dissected off the anterolateral tracheal surface and removed. Figure　4　The intraoperative view of the tumor.The intraoperative view of the tumor was extracted from digital video data taken during the operation and was provided on a per-sonal computer after operation. fortable motions with 7 degrees of freedom in the tho-racic cavity. Although the mediastinum with lymph nodeis tightly packed with intertwined organs, the robotic sur-gical system allowed for a smooth and natural manipula-tion when performing surgical dissection. Especially,compared to the traditional video-assisted thoracic sur-gery (VATS) approach, robot-assisted surgery has beenreported to be more effective for mediastinal lymph nodedissection.７-９Pathologically, seminoma, lymphoma, and malignantmelanoma were considered as differential diagnostic can-didates along with metastatic carcinoma. To determinethe histological type and tumor origin, immunostainingwas performed. Combined immunostainings for CK7 andCK20 are frequently employed to determine the primarysite, especially of adenocarcinoma. TTF-1, SPA, andnapsin A are characteristically positive for lung cancer,especially adenocarcinoma.１０，１１In this case, the primarylesion site was in the lungs because the tumor was posi-tive for TTF-1, CK7, and napsin A but negative forCK20.Although most CUP are considered to signify ad-vanced stage cancers, adjuvant chemotherapy followingsurgical resection is necessary for CUP. For mediastinal―102―Figure　5　Microscopic findings of the resected specimen.(A) Hematoxylin and eosin staining showing desmoplasia in the lymph nodes.(B-F) Immunohistochemical examination revealing positive stain in (B) cytokeratin (CK) 7,  (C) Thy-roid transcription factor-1 (TTF-1), and (D) napsin A, and negative stain in (E) α-fetoprotein (AFP) and (F) CK20. lymph node CUP, there are various postoperative careregimens. A variety of surgical treatments, such as pul-monary lobectomy and lymph node dissection are used.Observation and other treatments, including adjuvantchemotherapy, radiotherapy, or a combination of bothchemotherapy and radiotherapy, are performed after sur-gical resection.３，１２，１３The 5-year survival rate for CUP hasbeen reported to range from 2-6%, but there are also re-ports that isolated mediastinal lymph node CUP has acomparatively better prognosis.１３In some reports, carefulpostsurgical investigation is required for mass shadowsthat appear in the lungs after the excision of mediastinallymph node CUP.４，１４，１５ConclusionRATS tumor resection was performed for mediastinallymph node CUP. In narrow spaces, such as the mediasti-num, RATS is a useful procedure for resectable CUPwith mediastinal metastasis for the diagnosis and estab-lishment of a therapeutic strategy.Conflicts of Interest: The authors confirm no conflicts ofinterest.References1．Briasoulis E, Pavlidis N: Cancer of unknown primaryorigin. Oncologist 2 (3): 142―152, 19972．Vajdic CM, Perez-Concha O, Rhee JJ et al: Health-related predictors of cancer registry-notified cancer ofunknown primary site (CUP). Cancer Epidemiol 61: 1―7,20193．Nakano T, Watanabe H, Takeichi H et al: A case of me-diastinal lymph node carcinoma of unknown primarysite. Tokai J Exp Clin Med 43 (4): 148―152, 20184．Kawasaki H, Arakaki K, Taira N et al: Lung cancer de-tected 5 years after resection of cancer of unknown pri-mary in a mediastinal lymph node: A case report and re-view of relevant cases from the literature). Ann ThoracCardiovasc Surg 22 (2): 116―121, 20165．Holmes FF, Fouts TL: Metastatic cancer of unknownprimary site. Cancer 26 (4): 816―820, 19706．Agca M, Kosif A: Metastatic squamous cell cancer withunknown primary origin in the mediastinal lymph node.Niger J Clin Pract 21 (10): 1384―1386, 20187．Kanzaki M : Current status of robot-assisted thora-coscopic surgery for lung cancer. Surg Today 49: 795―802, 20198．Nasir BS, Bryant AS, Minnich DJ et al: Performing ro-botic lobectomy and segmentectomy: cost, profitability,and outcomes. Ann Thorac Surg 98 (1): 203―208, 20149．Novellis P, Bottoni E, Voulaz E et al: Robotic surgery,video-assisted thoracic surgery, and open surgery forearly stage lung cancer: comparison of costs and out-comes at a single institute. J Thorac Dis 10 (2): 790―798,2018―103―10．Hirano T, Auer G, Maeda M et al: Human tissue distri-bution of TA02, which is homologous with a new typeof aspartic proteinase, napsin A. Jpn J Cancer Res 91(10): 1015―1021, 200011．Chhieng DC, Cangiarella JF, Zakowski MF et al: Use ofthyroid transcription factor 1, PE-10, and cytokeratins 7and 20 in discriminating between primary lung carcino-mas and metastatic lesions in fine-needle aspiration bi-opsy specimens. Cancer 93 (5): 330―336, 200112．Morio A, Miyamoto H, Izumi H et al: A case report ofadenocarcinoma of unknown origin metastatic to the me-diastinal lymph nodes with a review of 21 cases reportedin Japan. Jpn J Lung Cancer 41: 73―78, 2001 (in Japa-nese)13．Riquet M, Badoual C, Le Pimpec BF et al: Metastaticthoracic lymph node carcinoma with unknown primarysite. Ann Thorac Surg 75 (1): 244―249, 200314．Higuchi T, Nagata A, Hamada T et al: A case of primarylung cancer developing 9 years after surgery for metas-tatic mediastinal lymph node carcinoma. J Jpn AssocChest Surg 29: 220―225, 201515．Hayashi K: A case report of a long-surviving patientwith mediastinal lymph node carcinoma from an un-known primary site, with a review of 31 cases reportedin Japan. J Jpn Assoc Chest Surg 21 (4): 624―629, 2007

Robot-Assisted Thoracoscopic Tumor Resection of Lymph Node Metastasis of an Unknown Primary Site: A Case Report

https://twinkle.repo.nii.ac.jp/?action=repository_action_common_download&item_id=25065&item_no=1&attribute_id=22&file_no=1

Robot-Assisted Thoracoscopic Tumor Resection of Lymph Node Metastasis of an Unknown Primary Site: A Case Report

Abstract

Similar works

Full text

Available Versions

Tokyo Women’s Medical University