An Uncommon Case of Primary Synovial Sarcoma of the Lung with a Rare Intraoperative Finding 

Rajashekara Reddy Hosahalli Venkatappa1 and Chemuru Munisekhar Reddy2

1Thoracic surgeon, Sagar Hospital, Bangalore, India

2Department of General Surgery, Sagar Hospital, Bangalore, India

Correspondences to: Dr. Chemuru Munisekhar Reddy; email: chemuru.munisekharreddy@gmail.com

Received: 20 Aug 2021; Revised: 24 Jan 2021; Accepted: 07 Feb 2022; Available online: 20 Sep 2022

Abstract

We report a case of a 32-year-old male who was evaluated for right chest pain and cough with streaky hemoptysis. Chest X-ray and contrast-enhanced computerized tomography scan of the chest showed a large (20x16×16 cm), heterogeneously enhancing mass arising from the right lower lobe. Ultrasound-guided Tru-cut biopsy revealed spindle cell sarcoma. In immunohistochemistry, tumor cells expressed epithelial membrane antigen, CD99, and bcl-2. The final diagnosis of primary pulmonary synovial sarcoma was confirmed after positron emission tomography-computed tomography revealed that the lesion was confined to the right lung. The patient was managed by multimodal treatment. The patient underwent right anterolateral thoracotomy and lower lobectomy with staged systematic mediastinal lymphadenectomy.
Intra-operatively, he was given 2 units of packed red blood cells (RBCs). The patient developed dark-colored urine near the end of the transfusion of the second unit of packed RBCs, but without any hemodynamic instability. All the tests for possible blood transfusion reactions were negative; thus, we concluded that this event was probably secondary to tumor lysis due to the handling of the large primary lesions during surgery.

Key words: Primary synovial sarcoma, lung sarcoma, rare lung tumor, tumor lysis urine

Ann Afr Surg. 2022; 19(4): 212-215

DOIhttp://dx.doi.org/10.4314/aas.v19i4.9

Conflicts of Interest: None

Funding: None

© 2022 Author. This work is licensed under the Creative Commons Attribution 4.0 International License.

Introduction

Soft tissue sarcomas account for less than 1% of the overall human burden of malignant tumors; however, they are life-threatening. The relatively small number of cases and the great diversity in anatomic sites, biologic behaviors, and histopathologic features have made the 
comprehensive understanding of these disease entities difficult. Primary malignant mesenchymal tumors or soft tissue sarcomas originating from lungs are very rare. 
Synovial sarcomas account for 10% of total soft tissue tumors, which are more common in the upper and lower limb regions, but less common in the head and neck regions. Pulmonary sarcomas are very uncommon and comprise only 0.5% of all primary lung malignancies. Primary synovial sarcoma arising from the lung is extremely rare, with very few cases being reported (1, 2). We herein report a case of primary synovial sarcoma of the lung arising from the right lung lower lobe that was successfully managed by a multidisciplinary team (MDT), and the patient was doing well for 24 months after completion of treatment.

Case presentation

A 32-year-old male, nonsmoker, complained of a cough with blood-stained sputum associated with right-sided chest pain for 3 days. There were no constitutional symptoms. Clinically, there was reduced air entry on the right middle and lower zones; otherwise, the rest of the examination was unremarkable. All blood investigations were done, and the values were within the normal limits. Chest X-ray, posteroanterior view, revealed a mass occupying the middle and lower zones of the right chest (Figure 1A), and contrast-enhanced computed tomography (CECT) of the chest (Figure 1B) showed a large (20×16×16 cm), heterogeneously enhancing mass with necrotic areas arising from the right lung lower lobe, with compressive atelectasis of the middle and upper lobed and pressure effect on the mediastinum and displacement of the diaphragm. 


Figure 1.

(A) Chest X-ray (postero-anterior view) mass occupying the middle and lower zones of the right chest. (B) Contrast-enhanced computed tomography of the chest coronal reconstructed image, showing a large, heterogeneously enhancing mass with compression and pressure effect on the mediastinum, right lung, and diaphragm.

Ultrasound-guided Tru-cut biopsy revealed pleomorphic spindle cells with hyperchromatic plump nuclei, scanty cytoplasm, mitosis, 1-2/HPF, and necrosis suggestive of spindle cell malignant tumor. The result of further evaluation with immunohistochemistry (IHC) was suggestive of synovial sarcoma (bcl-2-positive, CD99-positive, EMA-weak positive, CK7-negative, Desmin-negative, S-100-negative, SMA-negative, CD34-negative). The diagnosis of primary synovial sarcoma arising from the right lung was made based on the primary lesion confined to the right lung lower lobe revealed by fluorodeoxyglucose–positron emission tomography (PET). The case was discussed in the tumor board meeting, and the patient received two cycles of neoadjuvant chemotherapy (ifosfamide+doxorubicin-based). Because of increasing symptoms after two cycles, the patient was re-evaluated by PET-CT, showed no significant interval regression in tumor size. He underwent right postero-lateral thoracotomy followed by excision of the mass with right lower lobectomy and systematic staged mediastinal lymphadenectomy. The right upper and middle lobes were not involved and were thus preserved. Two units of packed red blood cells (RBCs) were transfused intra-operatively, but at the end of