A 26-year-old non-smoker female with no medical comorbidities and no relevant family history, who was having a cough for 3 months, presented to the emergency room with progressively increasing stridor. The patient was acyanotic and was having tachypnea with labored breathing. Chest X-ray was suggestive of right lung collapse. The computed tomography (CT) scan of neck and chest (done outside before presentation to our institute) demonstrated a 20 × 17 mm tracheal mass just proximal to the carina, on the right posterolateral side, occluding the tracheal lumen with no extraluminal extension. There was no regional lymphadenopathy or distant metastasis (Fig. 1a–d).
Evaluation with fiber optic bronchoscopy (FOB) was done to assess the nature and extent of disease along with the feasibility of therapeutic debulking/coring. On bronchoscopy, there was an exophytic sessile obstructing ulcero-proliferative growth of size approximately 2 × 2 cm just proximal to the carina and extending for 2.5 cm above it. Tumor coring was facilitated with a rigid bronchoscope under sedation (Fig. 2a–d). Histopathology of the debulking specimen was suggestive of neuroendocrine carcinoma, being focally immunopositive for pancytokeratin and synaptophysin, while immune-negative for chromogranin and TTF-1. Ki-67 labeling index was 20–30% in the highest proliferation area.
After symptomatic improvement with debulking, the patient was planned for definitive surgery two weeks later. Vitals parameters were in the normal range. Her general and systemic examination findings were essentially normal, except for respiratory system evaluation; there were decreased breath sounds on the right side with focal crepitations. Hematological work-up was normal. Post-tumor debulking/coring, Pulmonary function test (PFT) demonstrated forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) 2.07 L (75% of predicted) and 3.28 L (94% of predicted) respectively.
The surgery was planned through the right postero-lateral muscle-sparing thoracotomy approach along the fourth intercostal space using isolated left lung ventilation on total intravenous anesthesia. Intraoperatively, there was an ulcerative tumor of size 1.5 × 1.0 × 1.0 cm in the right posterolateral wall of the trachea, starting just proximal to the carina and extending 2 cm above it. There was no paratracheal extension. The patient underwent tracheal resection with subcarinal and paratracheal lymphadenectomy with tracheoplasty after inferior pulmonary ligament release and hilar mobilization. The trachea was adequately mobilized on anterior and posterior aspects to facilitate tension-free tracheoplasty and the tracheal defect of ~ 3 × 2 cm was closed in transverse fashion using 4–0 interrupted absorbable monofilament sutures. Primary tracheoplasty was augmented with the pericardial fat pad. After the procedure, check FOB was done to ensure airtight closure. The patient was discharged on the fifth day of surgery after uneventful recovery. There were no early or late surgical morbidities.
Histopathological specimen comprised grossly of a fragment of the cartilage of size 1.5 × 1.0 cm with attached tumor tissue 1.5 × 1.0 cm (Fig. 3). The cut surface of the tumor was yellowish-white. Sections from the tumor revealed a small round cell tumor arranged in sheets. All resected margins (anterior, inferior, subcarinal, and right lower paratracheal) and dissected 3 lymph nodes adjacent to the main specimen were free of tumor. Immunohistochemically, tumor cells were immune-positive for EMA, BCL2, MIC-2, and TLE1, while immune-negative for TTF-1, chromogranin, desmin, and myogenin. MIB-1 index was around 50–60%. Overall morphological and immune-histochemical features were favoring synovial sarcoma with a differential diagnosis of Ewing’s sarcoma (ES). Fluorescence in situ hybridization (FISH) analysis for SS demonstrated dual-color break-apart rearrangement probe (Vysis) which indicates t(X;18)(p11.2;q11.2), reciprocal translocation between SS18 gene on chromosome 18 (18q11.2), and SSX gene on chromosome X (Xp11.2) causes the presence of SS18-SSX fusion gene (Fig. 4). FISH analysis for ES did not show dual-color break-apart rearrangement probe (Vysis) which indicates the absence of t(11;22)(q24;q12), translocation between EWSR1 gene on chromosome 22 (22q12), and FLI-1 gene on chromosome 11 (11q24) causes the EWSR1/FLI-1 fusion gene. Based on these histological, immunohistochemical, and molecular genetic analyses, a final diagnosis of synovial sarcoma of the trachea was considered.
Because of small-sized primary tracheal synovial sarcoma with negative margins dissection, no adjuvant treatments were advised in a multidisciplinary tumor board meeting. The patient was kept on follow up with clinical examinations and serial chest X-ray and FOB. One year after surgery, there was locoregional control and had no distant metastases in chest X-ray imaging (Fig. 5).