A 58-year-old man presented to us three years ago with a history of progressive anterior neck swelling and hoarseness of voice for the past one month. On clinical examination, there was palpable left anterior neck swelling with cervical lymphadenopathy. A core needle biopsy of the lesion revealed invasive poorly differentiated carcinoma. He defaulted our follow-up and opted for a left hemithyroidectomy at another institution. The histopathological report was intrathyroid thymic carcinoma. He refused adjuvant radiotherapy despite being counselled and subsequently defaulted follow-up.\nRecently, the patient presented to us again with progressive hoarseness of voice and intermittent haemoptysis. He had shortness of breath, especially when lying flat, but no difficulty in swallowing. On clinical examination, there was a left supraclavicular mass measuring 2 × 2 cm. The mass was immobile and hard in consistency. The anterior aspect of the neck showed an irregular hard mass measuring 3 × 4 cm. An indirect laryngoscopy examination revealed a left vocal cord palsy, likely from his previous presentation. An intraluminal mass was seen over the posterior tracheal wall, occupying a third of the tracheal lumen. We proceeded with a contrasted computed tomography (CECT) of the neck and thorax, which revealed a lobulated hypodense soft tissue mass measuring 4.3 × 3.9 × 5.2 cm. It occupied the left thyroid bed from the C7/T1 to the T2/T3 vertebral level, with left retrosternal extension and tracheal deviation to the right. The soft tissue mass had displaced the left common carotid artery and internal jugular vein laterally. As the CECT showed (, ), the soft tissue mass had caused more than 80% of tracheal luminal narrowing. At retrosternal, multiple matted lymph nodes were seen.\nImage-guided fine needle aspiration cytology (FNAC) of the soft tissue mass at the left thyroid bed showed malignant cells suggestive of intrathyroid thymic carcinoma (CASTLE). After a multidisciplinary meeting, we planned for curative resection and tracheostomy. Intraoperative tracheoscopic examination showed a soft tissue mass measuring 3 cm in length at the posterior tracheal wall, 2.1 cm from the vocal cord (). The mass was debrided to achieve an adequate diameter of tracheal lumen distal to the tracheostomy insertion. The left supraclavicular solid tumour densely adhered to the left great vessels. Due to a high risk of injury to the great vessels, we proceeded with tumour debulking only.\nThe histopathology report showed an unencapsulated tumour that displayed lobular architecture. The tumour lobules were composed of sheets of neoplastic polygonal cells rimmed by a variable amount of mature lymphocytes. The neoplastic cells were mildly pleomorphic, and lymphovascular invasion was present. Skeletal muscle bundles attached at the periphery showed focal tumour cell infiltration (, ). Immunohistochemical studies were immunoreactive for CD5 (membranous pattern) and CD117 but negative for thyroglobulin and TTF1 (, ). The proliferative index, Ki67, was approximately 20%.\nPostoperative care was unremarkable, and no immediate complications were noted. The patient was counselled for adjuvant chemoradiotherapy, but he was not amenable to this course of action. He is currently under regular follow-up with no disease progression six months after the operation.
A 52-year-old woman was referred to our hospital because of severe dyspnea and the presence of a neck tumor. She had experienced dyspnea for the past 6 months and had recently noticed bloody sputum. A computed tomography examination of the neck revealed a thyroid tumor about 8 cm in size. The tumor had invaded the trachea, obstructing 90% of the tracheal lumen (fig. ). An emergency tracheotomy was performed to maintain an airway through the tumor tissue. On biopsy, the tumor was diagnosed as CASTLE, suggesting a favorable prognosis if a complete resection could be performed. Magnetic resonance imaging and an esophageal fibroscopy examination revealed a low possibility of esophageal invasion (fig. ). Under general anesthesia, a thyroidectomy was initially performed via a neck incision. The invaded portion of the trachea was sharply dissected. A partial sternotomy was performed at the level of the 2nd intercostal space to identify the distal portion of the intact trachea and to mobilize the inferior tracheal segment. The trachea was transversely opened to find the intact portion. The length of the resected trachea was 6 cm (fig. ). Bilateral recurrent nerves were macroscopically preserved. We performed a suprahyoid release to mobilize the superior tracheal segment, but these mobilizations were insufficient to perform an anastomosis. Thus, to allow additional mobilization, we performed a clamshell thoracotomy and incised the pericardium 360° around the hilum, dissecting the pulmonary ligament bilaterally. These procedures allowed an anastomosis. An end-to-end bronchial anastomosis was carried out using running 4-0 PDS II sutures (Ethicon, Somerville, N.J., USA) for the membranous portion and interrupted 4-0 PDS II sutures for the cartilaginous portion. The bronchial anastomosis was wrapped with an omental pedicle flap that was lifted up through a retrosternal route via a laparotomy. A gastrostomy was also performed for postoperative enteral nutrition. For management after surgery, a chin suture was placed. Neck mobilization was restricted for the placement of the chin suture and airway fixation. After confirming an improvement in the laryngeal edema using a laryngoscopy, extubation was performed on postoperative day (POD) 17. The patient exhibited swallowing disturbances and underwent swallowing rehabilitation. Enteral nutrition was provided through the gastrostomy. The patient was discharged on POD 31, and per os feeding was started on POD 51. Radiotherapy (60 Gy in 40 daily fractions of 1.5 Gy) was performed as an adjuvant therapy. Throughout the clinical course, no major complications, including swallowing disturbances, hoarseness or anastomotic problems, were observed. A histopathological examination of the resected specimen revealed the characteristic morphology of CASTLE (fig. ); immunohistochemistry was positive for CD5 (fig. ) but negative for thyroid transcription factor 1 (TTF-1; fig. ).\nEleven months after surgery, lower back pain and right leg numbness developed and led to gait inability. Multiple lung and bone recurrences were observed, but no local recurrence. In order to ease the back pain, palliative radiotherapy (35 Gy in 14 fractions) to the bone metastasis was administered. Twelve months after surgery, drainage of pleural effusion was performed. She died of pleural metastasis 14 months after the initial diagnosis of CASTLE.