Primary malignant melanoma of the trachea is uncommon. Only six cases have been reported worldwide. A patient who underwent a tracheal resection for this rare pathology is presented.
The patient is a 64-year-old male smoker who presented with cough and hemoptysis. He did not have any symptoms of airway obstruction. Initial investigation was performed in a community hospital. A flexible bronchoscopy demonstrated a lower obstructing tracheal tumor. Biopsies showed malignant cells. Computed tomographic scan of the chest and upper abdomen demonstrated the tracheal tumor.There were no enlarged lymph nodes or evidence of metastases. A bone scan and an abdominal ultrasound were normal. Pulmonary function test were consistent with large-airway obstruction.The patient was transfered to our institution and taken to the operating room. Under general anesthesia the patient was intubated with a single lumen tube and a flexible bronchoscopy was performed. The mass was seen to occlude three quarters of the lumen of the distal trachea. The tumor was polypoid and had a pedicle, which was attached about three centimeters above the carina, on the right lateral wall. The surface of the mass was very smooth and pink in color. The tumor was removed to provide relief of the airway obstruction. An endoscopic snare, with electrocautery, was used to divide the pedicle. The mass was then snared and removed together with the endotracheal tube. The patient was discharge home the following day.The pathology was reported as melanoma. It was a 1.9 cm polypoid tumor. Within the subepithelial tissue were nests and sheets of epithelioid cells. Mitotic figures were numerous. Granular brown pigment were identified in occasional epithelioid cells and in adjacent histiocytes. Immunohistochemestry showed strong positive staining of the epithelioid cells for S 100, HMB45, and melan-A.The patient was brought back electively to the operating room for a tracheal resection to remove the residual tumor base. A flexible bronchoscopy showed residual melanotic tumor at the site of the pedicle, and two adjacent satellite nodules. A right thoracotomy was performed. Injection of lymphazurin (isosulfan blue) into the tracheal wall was done to locate a sentinel node. Frozen section of this node revealed no metastatic melanoma. The tracheal resection was performed removing four tracheal rings. The patient was discharged home, uneventfully, on the seventh post-operative day.The pathologic analysis of the resected trachea confirmed the presence of residual melanoma. No benign junctional melanocytes were demonstrated.DISCUSSION: Primary melanoma of the trachea is an extremely rare condition. The pathological appearance may or may not suggest a primary versus a metastatic tumor. Therefore, it is mandatory to complete a careful physical examination of all potential primary sites. We were satisfied no other primary site existed in this patient.The tumor, at initial presentation, was almost completely obstructing the distal trachea. Although it was first biopsied by flexible bronchoscopy under mild sedation, this is not recommended because of the potential for bleeding and ensuing complete airway obstruction. It is recommended that the patients with an obstructing tracheal tumor be managed in the operating room, with a rigid bronchoscope available.Sentinel node localization is the standard of practice for intermediate risk cutaneous melanoma. This report describes the first attempt at utilizing this for a tracheal neoplasm. It will require further study as to its applicability.
Primary malignant melanoma of the trachea is very rare. Tracheal resection is the treatment of choice for localized tumors.
C. Sirois, None.