[Primary sinus histiocytosis of the trachea: a case report and review of literature]

Abstract

Objective: To study the clinicopathological features, diagnosis and prognosis of primary sinus histiocytosis (Rosai-Dorfman disease, RDD) of the trachea by case report and review of the literature.

Methods: A 63 year old man with a space-occupying lesion of the trachea firstly diagnosed as a malignant tumor was admitted to this hospital for further evaluation and treatment. The lesion was removed by surgery and the final diagnosis was primary RDD. The clinical data of the case was analyzed and the related literatures were reviewed. The literature review was carried out respectively with"Rosai-Dorfman disease" and "sinus histiocytosis"as the key words in Wanfang Med Online and with"Rosai-Dorfman disease","sinus histiocytosis","trachea or lung"as the key words in PubMed database by July 2012.

Results: The chest computerized tomography of the case showed that the mass was located at the right side of the trachea with heterogeneous density and contrast enhancement. Bronchoscopy revealed a neoplasma occluding the distal trachea. The lesion was excised by surgery. Microscopic histology showed that in the dark-staining area a large number of lymphocytes and plasma cells were noted while the light-staining area was formed by giant histiocytes. The pathological changes invaded the tracheal wall and eroded the cartilages. Intact lymphocytes and plasma cells were observed within the eosinophilic cytoplasm of the histiocytes. Immunohistochemistry showed that the giant histiocytes were strongly positive for S-100 protein and CD68 protein. Primary RDD of trachea was confirmed. The patient remained well without any other treatment or evidence of progression for 11 months. A total of 13 literatures and 26 cases were retrieved from Wanfang Med Online and Pubmed, including 21 cases of primary RDD of the upper respiratory tract and 4 cases of primary RDD of the lung. A total of 5 literatures and 5 cases of RDD affecting the trachea were retrieved from Wanfang Med Online and Pubmed. There was only one case of primary RDD of the trachea in Pubmed. A 39-year-old female patient with 1 month of dyspnea was misdiagnosed as having bronchial asthma and was unresponsive to empirical corticosteroid and bronchodilator therapy. The chest computerized tomography revealed an ill-defined irregular soft tissue in the trachea. A tracheal ring sleeve resection and reanastomosis was performed to prevent asphyxia. The mass was confirmed to be primary RDD of the trachea according to histopathology and immunohistochemistry. The patient was well without any treatment for 12 months.

Conclusions: Primary RDD of the trachea is an extremely rare disease, with dyspnoea as a feature of the disease. When it is completely removed, the prognosis is good. Typical histopathology and immunohistochemistry are needed to make a definite diagnosis. The positive immunohistochemistry staining for S-100 and CD68 protein in giant histiocytes and lymphocyteemperipolesis are essential for the diagnosis. The differential diagnosis includes other benign or malignant space-occupying lesions of the trachea.