喉頭に原発したCellular fibrous histiocytomaの一例

抄録

Fibrous histiocytoma is a tumor mainly that occurs in the limbs and soft tissue, and rarely occurs in the head and neck region. We experienced a case of cellular fibrous histiocytoma of the larynx. The patient was a 36-year-old man who had complained of hoarseness. A hemorrhagic tumor was detected at the left subglottis by laryngoscopy. We initially suspected subglottic inflammatory granulation and treated the patient conservatively; however, this was ineffective. We performed microscopic laryngeal surgery for diagnostic and treatment purposes. A histopathological examination of the resected tumor, revealed spindle cells with a narrow nucleus and acidophilic cytoplasm that proliferated tightly in the tumor tissue. The number of mitotic cells was 6/10 high power field and the tumor was negative for malignancy. On immunostaining, most tumor cells were positive for CD68 and CD163, the histiocytes were positive for S-100, while staining of CD34 and α-smooth muscle actin was negative. Thus, the diagnosis was cellular fibrous histiocytoma. The tumor recurred after ten months, we performed transoral surgery with CO₂ laser, which is useful for coagulation and resection. No recurrence was detected at two years after the second surgery. To our knowledge, there are no previous reports of cellular fibrous histiocytoma of the larynx.