Frontal Sinusitis with Mixed Bacterial Colonies Treated with the Combination of Endoscopic Modified Lothrop Procedure and External Approach

Isolated frontal sinusitis with mixed bacterial colonies is extremely rare and has not been described. We report a case of isolated frontal sinus forming mixed bacterial colonies that occurred in the previously exposed frontal sinus. The material in the frontal sinus was macroscopically similar to sinus fungus ball. Surgical strategy followed that for sinus fungus ball. The material could not be completely removed even with an endoscopic modified Lothrop procedure (Draf type III procedure). Additional external incision enabled complete removal of the remnant infectious substance. Histological examination detected two different types of organisms as intermingled bacterial colonies. External approaches to the frontal fungus ball have recently been replaced by the endonasal approach. Our case suggests that material trapped in a pit or small crevice in a frontal sinus may not be removed intranasally. 1. Introduction Most cases of frontal sinusitis are caused by drainage congestion as a consequence of the complex anatomy of the frontal recess, but the infection may also spread via normal anatomical fissures or fracture lines [1]. The standard treatment technique for chronic frontal sinusitis is endoscopic removal of the uncinate process, ethmoid bulla, and common wall between the frontal sinus, the agger nasi cell, and supraorbital cell. Failure to achieve adequate removal of these walls may result in chronic edema and frontal sinus obstruction may develop [2]. The contents of the frontal sinus are mucous, pus, or mucin and can be removed with malleable suction or irrigation. Sinus fungus ball is a form of fungal sinusitis which is defined as a noninvasive chronic fungal sinusitis without inspissated allergic mucin. Sinus fungus ball occurs in immunocompetent hosts and endoscopic surgical treatment usually results in good outcome. Sinus fungus ball occurs most commonly in the maxillary or sphenoid sinuses [3, 4]. The standard treatment of fungus ball is complete removal of the fungus and wide opening of the ostium of the diseased sinus. Fungus ball of the frontal sinus is extremely rare, with fewer than 40 cases reported in the English literature [5, 6]. The surgical procedure is more difficult than those used in the maxillary and sphenoid sinuses because the possible maximum opening in the case of frontal sinus is relatively small [7]. Previously, almost all cases were treated with an external approach [5]. Recently, with the development of new instruments and innovations in endoscopic techniques, the Draf type III/endoscopic modified Lothrop procedure