Fatty tissue within the maxillary sinus: a rare finding.

Clinical data of the patient was analysed retrospectively. The patient presented with symptoms of left-sided chronic maxillary sinusitis and had undergone several punctures of the left maxillary sinus 18 months earlier. Subsequent to one of the procedures an acute pain in the left orbit lasting a couple of days was noted. Left endoscopic transnasal antrotomy was performed. The maxillary sinus was filled with polypous, chronically inflamed mucous membrane. Upon its removal, the maxillary roof was identified as drawn downwards and covered with normal mucous membrane. Upon dissection of the membrane, adipose tissue filling the zygomatic recess of the sinus was identified and subsequently removed. The maxillary roof was unchanged. Histopatologic examination confirmed the material to be adipose tissue. No short or long term sequelae occurred.Adipose tissue can be found in the maxillary sinus most commonly when penetrating from surrounding locations. It is our hypothesis that in the reported patient it penetrated from the orbit to the maxillary sinus following puncture. It seems that a hole in the maxillary sinus roof, about 1 mm in diameter, caused by the needle, may have been a portal of entry for the adipose tissue into the maxillary sinus. The discussed case suggests particular care be taken in performing puncture of the maxillary sinus.Orbital content herniation into the maxillary sinus is relatively frequent in orbital floor fractures [1]. Soft tissues (inferior rectus muscle and orbital fat) penetrate through the cracks in the orbital floor which results in limited eye movements and diplopia [1]. Magnetic resonance imaging (MRI) is able to demonstrate orbital floor fractures as sensitively as computed tomography (CT), but CT is superior to MRI in showing small and associated fractures; therefore CT remains the imaging modality of choice in the case of orbital fractures and dehiscences [1,2]. Both MRI and CT are not effective in differentiating adipose tissue from o