A teenaged girl was evaluated for loss of smell with a probable duration of years, but she was uncertain about exact duration. Her parents stated that at the age of 3 years she sustained minor trauma to her nose while at a playground but that she had not experienced any major head trauma. The patient had a history of frequent cough and congestion, seasonal allergies, monthly migraine headaches, and considerable nose congestion at night. She did not recall a history of recurrent sinusitis, snoring, or mouth breathing. Her family history was otherwise normal and did not include any pattern of familial anosmia or delayed puberty. She reported the ability to detect very strong odors but not subtle ones. She was even unable to smell smoke at times. Physical examination revealed a clinically significant hump on the dorsum of the nose consistent with minimal prior trauma, but no other abnormal findings. The patient failed the Penn smell tests, correctly identifying only 3 of the 11 smells. Flexible fiber-optic examination of the nose revealed no masses, polyps, or cysts. A magnetic resonance image of the anterior skull base demonstrated absent olfactory sulci (OS) and bilateral olfactory grooves containing minimal tissue (Figure, A, yellow arrowheads). The Figure, B, depicts normal OS (pink arrowheads) and bulbs (yellow arrowheads) from a different patient for comparison.