Bilateral cysts of the fossa of Rosenmuller

Case contributed by Dr Sathiyaseelan Maniharan


Referred for MRI scan of brain with the history of recurrent complex partial seizure. This is an incidental finding.

Patient Data

Age: 52 Years
Gender: Male

The MRI scan of the brain demonstrates bilateral tubular lesions in the well defined cystic mass lesions in the fossae of Rosenmuller, measuring 2 x 1 cm  and 3 x 1.5 cm in size on the right and left sides respectively. The lesion in the left side bulges into the nasopharynx. The right sided lesion has high signal intensity in T1 W low signal intensity on T2W image. The left sided lesion has low signal intensity in the T1W image and high signal on T2W & FLAIR images respectively.

Appearances are that of mucous retention cysts in the bilateral fossa of Rosenmuller.

Case Discussion

The fossa of Rosenmuller are posterolateral recesses of the nasopharynx, which is the site of origin of up to 50% of nasopharyngeal carcinomas [1]. Cystic lesions of the nasopharynx are rare but it is essential to differentiate two entities, as they have totally different clinical course and management.

Differential diagnosis of cysts in the fossa of Rosenmuller is somewhat different from the of midline lesions:

  • mucous retention cysts (66%)
  • intra-adenoid cysts
  • oncocytic cyst
  • bronchial cysts

Tornwaldt's cyst presents in the midline within the nasopharynx [3].

The highest prevalence of mucous retention cyst is found in the age group  41-50 [2]. There is further, a significant  correlation between human immunodeficiency virus infection and mucous retention cysts [2].

Contributed by Dr. (Mrs) Tamara Rajapakse and Dr. S. Maniharan.

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Case information

rID: 30450
Published: 14th Aug 2014
Last edited: 16th Sep 2015
System: Head & Neck
Inclusion in quiz mode: Included

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