A 32-year-old woman.
She was admitted for anal pain of one week of evolution and fever of 39.9 °C. At the initial examination, a painful rectal examination revealed the presence of a bulging in the left region of the rectum.
The initial diagnostic suspicion is a rectal submucosal abscess.
The patient reported improvement of anorectal pain after spontaneous removal of purulent fluid.
She was admitted with antibiotic treatment (metronidazole and tobramycin).
In the first two days, the patient presented progressive deterioration, headache, nausea and somnolence.
Acute meningitis was diagnosed with 1,500 MBN leukocytes per mm3 in cerebrospinal fluid.
Gram stain and culture are negative due to previous antibiotic treatment.
Pelvic CT scan revealed sacral dysplasia with incomplete closure of the last anterior arches, and an abscess at the bottom of the Douglas sac.
Lumbosacra MRI shows that it is an anterior sacral meningocele that herniates through the anterior sacral bone defect of 9 x 6 x 5 cm and displaces pelvic structures.
1.
A rectoscopy was subsequently performed, which showed rectal imprint of the meningocele, with preserved mucosa except at a small depressed point and covered with fibrin suggestive of a fistulous orifice.
An endoscopic ultrasound showed thickening of the submucosa, as well as meningocele.
The patient was operated anteriorly, releasing the sac, fixing it and closing the neck orifice with suture, muscle fascia and tisucol.
The meningocele recieved it at 8 months, because it had to be reoperated, posteriorly, to reinforce the walls of the dural sac without new recurrence.
Anterior sacral meningocele is a type of occult spinal dysraphism.
Part of the tecal sac is herniated through an anterior sacral bone defect.
Clinically, it is expressed by the pressure exerted on the pelvic organs, causing chronic pelvic heaviness, urinary dysfunction andmenorrhea, and other symptoms are related to involvement of the roots dys constipation (1).
1.
Due to its relationship with the posterior rectal face, its presence can be easily detected.
However, due to its rarity, it is not thought of as a diagnostic possibility in the initial moment.
This can result in inadequate diagnostic or therapeutic techniques, such as puncture, which can lead to fatal meningitis (2,3).
Bone defect on the anterior surface of the sacrum, visible with a simple sacral radiograph and pelvic CT, is the cause of suspicion.
It is confirmed when objectifying the communication of the cyst sac with the spinal subarachnoid space, with magnetic resonance or CT myelography.
The same embryological defect can also cause developmental disorders of the skin and internal organs (atresia/ anal stenosis, duplication of the uterus or vagina, etc.).
It is also associated with the presence of other pelvic tumors such as teratomas, hamartomas or dermoid cysts, with which differential diagnosis must be made (1.4).
Less frequently, the presentation of anterior sacral meningocele is as acute polybacterial meningitis (5-7).
This complication is severe and requires early diagnosis and treatment.
Some cases are related to aspiration or perforation maneuvers.
When it is spontaneous, usually no fistulization with the rectum is demonstrated, although its origin is suspected to be in a contamination from the gastrointestinal tract.
We found only two published cases with rectal fistula (5.8), as in the case presented.
The treatment is surgical, because there is no spontaneous regression, and there is a high risk of meningitis (9.
The surgical technique consists of closure of the sac after meningocele aspiration in a strict aseptic environment.
In summary, this rare cause of rectal compression should be suspected in the presence of a sacral bone defect, which may be visible on a simple sacral radiograph.
Signs and symptoms of local inflammation with onset of meningitis are complications that should be diagnosed and treated early.
M. T. Diz-Lois Palomares, J. Souto Ruzo, J. A. Yáñez López, M. A. Vázquez Millán, J. M.
Gastroenterology Service and 1 General Surgery Department B. Juan Canalejo University Hospital Complex.
A Corunna
