Pituitary Adenoma Complicated by Acute Bacterial Meningitis in a Patient in Kara (Togo)

Introduction: In the context of pituitary adenoma, bacterial meningitis is a possible complication of surgical or medical treatment. The occurrence of meningitis before any treatment is exceptional, explained by the existence of an osteomeningeal breach caused by the adenoma whose main symptom is rhi-norrhea. Case report: We report a case of bacterial meningitis complicating a prolactin pituitary macroadenoma. The patient had been referred for jet vomiting in a febrile context preceded by headaches and visual blurring. There was no rhinorrhea. The examination revealed a meningeal syndrome and the diagnosis of acute bacterial meningitis was made. The isolated germ was the pneumococcus. Faced with headaches and visual blurring, a cerebral scan revealed a pituitary macroadenoma and pituitary hormone dosage had shown hyperprolactinemia. The meningitis was sterilized and the prolactinoma was treated with dopaminergic agonists. This allowed the normalization of pro-lactinemia and the disappearance of symptoms. Conclusion: The pituitary adenoma was complicated by bacterial meningitis without treatment and the presence of a meningeal breach. Hormonal and bacterial treatments have been successful.


Introduction
Prolactin adenomas or prolactinomas are the most common pituitary adenomas and clinically which are less common in men than in women [1].The prevalence and incidence of prolactinomas are approximately 50 per 100,000 and 3 to 5 new cases/100,000 per year.Prolactinomas in men are larger and more invasive, leading to complications related to the size of the tumor [2].Medical treatment with dopaminergic antagonists is the first-line treatment because of its remarkable efficiency [3].Dopamine agonists are effective in about 80% to 90% of patients with prolactinomas, resulting in reduced serum prolactin levels and tumor size [4].However, surgery can be used in certain situations, namely in patients who do not respond to medical treatment or when there is a large leak of cerebrospinal fluid to the point where surgical repair of the dural defect is essential [5].
In pituitary adenoma, bacterial meningitis is a possible complication of surgical treatment or medical treatment.Meningitis before any treatment is most often exceptional, due to the existence of an osteomeningeal breach caused by the adenoma [6].Indeed, meningitis in a patient with an invasive pituitary macroadenoma is usually due to infection of the cerebrospinal fluid draining through the ruptured skull bone into the sphenoid sinus, allowing entry of nasopharyngeal organisms [7] [8].
In the literature review, we were able to note that pituitary adenoma despite the fact that more and more cases are diagnosed, is still rare.In sub-Saharan Africa, where the technical platform is sometimes insufficient for diagnosis, there are fewer cases.In Togo, Kpélao E et al. [9] were reported 2 cases, one case of gonadotropic adenoma and one case of non-secreting adenoma.In Kara, we did not find any study on pituitary adenomas.Moreover in our practice, this is the first case we have observed and it has seemed appropriate to us to report this case of bacterial meningitis complicating a prolactin pituitary macroadenoma in a patient in Kara (Togo).

Observation
This is a 39-year-old patient with no history, referred from a medico-social center for intense headaches of progressive onset, diffuse and resistant to the usual analgesics and visual blurring evolving for approximately three (03) months associated 24 hours before his admission with vomiting of food in a jet without effort and fever.In addition to the previous symptoms, there was added vertigo, deterioration in general condition (anorexia, weight loss and asthenia) and high blood pressure figures.
The physical examination noted a good state of consciousness, an alteration of the general state, a high fever at 40˚C and a high blood pressure at 160/80mmHg in the 02 arms.There was also a meningeal irritation syndrome (frank neck stiffness, positive Kernig's and Brudzinski's signs), and ICHS syndrome (headaches, vomiting, visual disturbance).
The lumbar puncture had brought back hypertensive and cloudy cerebrospinal fluid (CSF) with a rice-water appearance with, in its cytological study, 7000 white blood cells/mm 3 , predominantly polynuclear neutrophils (85%).Direct examination revealed a gram-positive diplococcus.The chemical examination had noted hyperproteinorachia at 1.89 g/l and hypoglycorachia at 0.72 g/l.The bac-terial culture had objectified the presence of pneumococcus.The C-reactive protein (CRP) was high at 250 mg/l and in the blood there was hyperleukocytosis at 13,300 GB/mm 3 with polymorphonuclear neutrophils at 9600 PN/mm 3 .Faced with this picture of purulent meningitis, the patient was treated with a 3rd generation cephalosporin (Ceftriaxone) at a dose of 4 g per day in 2 IVL doses and oral corticosteroid therapy (Prednisolone 1 mg/kg/day).Faced with the ICHS syndrome, a cerebral CT scan showed an endo and suprasellar pituitary macroadenoma associated with an inflammatory process in the left bilateral and frontal ethmoid-sphenoid-maxillary sinuses without signs suggesting subarachnoid hemorrhage (Figure 1, Figure 2).
A hormonal assessment showed hyperprolactinemia at 455 ng/l.The diagnosis retained was that of acute bacterial meningitis complicating a prolactin pituitary adenoma.Hormonal treatment based on Bromocriptine 15 mg/d was initiated.The patient's condition improved gradually under treatment with the complete disappearance of the meningeal syndrome and other signs.The patient's condition improved gradually under treatment with the complete disappearance of the meningeal syndrome and others signs, and also an improvement of the biological inflammatory syndrome (CRP at 19 mg/l and White bloodcells at 8500 elements/mm 3 ).Prolactinemia fell from 455 to 20 ng/l with a 12-month follow-up.

Discussion
The incidence or prevalence of pituitary adenomas has been the subject of several assessments and at present the data remain conflicting [10].Fontana et al. [10] reported a prevalence of 1/1241 or 0.80‰.In Mali, Bah et al. [11] had found  Generally benign, they are classified according to their size; Micro adenomas are less than 10 mm in size and macro adenomas are 10 mm or larger [14] [15].
There are also mixed (association of two secreting hormone) pituitary adenomas described by some authors [9] [12] [16] [17] [18].Unlike women, who typically have microadenomas, most men have macroadenomas, which would likely be related to delayed diagnosis although there may be sex-specific differences in the biological characteristics of tumors [13] [14].Several authors have reported the macroadenoma in an adult male [5] [18] [19] [20] [21].Our patient's age was 39 years old.The peak incidence of pituitary adenomas occurs in men between the ages of 35 and 60 [10].In the literature the age was variable, but the majority was in the range of 35 and 60 [5] [18] [19] [20].In our patient, the clinical manifestations that were at the forefront of the clinical picture were intense intractable headaches, visual blurring, and jet vomiting in a febrile context.
The most common clinical manifestations of pituitary macroadenomas are endocrine and/or tumor disorders (headaches and loss of vision found in our patient) Margani et al. [5] and N'diaye et al. [16] also reported headaches and blurred vision.More rarely, when a macroadenoma grows towards the base of the skull, it can gradually erode the floor of the saddle and the sphenoid sinus, leading to leakage of cerebrospinal fluid (CSF) causing infection such as meningitis [22].If aseptic meningitis has often been associated with pituitary adenomas in the context of pituitary apoplexy [23] [24], microbial meningitis without rhinorrhea has rarely been reported as a mode of revelation of pituitary adenomas as is the case in our study.To our knowledge, several isolated cases of pituitary adenoma complicated by bacterial meningitis have been reported [5] [27] have resorted to surgical treatment in addition to medical treatment.Although hormone treatment is effective on macro adenomas, there may be treatment failure or recurrence.This sometimes leads to surgery.It can also be in combination with surgery.

Conclusion
Even untreated macroadenomas may present with meningitis without a history of CSF rhinorrhea.The diagnosis of acute bacterial meningitis should be considered at any time in the history of a pituitary adenoma.And it will be necessary to look for a pituitary adenoma in front of any unexplained meningitis.In addition, it is very important to be aware of this rare but dramatic presentation because early and aggressive management can modify the course of the disease.

Figure 1 .
Figure 1.Cerebral CT without injection of contrast product in axial reconstructions showing an pituitary macroadenoma intra and supra sellar compressing the optic chiasma.

Figure 2 .
Figure 2. Cerebral CT without injection of contrast product in sagittal reconstructions and showing an intra and supra sellar tissue process compressing the optic chiasam.
[22]cal treatment with antibiotic and hormone therapy had given good results in our patient, this result is similar to those of Margani and Akkache[5] [25]; This would theoretically increase the susceptibility to developing meningitis in the macro adenoma.Medical treatment based on antibiotic therapy and hormone therapy has given good results[5] [25]which was the case in our patient; some authors[6][9][15] [19] [20][21][22]