Objective To investigate the clinical characteristics and management of pituitary abscesses. Methods The clinical characteristics and management of 6 cases of pituitary abscesses confirmed by pathology since August 1998 to August 2007 were retrospectively studied. Results Six patients were admitted seven times, one case was misdiagnosed as pituitary tumor preoperatively, two were highly suspected, and four were clearly diagnosed preoperatively. All six cases underwent single nostril pituitary abscess resection, and three of them applied nasal endoscopy, with no recurrence at 6 months~2 years of follow-up. Conclusion Preoperative clear diagnosis and active surgical treatment are the key to treat pituitary abscesses, and the application of nasal endoscopy is promising.
Pituitary abscess (PA) is very rare clinically, accounting for about 0.3%~0.5% of saddle area tumors1, and preoperative diagnosis is difficult. In this paper, we retrospectively analyzed six cases of pituitary abscess diagnosed by pathology since August 1998 to August 2007 to discuss the clinical features, diagnosis and surgical treatment of pituitary abscess.
Materials and methods
I. General data
From August 1998 to August 2007, 6 cases of pathologically confirmed pituitary abscesses were admitted, including 2 males and 4 females, aged 15-60 years, with an average age of 34.5 years. The duration of the disease ranged from half a month to 5 years (see Table 1).
II. Clinical manifestations
Four patients had fever before surgery, with a maximum of 39°C and a minimum of 38.5°C. The history of the disease was from half a month to 4 months, and one case had a clear history of pterygoid sinus infection, which had been diagnosed outside the hospital, while the remaining three cases did not have a clear history of infection, but only had fever as the first symptom, accompanied by different degrees of headache, malaise, nausea and vomiting. One case was admitted to neurosurgery with visual field defect, one case was accompanied by menstrual irregularities in addition to fever; two cases had visual loss as the main symptom, with a medical history of 1 year and 5 years, respectively.
Imaging performance
All 6 patients underwent MRI examination. 3 cases showed enlarged pituitary gland with iso-T1 iso-T2 signal, clear boundary, uniform internal signal, and no obvious enhancement; 2 cases showed typical circumferential enhancement, one of which showed iso-T1 iso-T2 uniform signal, and the other showed inhomogeneous signal (see Figure 1); one case showed short T1 and long T2, clear contour, irregularity, and obvious enhancement.
Figure 1: MRI film of case 3
Enlarged pituitary gland, inhomogeneous signal within the pituitary gland, and obvious circumferential enhancement (irregular circumferential enhancement within the pterygoid sinus as a thickening of the infected mucosa of the pterygoid sinus)
IV. Surgical treatment
All 6 cases were treated by single nostril pituitary abscess resection, 3 early cases were treated by microscopy, and 3 recent cases were treated by direct nasal endoscopy, and those diagnosed or highly suspected were treated as early as possible, and antibiotics were applied during the perioperative period with good results. One case was discharged from the neurology department after 3 months of conservative treatment with fever and headache, and was again admitted to the neurosurgery department for surgery with fever and polydipsia. 4 cases had thinning of the saddle base bone and high dural tension, and 1 case had destruction of the bone and dura and pus flowing into the pterygoid sinus, resulting in thickening of the mucosa of the pterygoid sinus. In the five cases where the dura was intact before incision, puncture aspiration was performed, and yellow-white pus was extracted in three cases. in two cases, the abscess cavity was not completely formed, and after incision of the dura at the base of the saddle, gray-white soft necrotic tissue was seen mixed with a small amount of pus, and blood flow was not abundant. During the operation, pus or necrotic tissue was taken for bacterial culture, and the pus and pus cavity were carefully cleared; the mucosa and part of necrotic bone of the pterygoid sinus were cleared if there was inflammation of the pterygoid sinus; saline, 3% hydrogen peroxide solution and gentamicin solution were repeatedly flushed, and gelatin sponge soaked with gentamicin solution was used to fill the saddle and pterygoid sinus. The nasal cavity was not filled in the three most recent cases with nasal endoscopy. The culture found pathogenic bacteria in 3 cases, including 2 cases of Staphylococcus aureus and 1 case of Streptococcus griseus, while the remaining 3 cases did not have pathogenic bacteria.
Results
There was no recurrence at 6 months to 2 years of follow-up. The symptoms disappeared in 4 cases with fever as the main complaint. In 2 patients with decreased visual acuity, the remission was not obvious in the one with a long history of disease (5 years), and the visual acuity improved significantly in the other case (1 year); the urine volume was still slightly but significantly decreased in 1 case with polyuria, and menstruation returned to normal after 3 months in 1 patient with menstrual irregularities.
Discussion
I. Etiology.
Pituitary abscesses are rarely seen clinically, and the cause of their formation remains unknown. Relevant literature reports that its etiology can be divided into two categories: primary and secondary 2:
(1) primary: the spread of inflammatory lesions of hematogenous or adjacent structures, such as meningitis, pyogenic pteroid sinusitis, cavernous sinus thrombophlebitis, etc;
②Secondary: often secondary to lesions in the saddle area such as pituitary adenoma, craniopharyngioma, Rathke’s cyst, or even secondary to pituitary tumor resection, and a significant proportion of them cannot be found.3 Pituitary abscesses have a wide spectrum of pathogenic bacteria, the same as abscesses in other parts of the skull, including G+ cocci, G-cocci, anaerobes, and fungi and yeasts, of which G+ cocci are the most common.4,5 In this group of cases The culture found pathogenic bacteria in 3 cases, including 2 cases of Staphylococcus aureus and 1 case of Streptococcus griseus. The remaining three cases did not have pathogenic bacteria, which may be related to the application of preoperative antibiotics and imperfect culture conditions, which is also consistent with the relevant literature.6
II. Diagnosis.
Because of the special lesion site, it is difficult to confirm the diagnosis before surgery and often leads to misdiagnosis. In this group of 6 cases, there was one case of preoperative misdiagnosis of pituitary adenoma and two cases of high suspicion. The reasons for the difficulty in diagnosis were mainly due to:
(1) low morbidity. Only 6 cases were confirmed by surgery during 9 years in this group, so clinical workers lacked vigilance and awareness of this disease.
(2) Lack of obvious specificity of symptoms. Among the 6 cases in this group, there were 2 cases without obvious febrile symptoms, and one of the misdiagnosed cases only showed decreased visual acuity.
(3) Typical imaging manifestations are rare. There have been reports of misdiagnosis of pituitary stroke.7 Most of them only showed enlarged pituitary gland with variable MRI signal, and a few resembled cystic pituitary tumor or craniopharyngioma, which increased the difficulty of diagnosis. Analyzing the cases in this group and referring to various reports7, the author believes that pituitary abscesses should be highly suspected in the presence of.
(1) Those with a history of recurrent fever with or without a history of infection in adjacent sites, especially in adults with cystic tumors in the saddle area.
(2) Suspected or confirmed pituitary tumors combined with significant uveitis symptoms.
(3) CT shows a circular, low or slightly hypointense, round-like occupying lesion with clear borders in the saddle or suprasaddle; MRI shows an enlarged pituitary gland with clear borders of short T1, long T2 homogeneous signal mass, or long T1, long T2 signal and equal T1, long T2 signal with typical circumferential enhancement.
(4) PA can cause hypopituitarism and decrease hormone concentration due to destruction and compression of pituitary tissue, while functional pituitary adenomas secrete various pituitary hormones and increase hormone concentration, so endocrine examination can be used as one of the differentiation points at the onset.
(5) Bacterial meningitis, especially septic meningitis, coexists with suspected or confirmed pituitary tumors.
(6) Previous skull base fracture with CSF nasal leak, with optic cross syndrome or endocrine dysfunction.
(7) Imaging suggests extensive destruction of the saddle base, exudation in the pterygoid sinus especially the mucosa of the pterygoid sinus is enhanced, and combined with smaller lesions in the saddle area.
Third, surgical treatment.
Early diagnosis, early surgery and proper antibiotic treatment are the key to treat pituitary abscess, and all six cases in this group were treated by surgery. At present, transsphenoidal surgery is respected by most scholars8, and we carried out transnasal endoscopic single nostril pituitary abscess excision on this basis. After synthesizing various reports9,and combining our own experience, we believe that the following points should be noted for this operation.
(1) Early surgery should be performed when the diagnosis is clear or highly suspected
(2) Perioperative antibiotics should be used in the preoperative period
(3) Intraoperative puncture and aspiration should be performed before opening the dura to further clarify the diagnosis
(4) Dural opening should be as large as possible to facilitate drainage and removal of the cyst wall
(5) Try to completely remove the abscess wall
(6) Avoid damage to the saddle septum, which may cause cerebrospinal fluid leakage and intracranial infection
(7) In case of combined pterygoid sinus infection, remove the mucosa of the pterygoid sinus and the invaded bone as thoroughly as possible
(8) Repeatedly flush the surgical area with hydrogen peroxide, antibiotics and saline
(9) Intersaddle and pterygoid sinus filled with gelatin sponge infiltrated with antibiotic solution (
(10) Followed by postoperative antibiotics. Some scholars advocate the application of 3 to 4 weeks10, we generally grasp in about 2 weeks, the effect is good. If the pathogenic bacteria and sensitive antibiotics can be detected, they can be selected.
(11) Because patients mostly have endocrine hypofunction, a small amount of hormone can be applied routinely after surgery. We believe that compared with the traditional microscope, the nasal endoscope has the advantages of good illumination, direct vision, no dead angle, and no need for postoperative caulking, etc. Its prospects are broad, but it also puts forward higher requirements for the coordination ability of the operator’s hands.
IV. Postoperative complications.
Domestic Tao Wei et al11 reported that 42.2% of postoperative hyponatremia occurred, and Zhang Minsheng et al12 reported that pituitary adenoma was found to recur after pituitary abscess surgery. 4 cases with fever as the main complaint in this group showed disappearance of symptoms, 2 patients with decreased visual acuity, the long history (5 years) showed insignificant remission, and the other case (1 year) showed significant improvement in visual acuity, 1 case with polyuria still had slightly more urine but significantly reduced, and 1 patient with menstrual irregularities had 3 postoperative One patient with menstrual irregularities returned to normal after 3 months of surgery, and there was no recurrence after 6 months to 2 years of follow-up without significant complications, which may be related to the small number of cases and short follow-up time.
The literature reports that the mortality rate of large tumors in the saddle area combined with untreated pituitary abscesses is as high as 50%, and the mortality rate of combined meningitis pituitary abscesses is 45%.12 Therefore, early diagnosis, timely surgery and reasonable antibiotic treatment are the keys to improve the prognosis of pituitary abscesses, and nasal endoscopy is widely used and worth promoting.