AJR 2000; 175:1570-1572
© American Roentgen Ray Society
Pituitary Aspergillosis Mimicking Pituitary Tumor
Jae-Hee Lee1,
Young Sup Park2,
Kyoung Mee Kim3,
Ki Jun Kim1,
Chang Ho Ahn2,
Sung Yong Lee1 and
Kyu H. Choi4
1
Department of Diagnostic Radiology, Our Lady of Mercy Hospital, College of
Medicine, The Catholic University of Korea, 665 Pupyungdong, Pupyonggu,
Incheon, 403-016 Korea.
2
Department of Neurosurgery, Our Lady of Mercy Hospital, College of Medicine,
The Catholic University of Korea, Incheon, 403-016 Korea.
3
Department of Pathology, Our Lady of Mercy Hospital, College of Medicine, The
Catholic University of Korea, Incheon, 403-016 Korea.
4
Department of Radiology, Kangnam St. Mary's Hospital, College of Medicine, The
Catholic University of Korea, Seoul, 137-040 Korea.
Received January 31, 2000;
accepted after revision May 16, 2000.
Address correspondence to J. H. Lee.
Introduction
Aspergillus species are common fungi that can be isolated from
various sources including soil, building materials, leaves, and food. The
fungal spores are commonly airborne and are inhaled by the host, accounting
for the predilection of Aspergillus infections for the respiratory
system [1]. Although
aspergillosis of the paranasal sinuses is a well-recognized form of fungal
infection, involvement of the pituitary gland by aspergillosis is extremely
rare and can be misdiagnosed as a pituitary tumor.
To our knowledge, only six cases of pituitary aspergillosis have been
reported in the literature, and most are associated with sphenoidal sinusitis
[1,2,3,4].
We describe a case of invasive aspergillosis that manifested as a pituitary
mass and osteomyelitis of the clivus and upper cervical spine in a young
immunocompetent patient without evidence of sphenoidal sinusitis.
Case Report
A 37-year-old woman who had no history of severe illness or trauma was
admitted to the hospital because of amenorrhea and blurred vision for the last
year. She took medication for amenorrhea. Findings at physical examination
were normal except for restricted lateral gaze of the right orbital globe.
Blood count and biochemical profile were normal. Most of the findings from the
basal hormonal studies were within the normal limits except for a slight
elevation of the serum prolactin level. She was neither HIV seropositive nor
had any reason to be immunocompromised. CD3, CD19, CD4, and CD8 levels were
within normal limits. Coronal CT of the sella with contrast enhancement showed
an enhancing pituitary mass and clear sphenoidal sinuses
(Fig. 1A). Because CT images
were obtained at an outside hospital and bone window images were not
available, bone destruction could not be confirmed. MR imaging showed a sellar
mass with suprasellar extension, which was isointense to gray matter on T1-
and T2-weighted images (Figs.
1B and
1C) and homogeneously enhanced
on contrast-enhanced T1-weighted images
(Fig. 1D). Upper clivus,
craniocervical junction, C1, and C2 were also involved with the same signal
intensity and contrast enhancement as the mass (Figs.
1B and
1D). Via a transsphenoidal
approach, irregular rubbery tan-gray fragments were removed from the pituitary
mass. Histologic examination of the excised pituitary gland showed marked
acute and chronic inflammatory cell infiltration with focal wellformed
granulomas. The central portion of granulomas contained necrotic cellular
debris with some neutrophils. After periodic acid—Schiff and methenamine
silver staining, bundles of hyphae were found in the necrotic areas,
consistent with aspergillosis (Fig.
1E). Amphotericin-B therapy was initiated on the fifth
postoperative day.
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Fig. 1A. —37-year-old woman with invasive aspergillosis manifested as
pituitary mass and osteomyelitis of skull base. Contrast-enhanced coronal CT
scan at level of third ventricle shows enhancing sellar and suprasellar mass.
Note clear sphenoidal sinus.
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Fig. 1B. —37-year-old woman with invasive aspergillosis manifested as
pituitary mass and osteomyelitis of skull base. Mid sagittal T1-weighted MR
image shows sellar and suprasellar mass (solid arrow) that is
isointense to gray matter. Mass appears to extend posteriorly along
infundibulum, which is unusual for pituitary adenoma. Note low signal change
in bone marrow of clivus, craniocervical junction, and odontoid process of C2
(open arrows).
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Fig. 1C. —37-year-old woman with invasive aspergillosis manifested as
pituitary mass and osteomyelitis of skull base. Mid sagittal T2-weighted MR
image shows pituitary mass with suprasellar extension (solid arrows)
that has iso- to low signal intensity to gray matter. Lesions in clivus,
craniocervical soft tissue, and upper cervical region also show low signal
intensity (open arrows).
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Fig. 1D. —37-year-old woman with invasive aspergillosis manifested as
pituitary mass and osteomyelitis of skull base. Mid sagittal contrast-enhanced
T1-weighted MR image shows strong enhancement of pituitary mass with
suprasellar extension (solid arrow) and lesions in clivus,
cervicocranial junction, and parts of C1 and C2 (open arrows).
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Fig. 1E. —37-year-old woman with invasive aspergillosis manifested as
pituitary mass and osteomyelitis of skull base. Photomicrograph obtained from
histologic examination of necrotic areas shows bundles of hyphae, which are
branched at acute angles. (Methenamine silver stain, x400)
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Discussion
Although Aspergillus infections of paranasal sinuses are well
recognized, involvement of the pituitary gland is exceedingly rare. To our
knowledge, only six cases of pituitary aspergillosis have been reported
[1,2,3,4].
Unfortunately, none of these cases was preoperatively diagnosed. Four of the
six cases were related to sphenoidal sinusitis. The communication from the
sphenoidal sinus to the sella turcica through the vascular channels may be the
possible route of spread [1,
2]. Ramos-Garbatin and Jordan
[2] reported a case of primary
pituitary aspergillosis that was intraoperatively diagnosed without evidence
of sinus infection. Like their patient, our patient showed no evidence of
sphenoidal sinusitis. Instead of having sphenoidal sinusitis, our patient had
osteomyelitis involving the skull base. Vertebral osteomyelitis is also an
uncommon manifestation of aspergillosis, which can spread from respiratory
infection and can occur after surgery. The most common site for
Aspergillus osteomyelitis is the lumbar spine, followed by the
thoracic spine [5,
6]. Although our patient had no
evidence of sinusitis, it is presumed that Aspergillus spores
previously inhaled in the sphenoidal sinus might transverse the bone along the
vascular channels causing osteomyelitis of the skull base and pituitary
aspergillosis.
A low-signal-intensity pituitary mass on T2-weighted images and
accompanying low signal intensity in the adjacent bone marrow and soft tissues
on T2-weighted images in our patient were features of fungal infection that
differentiated it from pituitary adenoma or other sellar pathology.
Hypointensity on T2-weighted MR images is a well-known finding of fungal sinus
disease [7,
8]. It would be unusual for
other midline tumors such as chordoma or chondrosarcoma to appear as a
pituitary mass like this case.
In summary, our case is thought to be unique because invasive aspergillosis
involved the pituitary gland, skull base, and upper cervical region in a young
immunocompetent woman without sphenoidal sinusitis. If one is faced with a
pituitary adenoma with unusual features, such as hypointensity on T2-weighted
images, contiguous osteomyelitis, or sinusitis, then consider an infectious
process in the differential list of diagnoses.
References
-
Fuchs HA, Evans RM, Gregg CR. Invasive aspergillosis of the
sphenoid sinus manifested as a pituitary tumor. South Med
J 1985;78:1365
-1367[Medline]
-
Ramos-Gabatin A, Jordan RM. Primary pituitary aspergillosis
responding to transsphenoidal surgery and combined therapy with amphotericin-B
and 5-fluorocytosine. J Neurosurg
1981;54:839
-841[Medline]
-
Larranaga J, Fandino J, Gomez-Bueno J, Rodriguez D,
Gonzalez-Carrero J, Botana C. Aspergillosis of the sphenoid sinus simulating a
pituitary tumor. Neuroradiology
1989;31:362
-363[Medline]
-
Parker KM, Nicholson JK, Cezayirli RC, Biggs PJ. Aspergillosis of
the sphenoid sinus: presentation as a pituitary mass and postoperative
gallium-67 imaging. Surg Neurol
1996;45:354
-358[Medline]
-
Schubert M, Schar G, Curt A, Dietz V. Aspergillus spondylodiscitis
in an immunocompetent paraplegic patient. Spinal Cord
1998;36:800
-803[Medline]
-
Lang EW, Pitts LH. Intervertebral disc space infection caused by
Aspergillus fumigatus. Eur Spine J
1996;5:207
-209[Medline]
-
Zinreich SJ, Kennedy DW, Malat J, et al. Fungal sinusitis:
diagnosis with CT and MR imaging. Radiology
1988;169:439
-444[Abstract/Free Full Text]
-
Ashdown BC, Tien RD, Felsberg GJ. Aspergillosis of the brain and
paranasal sinuses in immuno-compromised patients: CT and MR imaging findings.
AJR
1994;162:155
-159[Abstract/Free Full Text]
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Introduction
Case Report
