Key-words:
Craniopharyngioma - neurocysticercosis - sellar - suprasellar
Introduction
Neurocysticercosis (NCC) is one of the most common central nervous systems helminthic
infections in the developing countries and a major cause of acquired seizure and epilepsy.[[1]],[[2]],[[3]] Although NCC is highly pleomorphic in its presentation,[[4]] it usually affects the highly vascular gray-white matter junction, basal cistern,
subarachnoid space, and ventricles.[[4]],[[5]],[[6]] However, the suprasellar region is an unusual location for cysticerci and their
symptoms and locations resemble with sellar space-occupying lesions.[[4]],[[7]] We describe herein a case of suprasellar NCC extending into the sellar region which
mimics as a craniopharyngioma.
Case Report
We report a 28-year-old male, presented with rapid progressive loss of vision of the
left eye and headache. Neurological examination of the patient revealed no abnormalities
except visual acuity of the left eye to be 6/30. Visual field test and visual perimetry
showed temporal hemianopia of the left eye.
Magnetic resonance imaging (MRI) of the brain revealed well-defined lobulated cystic
lesion measuring about 1.9 cm × 2 cm × 1.9 cm (Anterior-Posterior × Width × Height)
showing thin enhancing wall without internal enhancing lesion located in mid to left
side of the suprasellar region extending into the sellar region. [[Figure 1]]a,[[Figure 1]]b,[[Figure 1]]c There was minimal extensive involvement of the left cavernous sinus, right deviation
and compression of infundibulum, and slightly upward pushed optic chiasma. However,
on SWI sequence, there is no calcification. [[Figure 1]]d,[[Figure 1]]e With craniopharyngioma as one of the differential diagnosis, pituitary hormonal
profile of the patient showed increased level of serum prolactin and insulin-like
growth factor 1, decreased level of serum cortisol. Other hormones were within normal
range. The provisional diagnosis of craniopharyngioma was made and standard pterional
craniotomy was performed from the left side. After visualizing the left optic nerve
and opening the left optico-carotid cistern, to our surprise, whitish multiple cystic
structure was seen which was removed from optico-carotid space and prechiasmatic space.
[[Figure 2]] Borosilicate glass pipette was used for meticulous removal of cystic lesion. The
scolex was also seen in the cyst. Few calcifications were also present. Dexamethasone
diluted in ringer's lactate was used for irrigation. Postoperatively, visual acuity
improved without any complications. Visual acuity improved with no postoperative complications.
Histopathology report showed findings compatible with cysticercosis [[Figure 3]]. However, immunoglobulin G appeared to be negative after surgery. Postoperative
CT scan was unremarkable [[Figure 4]].{Figure 1}{Figure 2}{Figure 3}{Figure 4}
Figure 1: (a) Magnetic resonance imaging of the brain T2 coronal section showing well-defined
lobulated lesion, hyperintense signal changes in mid to left side of suprasellar region
with minimal extensive involvement of the left cavernous sinus. (b and c) Postcontrast
axial section and sagittal section, respectively, showing slight irregular lesion
wall with postcontrast enhancement with no obvious internal enhancing lesion or septa.
(d and e) SWI sequence revealed no calcification
Figure 2: Frontal lobe retraction showing cystic lesion in the suprasellar region
Figure 3: H and E stain showing outer cuticular layer, middle nuclear layer, and the inner
reticular layer of the cyst wall (magnification: ×40)
Figure 4: Postoperative Computed tomography scan showing complete removal of suprasellar lesion
Discussion
In developing countries such as Nepal, with poor personal hygiene, NCC is caused by
intake of contaminated food and water containing larval stage of Taenia solium.[[3]],[[5]],[[8]],[[9]] Seizure is the most common presentation of NCC.[[1]],[[2]]
Sellar/suprasellar location of NCC is very rare and is usually presented with a nonspecific
clinical presentation.[[4]],[[5]],[[10]] In this case, we present vision loss and endocrinological disturbances as the prime
symptoms which can be explained by the variety of pathologies, the most common being
direct invasion of the sellar region by cysts with compression of optic chiasma and
the pituitary stalk or the hypophysis itself or caused by opticochiasmatic arachnoiditis.[[4]],[[7]],[[11]] Computed tomography and MRI diagnose NCC in its different stages.[[1]],[[12]],[[13]] However, intrasellar/suprasellar NCC is difficult to be diagnosed by MRI due to
the absence of the scolex.[[10]]
NCC can be detected by serum and cerebrospinal fluid anticysticercosis antibodies,
cysticercal antigens, especially in the patient from cysticercus epidemic areas.[[10]] However, in sellar/suprasellar NCC these immunological marker are found to be negative.[[5]] Hence, for sellar/suprasellar NCC biopsy or necropsy specimens are needed for histopathological
confirmation.[[5]]
NCC can be treated conservatively and surgically. Conservative management includes
the use of albendazole and praziquantel which provides proven efficacy against parenchymal
NCC; however, there are no studies confirming their efficacy in sellar cysts.[[4]],[[5]] The use of corticosteroids[[7]] and hormone replacement has also been used to correct the endocrine abnormalities
and to decrease local inflammation and edema caused by surgical or medical treatment.[[14]]
In surgical approach, pterional craniotomy is considered to be best as it allows excision
of the whole cyst and relieves the optic chiasm and nerves from thick adhesions that
could pass unnoticed.[[5]],[[10]] Besides this, transsphenoidal and extended transsphenoidal surgical approaches
have been successfully used to achieve the fenestration or resection of the cyst.[[5]],[[15]] Prompt surgical resection of the sellar lesion is recommended to stop progression
of the disease and to avoid irreversible loss of visual function.[[4]],[[5]]
Biopsy of the NCC microscopically represents solices of cysticercus to be a dense
wavy cuticle with focal globular structures.[[16]] A surrounding inflammatory, mononuclear lymphocytic reaction with plasma cells
is often observed. A variable degree of eosinophilia may be seen.[[14]]
Conclusions
Sellar/suprasellar NCC is a very rare entity. Clinical findings, neuroimaging may
not be conclusive of NCC, especially when there are sole manifestations of sellar
involvement without the involvement of any other location. The most common clinical
presentation is headache, visual loss, hypopituitarism, meningitis, and seizure. MRI
findings are not conclusive of sellar NCC due to poor visibility of scolex. Only intraoperative
features of cyst and postoperative biopsy become conclusive of sellar NCC. NCC should
be considered as one of the differential diagnoses in sellar/suprasellar cysts in
our part of the world.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms.
In the form the patient(s) has/have given his/her/their consent for his/her/their
images and other clinical information to be reported in the journal. The patients
understand that their names and initials will not be published and due efforts will
be made to conceal their identity, but anonymity cannot be guaranteed.
