|Year : 2020 | Volume
| Issue : 2 | Page : 18-19
Microscopic perivascular pseudorosettes in a child with fourth ventricular tumor
Thirunavukkarasu Arun Babu1, Padmapriya Balakrishnan2
1 Department of Pediatrics, All India Institute of Medical Sciences (AIIMS), Mangalagiri, Andhra Pradesh, India
2 Resident in Pathology, Indira Gandhi Medical College and Research Institute (IGMC&RI), Puducherry, India
|Date of Submission||01-May-2021|
|Date of Acceptance||16-Oct-2021|
|Date of Web Publication||27-Apr-2022|
Thirunavukkarasu Arun Babu
Department of Pediatrics, All India Institute of Medical Sciences (AIIMS), Mangalagiri, Andhra Pradesh
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Arun Babu T, Balakrishnan P. Microscopic perivascular pseudorosettes in a child with fourth ventricular tumor. Int J Head Neck Pathol 2020;3:18-9
|How to cite this URL:|
Arun Babu T, Balakrishnan P. Microscopic perivascular pseudorosettes in a child with fourth ventricular tumor. Int J Head Neck Pathol [serial online] 2020 [cited 2022 May 25];3:18-9. Available from: https://www.ijhnp.org/text.asp?2020/3/2/18/344177
Histopathology plays an important role in confirming the specific diagnosis in many cases of suspected intracranial neoplasms. We are reporting an atypical presentation of posterior fossa tumor with seizures in a child in whom specific diagnosis was made by classic histopathology findings.
A 4-year-old female presented with episodes of jerky movements of upper and lower limbs with transient loss of consciousness and post-episodic paralysis of limbs for 1 week. Child was conscious, alert, active, and afebrile. Central nervous system and respiratory and cardiac system examination were normal. Fundus examination showed bilateral papilledema. Magnetic resonance imaging brain showed mixed intensity lesion of 3.5 × 3 cm arising from the floor of the fourth ventricle causing obstructive hydrocephalus. Hematological investigations were normal. Ventriculoperitoneal shunt for acute obstructive hydrocephalus was done to decrease raised intracranial pressure. Intraoperatively, tumor was soft, friable, irregular, and grey white arising from the floor of the fourth ventricle. Total resection of tumor was attempted. Histopathological examination showed that moderately cellular tumor is composed of monomorphic cells with fibrillary cytoplasm, round to oval nucleus with salt and pepper chromatin. There were numerous perivascular pseudorosettes and areas of calcification [Figure 1] and [Figure 2]. There were no mitotic figures and features of anaplasia. Diagnosis of classic ependymoma WHO grade II was made based on age of child, site of tumor, and histopathological features.
|Figure 1: Photomicrograph showing moderately cellular tumor composed of monomorphous cells arranged diffusely and as perivascular pseudorosettes (H&E stain, 400×)|
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|Figure 2: Photomicrograph showing perivascular pseudorosettes composed of nuclear-free cytoplasmic fibrillary zone of tumor cells around capillaries with monomorphic round to oval nuclear and salt and pepper chromatin (H&E stain, 400×)|
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Ependymoma, medulloblastoma, juvenile pilocytic astrocytoma, and brainstem glioma are important differential diagnoses for posterior fossa mass in children. Posterior fossa tumors usually present with vomiting, headache, cerebellar signs (if located in cerebellum), and hydrocephalus while seizures as presenting symptom is rare. Tumor cells resemble normal ependymal cells but are arranged in unique perivascular pseudorosettes. In pseudorosette formation, the tumor cell nuclei are located at a distance from a central vessel with delicate processes radiating toward the vessel wall.
In conclusion, we are presenting a child with posterior fossa ependymoma presenting with seizures, which was diagnosed by classic histopathology findings.
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Conflicts of interest
There are no conflicts of interest.
PB and TA conceived the concept, contributed to case management, reviewed the literature, and drafted the manuscript. Both authors have approved the final version of the manuscript. TA shall act as guarantor of the paper.
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Signed informed consent is obtained from the parent.
| References|| |
Iddrissu M, Dakurah T, Wepeba G. Anaplastic ependymoma of the fourth ventricle causing obstructive hydrocephalus. Ghana Med J 2005;39:33-6.
Prasad KSV, Ravi D, Pallikonda V, Raman BVS. Clinicopathological study of pediatric posterior fossa tumors. J Pediatr Neurosci 2017;12:245-50.
Malhotra A, Rao S, Santhoshkumar R, Muralidharan N, Mitra S, Shetty S. Pigmented ependymoma of the fourth ventricle—A curious entity: Report of a rare case with review of literature. Int J Surg Pathol 2020:1066896920926700.
[Figure 1], [Figure 2]