|Year : 2013 | Volume
| Issue : 3 | Page : 302-304
Papillary tumor of pineal region: A rare entity
Meena Patil, Manjiri Karandikar
Department of Pathology, Bharti Vidyapeeth University Medical College, Pune, India
|Date of Web Publication||5-Jul-2013|
Department of Pathology, Bharti Vidyapeeth University Medical College, Pune
Source of Support: None, Conflict of Interest: None
Pineal tumors comprise 0.4-1.0% of intracranial space occupying lesions in adults. Papillary tumor of pineal region (PTPR) is a very rare entity. It has been newly described in WHO 2007 classification of brain tumors. Only a few case reports are available in the literature. We report a case of a 60-year-old female presenting with headache, giddiness and reduced vision. Imaging studies showed a pineal mass with areas of hemorrhage. All ventricles were normal. There was a past history of a pineal gland tumor excised 2 years ago. This case is being reported for its rarity and aggressiveness in the form of recurrence. Limited/available immunohistochemistry workup has been done.
Keywords: Intracranial space occupying lesions, papillary tumor of pineal region, pineal region tumors, WHO classification of brain tumors
|How to cite this article:|
Patil M, Karandikar M. Papillary tumor of pineal region: A rare entity. Med J DY Patil Univ 2013;6:302-4
| Introduction|| |
Papillary tumor of pineal region (PTPR) arises exclusively in the pineal region and occurs most commonly in adults with slight preponderance in females. Headache of short duration is the common presenting symptom. This occurs due to increased intracranial tension as a result of compression of the aqueduct. Various other names, like papillary pineocytoma, pineal parenchymal tumor, choroid plexus tumor, ependymoma and papillary meningioma have been given to these tumors in earlier reports. ,,
| Case Report|| |
A 60-year-old female presented with headache, giddiness and reduced vision in both eyes for 2 months. There was a past history of a pineal gland tumor compressing third ventricle and presenting with hydrocephalus, excised 2 years back. Histopathology of the previous resection for pineal gland tumor was not available, but patient had not taken any adjuvant therapy after surgery. MRI brain showed a pineal mass 4 × 3.3 cm, with hemorrhage, hyperintensity on precontrast T1- weighted image. Ventricles were normal and there was a shunt in situ.
Histopathology revealed a cellular neoplasm characterized by eosinophilic cells with indistinct cell borders, with columnar and cuboidal morphology [Figure 1]. They were arranged in perivascular pseudorosettes and in a distinctive papillary growth pattern. Blood vessels appeared to be covered by multiple layers of tumor cells with pleomorphic nuclei.
Immunohistochemistry study showed strong reactivity for vimentin, S- 100 protein, focal positivity for p53, and low MIB 1 index [Figure 2] and [Figure 3]. EMA, CK 8-18, and GFAP, synaptophysin were negative.
A thorough retrospective search for any primary tumor outside the CNS was done and no tumor was found anywhere. In view of the past history of pineal gland tumor excision, a final diagnosis of papillary tumor of pineal region-grade II was offered. Incomplete resection may be the cause of recurrence in our case as the mitotic index was less than one mitotic figure per 10 high power field. The case is being followed up for the last 2 years and does not have any symptoms related to the tumor.
| Discussion|| |
Papillary tumor of pineal region is a rare entity, newly described in WHO 2007 classification of brain tumors and assigned a provisional code (ICD-O code of 9395/3).  In 2003, Jouvet and colleagues reported 6 cases and called it "papillary tumor of pineal region". The tumor's clinicopathological characteristics as described and illustrated in that series were very similar to the description of some entities reported by neuropathologists from different parts of the world. Many more independent case reports were published after Jovet's initial report.  Till now, about 64 cases of PTPR have been reported. 
The WHO 2007 definition of PTPR is as follows: "A rare neuroepithelial tumor of the pineal region in adults, characterized by papillary architecture and epithelial cytology, immunopositivity for cytokeratin and ultra structural features suggesting ependymal differentiation." 
They are well circumscribed and the size may vary from 2.5 to 4 cm. The age ranges from 5 years to 66 years while the mean age is 31.5 years.  They may also have a cystic component. CT imaging shows their hypodense nature and enhancement with contrast. MRI demonstrates hypointense in T1-weighted (T1W) sequence and hyperintense in T2-weighted (T2W) sequence and enhance with contrast. 
Symptoms are typically related to obstructive hydrocephalus secondary to compression of cerebral aqueduct. Progression occurs in almost 75% of patients. Incomplete resection and increased mitotic activity are negative prognostic factors. 
Although, the cell of origin is not definitely known, it is thought to be arising from the specialized ependymal cells of the subcomissural organ. The subcomissural organ which is present in animals, is present in the humans only during embryonic life and loses its function in adult life. 
A lot of effort has been done to decide the IHC profile of the tumor. The immunophenotype of PTPR has been extensively investigated. It shows immunoreactivity for a broad spectrum of cytokeratins, e.g., KL1, AE1/AE3, CAM5.2. Papillary areas are more consistently and strongly positive for CK18 than the solid areas.  However, some authors have reported negativity for CK, EMA, Synaptophysin and GFAP.  PTPRs have also been reported to express vimentin, S-100 protein, NSE, MAP2, N-CAM and transthyretin. Reactivity for GFAP has been reported in approximately 12% of tumors, typically restricted to focal perivascular areas of the tumor. Surface EMA expression is seen in most cases. No immunolabeling for neurofilament proteins has been reported.  In few cases NSE and synaptophysin was reported positive.  All pineal region lesions known to exhibit papillary architecture come in the differential diagnosis of papillary tumor of pineal region. These include pineal parenchymal tumors, papillary ependymoma, choroid plexus tumors, papillary meningioma, and metastases. Strong immunoexpression of neuronal markers help in differentiating papillary tumor of pineal region from pineal parenchymal tumors. Very low or absent expression of CK7/CK20 and low MIB-1 labeling indices are characteristic of PTPR. and differentiates it from metastatic papillary carcinomas of unknown primary. Both PTPR and choroid plexus papilloma express cytokeratins and transthyretin; however most PTPRs show MAP-2 staining and do not express Kir7.1, which is a marker of choroid plexus tumours. General lack of cytokeratin expression. Differentiate papillary meningioma from papillary tumour of pineal region. Papillary tumours of pineal region are characterized by frequent local recurrence but only occasional spinal dissemination. Therefore, the WHO panel put them in grades II or III category. 
| References|| |
|1.||Roncaroli F, Scheiehaver BW. Papillary tumor of pineal region; New tumor entity in the 2007 WHO classification. Brain Pathol 2007;17:314-8. |
|2.||Kleihues P, Cavenee WK, editors. World Health Organization Classification Of Tumours. Pathology and Genetics of Tumours of Nervous System, No. 21. Geneva: World health Organization; 1979. Lyon: IARC Press, 1979. |
|3.||Fuller GN. The increasing diversity of Pineal and Sellar region tumors, American Association Of Neuropathologists USCAP Companion Society Inaugral Meeting Denver, CO 2008. |
|4.||Jouvet A, Fauchon F, Liberski P, Saint-Pierre G, Didier-Bazes M, Heitzmann A, et al. Papillary Tumour of the Pineal Region. Am J Surg Pathol 2003;27:505-2. |
|5.||Epari S, Bashyal R, Malick S, Gupta T, Moyadi A, Kane SV, et al. Case report: Papillary tumour of pineal region: Report of three cases and review of literature, Neurol India 2011;59:455-60. |
|6.||Kim YH, Kim JW, Park CK, Kim DG, Sohn CH, Chang KH, et al. Papillary tumour of pineal region presenting with leptomeningeal seeding. Neuropathology 2010;30:654-60. |
|7.||Sharma MC, Jain D, Sarkar C, Suri V, Garg A, Sharma BS, et al. Papillary tumour of the pineal region-a recently described entity: A report of three cases and review of the literature. Clin Neuropathology 2009;28:295-302. |
[Figure 1], [Figure 2], [Figure 3]