The World Health Organization Classification of Tumors of the Central Nervous System 2007 is as follows: – “A rare neuroepithelial tumor of the pineal region in adults, characterized by papillary architecture and epithelial cytology, immunopositivity for cytokeratin and ultrastructural features suggesting ependymal differentiation.“ 1).
First described by Jouvet et al., in 2003 who reported six cases and called it a “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 Jouvet et al.'s initial report 2).
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 3).
They arise from specialized ependymocytes in the subcommissural organ, which is located in the pineal region. Characterized by papillary architecture and epithelial cytology, immunopositivity for cytokeratin and ependymal differentiation. It is considered grade II-III by the World Health Organization.
A review of the literature was performed to collect all the cases published with gross total resection and no complementary treatment. In conclusion, there is still much to be learned about the pathogenesis, prognosis, and management of this tumor. 4).
Papillary tumor of pineal region (PTPR) arises exclusively in the pineal region and occurs most commonly in adults with slight preponderance in females.
Till 2008, about 64 cases of PTPR have been reported 5).
Rarely in children (19 cases reported up to now) 6).
Department of Neurosurgery and Gamma Knife Radiosurgery, San Raffaele Scientific Institute, Vita-Salute University, Milan, Italy. Papillary tumor of pineal region WHO II/III (4.7%) 7).
The clinical behavior is often aggressive. Headache of short duration is the common presenting symptom. This occurs due to increased intracranial tension as a result of compression of the aqueduct.
They may also have a cystic component. CT imaging shows their hypodense nature and enhancement with contrast. MRI demonstrates Hypointensity in T1-weighted (T1W) sequence and hyperintensity in T2-weighted (T2W) sequence and enhance with contrast 8).
Bora et al. retrospectively analyzed the outcome of 11 patients, with histopathologically proven PTPR, who underwent surgical excision at the All India Institute of Medical Sciences.
The mean age was 33.3 years (range:12-45 years) and the male: female ratio was 1.75:1. Headache was the most common presentation followed by visual disturbances, altered sensorium, Perinaud's syndrome and seizures. 6 patients required CSF diversion. Krause approach was the most common approach used for tumor excision (in 9 of 11 cases). There was no perioperative mortality. Two patients were lost to followup. In the rest 9 patients, the average follow-up period was 45 months (range: 12-79 months). On the first postoperative MRI, 8 patients showed no evidence of residual tumor (GTR) while one patient had a small residual tumor (NTR) that remained stable during follow-up. Four patients underwent adjuvant chemo-radiotherapy. None of the patients developed recurrence during follow-up.
PTPR is a rare subgroup of pineal region tumors with distinct cells of origin but presentation similar to other pineal region tumors. Surgical resection constitutes the mainstay of management and the extent of resection appears to be the most important determinant of prognosis. The role of adjuvant therapy, however, still needs to be determined 9).
Three female pediatric patients with PTPR were treated in King Fahad Medical City (KFMC) in Saudi Arabia. Histological and immunohistochemical diagnosis was confirmed by analysis of genome-wide DNA methylation profiles. This case series expands on the available reports on the clinical presentations of PTPR and provides important information on the responses to different treatment modalities 10)
Little is known about the prognostic markers that might aid to identify patients at increased risk for recurrence. Therefore, the prognostic value of histopathologic and clinical features was examined in a series of 21 patients. Median age of the 12 male and 9 female patients was 35 years (range, 10 to 56 y). On histopathologic examination, all tumors were characterized by loose papillary structures and tumor cells forming broad perivascular pseudorosettes showing cytokeratin expression. In addition, tumors showed increased cellularity (n=4; 19%), nuclear pleomorphism (n=4; 19%), solid growth (n=11; 52%), necrosis (n=8; 38%), increased mitotic activity (≥3 mitoses per 10 high-power fields [n=10; 48%]), and increased proliferation (Ki67/MIB1 index ≥10% [n=8/20; 40%]). Gross total resection could be achieved in 13/21 patients (62%). Postoperatively, 13 patients received radiotherapy and 4 patients chemotherapy. Median recurrence-free survival was 66 months in 19 patients, for whom detailed follow-up information was available. Twelve patients (63%) experienced tumor progression. Three patients (16%) died of disease. Among the clinical and histopathologic features examined, only increased mitotic activity (52 [8 to 96] vs. 68 [66 to 70] mo [median [95% confidence interval]]) and proliferative activity (29 [0 to 64] vs. 67 [44 to 90] mo) were significantly associated with recurrence (P<0.05). Tumors of the 3 patients who had succumbed to disease showed increased mitotic and proliferative activity.
Increased mitotic and proliferative activities are associated with worse prognosis in papillary tumors of the pineal region 11).