Review of Pineal Anlage Tumor With Divergent Histology

Embryonal and pineal tumours

Embryonal and pineal tumours represent a diverse group of central nervous system (CNS) neoplasms. While many of the small round blue cell tumours that make up the embryonal neoplasms share similar histologic qualities, there are several morphologic and cytologic characteristics that are useful in distinguishing different tumour types. Similarly, pineal parenchymal tumours represent clinically diverse tumours, ranging from benign to overtly malignant. The most recent iteration of the World Health Organization Classification of CNS Tumours expanded greatly on the significance of molecular alterations in brain tumour diagnostics. In this article, we summarize the salient cytologic and histologic features of CNS embryonal and pineal tumours, and highlight diagnostically relevant molecular alterations within each tumour type.

Pineal anlage tumor: clinical and diagnostic features, and rationales for treatment

PURPOSE

To provide a treatment-focused review and develop basic treatment guidelines for patients diagnosed with pineal anlage tumor (PAT).

METHODS

Prospectively collected data of three patients with pineal anlage tumor from Germany was combined with clinical details and treatment information from 17 published cases.

RESULTS

Overall, 20 cases of PAT were identified (3 not previously reported German cases, 17 cases from published reports). Age at diagnosis ranged from 0.3 to 35.0 (median: 3.2 ± 7.8) years. All but three cases were diagnosed before the age of three years. For three cases, metastatic disease at initial staging was described. All patients underwent tumor surgery (gross-total resection: 9, subtotal resection/biopsy: 9, extent of resection unknown: 2). 15/20 patients were alive at last follow-up. Median follow-up for 10/15 surviving patients with available follow-up and treatment data was 2.4 years (0.3-6.5). Relapse was reported for 3 patients within 0.8 years after diagnosis. Five patients died, 3 after relapse and 2 from early postoperative complications. Two-year-progression-free- and -overall survival were 65.2 ± 12.7% and 49.2 ± 18.2%, respectively. All 4 patients who received intensive chemotherapy including high-dose chemotherapy combined with radiotherapy (2 focal, 2 craniospinal [CSI]) had no recurrence. Focal radiotherapy- and CSI-free survival rates in 13 evaluable patients were 46.2% (6/13) and 61.5% (8/13), respectively.

CONCLUSION

PAT is an aggressive disease mostly affecting young children. Therefore, adjuvant therapy using intensive chemotherapy and considering radiotherapy appears to comprise an appropriate treatment strategy. Reporting further cases is crucial to evaluate distinct treatment strategies.

Histopathology and molecular pathology of pediatric pineal parenchymal tumors

Pineal parenchymal tumors in children are rare. They consist of two main types, pineoblastoma (PB) and pineal parenchymal tumor of intermediate differentiation (PPTID), which are World Health Organization (WHO) grade 4 and grade 2-3 respectively. PBs are divided into four distinct molecular groups: PB-miRNA1, PB-miRNA2, PB-RB1, and PB-MYC/FOXR2. PB-RB1 and PB-MYC/FOXR2 affect young children and are associated with a dismal prognosis. PB-miRNA1 and PB-miRNA2 groups affect older children and follow a more favorable course. They are characterized by mutually exclusive alterations in genes involved in miRNA biogenesis, including DICER1, DROSHA, and DGCR8. They may be sporadic or may represent one manifestation of DICER1 syndrome. PB-RB1 tumors show alterations in the RB1 gene and may develop in the setting of congenital retinoblastoma, a condition known as "trilateral retinoblastoma." In the pediatric population, PPTIDs typically affect adolescents. They are characterized by small in-frame insertions in the KBTBD4 gene which is involved in ubiquitination.

Pineal anlage tumor: a case report and the literature review

PURPOSE

Pineal anlage tumor is an extremely rare tumor which was considered as a subtype of pineovlatoma with an overall poor prognosis. This case-based review further summarize the clinical profile.

METHODS

A patient with pineal anlage tumor was reported, her clinical data and gene analysis results were recorded.

RESULTS

An 8-month-old girl, with an obvious enhancing pineal occupancy and obstructive hydrocephalus. Her histological and immunohistochemical findings contained rhabdomyoblastic, melanin pigment and cartilage island. The wholeexpme sequencing and genome-wide copy number variation sequencing were performed, no mutations associated with pineoblatoma as well as copy number variants were identified. In terms of treatment, our patient underwent subtotal resection without radiotherapy or chemotherapy, and the residual tumor enlarged 4 months after surgery. We have followed her up for 10 months, and the child is still alive.

CONCLUSION

Surgery combined radiotherapy and chemotherapy is still the best treatment currently,and genetic testing for patients is necessary.

Pineal anlage tumor: a case report and review of the literature

PURPOSE

Pineal anlage tumors (PAT) are extremely rare malignant tumors in the pediatric population considered to be a variant of pineoblastomas. These tumors are characterized by a combination of neuroectodermal and heterologous ectomesenchymal components. PAT can be clinically aggressive and has a propensity to cerebrospinal fluid (CSF) dissemination. So far, only 13 cases of these tumors have been reported in the literature.

CASE ARTICLE

In this article, we report the case of an anlage tumor in a 3-year-old girl with a rapidly aggressive course.

Two cases of pineal anlage tumor with molecular analysis

Pineal anlage tumor is a rare pediatric tumor with clinical and histological features overlapping with pineoblastoma. Two patients with pineal anlage tumor, a 13-month-old female and an 11-month-old male, underwent subtotal resection, high-dose chemotherapy with autologous stem cell rescue, and radiation. Neither had tumor progression 50 months after diagnosis. The tumors underwent next-generation sequencing on a panel of 340 genes. Chromosomal copy gains and losses were present and differed between the tumors. No mutations or amplifications, including none specific to pineoblastoma, were identified.

Pineal anlage tumor: A case report and clinico-pathological review

Pineal anlage tumor (PAT) is an extremely rare tumor of paediatric population. It is considered as a subtype of pineoblastoma having ectomesenchymal/ rhabdomyoblastic and cartilaginous differentiation. PAT is presumed to have an aggressive behaviour with propensity for craniospinal fluid (CSF) spread due to histologically resemblance with pineoblastoma, thus requiring intensive multimodality treatment with craniospinal irradiation and chemotherapy. Here we report a case of PAT in a 35 years old lady along with clinical and pathological review. To the best of our knowledge only less than ten cases of pineal anlage tumors have been reported in the literature and index case is only second in the adult age group (rare histology in rare age group).

An unusual variant of anlage tumor of pineal region in an infant

A 9-month-old male child was brought with complaints of increasing head size for 2 months, increasing lethargy and vomiting for the last 2 days. Radiology revealed a heterogeneously enhancing, globular lesion in the pineal region with hydrocephalus. Near total excision of the tumor was carried out. The histopathological examination of the lesion showed heterogenous elements in the form of mature neuroepithelial and ectomesenchymal tissue. The pathology and radiology of this unusual lesion is discussed with relevant review of literature.

Diffusion characteristics of pediatric pineal tumors

BACKGROUND

Diffusion weighted imaging (DWI) has been shown to be helpful in characterizing tumor cellularity, and predicting histology. Several works have evaluated this technique for pineal tumors; however studies to date have not focused on pediatric pineal tumors.

OBJECTIVE

We evaluated the diffusion characteristics of pediatric pineal tumors to confirm if patterns seen in studies using mixed pediatric and adult populations remain valid.

MATERIALS AND METHODS

This retrospective study was performed after Institutional Review Board approval. We retrospectively evaluated all patients 18 years of age and younger with pineal tumors from a single institution where preoperative diffusion weighted imaging as well as histologic characterization was available.

RESULTS

Twenty patients (13 male, 7 female) with pineal tumors were identified: seven with pineoblastoma, four with Primitive Neuroectodermal Tumor (PNET), two with other pineal tumors, and seven with germ cell tumors including two germinomas, three teratomas, and one mixed germinoma-teratoma. The mean apparent diffusion coefficient (ADC) values in pineoblastoma (544 ± 65 × 10⁻⁶ mm²/s) and pineoblastoma/PNET (595 ± 144 × 10⁻⁶ mm²/s) was lower than that of the germ cell tumors (1284 ± 334 × 10⁻⁶ mm²/s; p < 0.0001 vs pineoblastoma). One highly cellular germinoma had an ADC value of 694 × 10⁻⁶ mm²/s.

CONCLUSION

ADC values can aid in differentiation of pineoblastoma/PNET from germ cell tumors in a population of children with pineal masses.

Pineal anlage tumour - a rare entity with divergent histology

Pineal anlage tumour is a rare tumour of the pineal gland that is not listed in the 2007 World Health Organization classification of tumours of the central nervous system. Pineal anlage has been defined as a primary pineal tumour with both neuroepithelial and ectomesenchymal differentiation but without endodermal differentiation. We report a pineal anlage tumour in a 4-month-old boy, the youngest patient reported with this rare tumour, with a brief review of the literature. Clinicians and neuropathologists should be aware of this entity as it is likely to be misdiagnosed as a teratoma or a melanocytic tumour of the central nervous system.

Pineal anlage tumor in a 5-month-old boy

Pineal tumors are rare neoplasms that are categorized into pineoblastomas, pineocytomas, and pineal parenchymal tumors of intermediate differentiation. Pineal anlage tumors are primary pineal tumors with neuroepithelial and ectomesenchymal differentiation and without endodermal differentiation. The authors review the literature and report the case of a 5-month-old boy with a pineal anlage tumor. This is only the sixth case of a pineal anlage tumor reported in the English-language literature adding to the understanding of this tumor's presentation, immunomorphological and molecular characteristics, embryological origin, radiological appearance, treatment outcome, and prognosis.