User:Chelsea Proffitt

Papillary Tumors of the Pineal Region are located on the pineal gland. The pineal gland is located on roof of the diencephalon. It is a cone shaped structure dorsal to the midbrain tectum. ** Oncology ** The tumor appears to be derived from the specialized ependymal cells of the subcommissural organ. ** Tumor in Child & Kern & Raul** Papillary tumors of the central nervous system and particularly of the pineal region are very rare and so diagnosing them is extremely difficult. ** MR Imaging **

Characterestics of Pineal Region Tumors
Pineal region tumors are normally composed of variety of cells including astrocytes, ganglion cells, blood vessels, and pinocytes, which are the cells of this organ. Pineocytes are specialized neurons, which are rich in monoaminergic neurotransmitters, including, serotonin, norepinephrine, and melatonin. ** Oncology ** Specifically, papillary tumors of this region are made up of ependymal cells which form papilla. The papilla is meant to be surface cells. The ependymal cells line the inside of the ventricles of the brain. These cells have proteins that make up the characteristics of the tumor. These proteins arise from blood vessels, nerve cells and muscle cells. **interview**

These tumors, papillary tumors in this case, have no known predisposing genetic characteristics. There is nothing that links the likelihood of getting this tumor type to genetics, meaning nothing is inherited. However, technically speaking, there is genetics involved, just not in the sense of inheritability. The tumor cells may differ in their structure and function, but they all have normal function, which is directed by the deoxyribonucleic acid, or DNA. There are meant to be certain cells in a specific area, for the pineal region these are ependymal cells, and the cells divide into millions. As these cells divide, their genetic material is being copied. In a tumor, there is a collection of mutations that are typos in the genetic material, which disrupts the function of the normal cell. Therefore, the cells differentiate from what they were meant to be. If the abnormal cells continue to grow, divide, and produce more abnormal cells, the mass of abnormal cells may eventually become a tumor. ** 100 & interview**

Papillary tumors of the pineal region are normally well circumscribed. They are reported to be fairly large ranging between 2.5 to 4.0 centimeters. These tumors sometimes feature a cystic component. **WHOO***

Incidence
As stated before, papillary tumors of pineal region are extremely rare. They constitute 0.4-1% of all central nervous system tumors. ** Oncology**

These tumors most commonly occur in adults with the mean age being 31.5. There have been cases reported for people between the ages 5 to 66 years. There is a slight predominance of females who have these tumors. ** WHO & Poulgrain

Grading of Tumor
Papillary tumor of the pineal region (PTPR) is a recently described neoplasm that has been formally recognized in the 2007 World Health Organization (WHO) “Classification of Tumors of the Nervous System.”  ** MR Imaging ** Because these tumors are so rare, at first there was really no way to grade these tumors. Once they were biopsied, they were defined as either malignant, meaning cancerous, or benign, meaning cancer free. After seeing more and more cases of this tumor, they are now determined to be either Grade II or Grade III, according to the WHO classification. **Oncology** The grade of tumors is determined by the amount of cell division that is taking place. The formula for determining the tumor grade is: # of cells dividing/ high power field   =    proliferation      **Interview** The mitotic activity varies for these tumors, ranging from 0 to 10 mitoses per 10 high power (x40) fields. **WHO**

Grade II
** A Primer of Brain Tumors **

Grade II tumors are relatively slow growing. They have a slightly abnormal microscopic appearance and can spread into nearby normal tissue. Grade II tumors can also recur as a higher-grade tumor.

Grade III
*** A Primer of Brain Tumors **

Grade III tumors are malignant. In these types of tumors the cells are actively reproducing abnormal cells. The cells of the tumor will often grow into nearby normal brain tissue. Grade III tumors tend to recur as higher-grade tumors.

Symptoms
The most common symptom of the papillary tumor is a headache. ** Chang&Kern&Sato** Because headaches are so common, most people think nothing of it. This is why brain tumors are so dangerous. There are not a lot of symptoms that go along with them so people tend to wait a long time before seeking medical help. Most of the time people will go see a doctor when their headaches become consistent and start to never go away. This symptom however occurs secondary to hydrocephalus, which is a result from compression of the cerebral aqueduct. The cerebral aqueduct is a narrow channel in the midbrain, which connects the third and fourth ventricles. When a tumor blocks the pathway of the cerebrospinal fluid, this will cause headaches in the patient. ** Boco ** Often times when hydrocephalus occurs, a shunt is put in place in order to alleviate the pressure. **Poulgrain.

In some cases, patients have had progressive diplopia, or double vision. ** Boco & Raul** Also, although not in all cases, patients sometimes suffer from nausea and vomiting. ** Kern & Poulgrain**

Histological and Immunohistochemical features
The critical diagnosis of this neoplasm is often difficult because of its similarity with other primary or secondary papillary lesions of the pineal region, including parenchymal pineal tumours, papillary ependymoma, papillary meningioma, choroid plexus papilloma and metastatic papillary carcinoma. ** Brain Pathology** Papillary tumors characteristically show a discrete, compressive border with adjacent pineal gland and brain parenchyma. The nuclei tend to be regular, round – to – oval and contain stippled chromatin. The cytoplasmic and often nuclear expression of S100 protein is present in nearly all tumor cells, and vimentin typically stains tumor cell cytoplasm adjacent to vessel walls. ** WHO ** The cells of this tumor usually show a columnar to cuboidal cytoplasm with a well-defined cytoplasmic membrane. Vacuolated, or clear cells are common. **Oncology**Necrosis or cell death is normally observed to some extent in most of these tumors cells. **WHO & Buffenoir** These tumors were tested immunohistochemically with a profile similar to that of a choroid plexus tumor; however, morphologically the tumors appeared to be less differentiated than a choroid plexus papilloma and more differentiated than a choroid plexus carcinoma ** Knife radiosurgery ** There is normally cytoplasmic staining for a number of cytokeratin’s and the immunohistochemical profile for the papillary tumors are as follows:

Cam5.2 (low molecular weight cytokeratin)		 +++ AE1/AE3 (pan-cytokeratin)				            - CK8/18 (cytokeratin 8/18)				         +++

EMA (epithelial membrane antigen)				    -

GFAP (glial fibrillary acidic protein)				    +

Synaptophysin	 						            -

Chromogranin							            -

NSE (neuron-specific enolase)				          ++

NFP (neurofilament protein)					    -

CD56/N-CAM (neural cell adhesion molecule)		  ++

S100								                  ++

Transthyretin							            -

Vimentin							                 +++

Desmin							                    -

SMA (smooth muscle actin) 					    +

The intensity of immunoreactivity was scored as follows: - (absent), + (weak/focal), ++ (moderate), and +++ (strong). ***Poulgrain