AT/RT may be related to malignant rhabdoid tumor (MRT), which occurs outside the CNS, usually in the kidney. The finding that AT/RT and MRT both have deletions of the "INI1" gene indicates that rhabdoid tumors of the kidney and brain are at least closely related. AT/RT and MRT also have similar histology and similar clinical and demographic features. Moreover, 10–15% of MRT patients have simultaneous or subsequent brain tumors, many of which are secondary or primary MRT.

Clinical signs and symptoms depend on the location of the tumor.

Since many of the tumors occur in the posterior fossa, they present like other posterior fossa tumors, often with headache, vomiting, lethargy, and ataxia (unsteady gait). A case of a seven-month-old child with a primarily spinal tumor that presented with progressive paraplegia and abnormal feeling in the legs was reported.

Typical signs and symptoms of Wilms tumor include the following:

- a painless, palpable abdominal mass

- loss of appetite

- abdominal pain

- fever

- nausea and vomiting

- blood in the urine (in about 20% of cases)

- high blood pressure in some cases (especially if synchronous or metachronous bilateral kidney involvement)

Its presence is associated with either pilocytic astrocytoma (more common) or Alexander's disease (a rare leukodystrophy). They are also seen in the context of fucosidosis.

Pilocytic astrocytoma is the most common primitive tumor in pediatric patients.

A Rosenthal fiber is a thick, elongated, worm-like or "corkscrew" eosinophilic (pink) bundle that is found on H&E staining of the brain in the presence of long-standing gliosis, occasional tumors, and some metabolic disorders.

It is classified into two types, based on location in the body: peripheral PNET and CNS PNET.

There is a wide range of symptoms that patients show. Symptoms can lie dormant, but come about due to Obstructive hydrocephalus. These symptoms include:

- Intracranial pressure

- Headache

- Papilledema

- Vomiting

- Light headedness

- Impaired mental activity

- Gait instability

In rare and extreme cases, more severe symptoms can be observed:

- Memory disturbance

- Dementia

- Hemiparesis

- Seizures

- Hemorrhage

- Psychosis

Patients usually present with pain and limited range of motion caused by tumor's proximity to the joint space. Swelling may occur, as well, if the tumor has been growing for a long time. Some patients may be asymptomatic until they develop a pathologic fracture at the site of the tumor. They usually originate from the epiphysis of long bones, but in rare cases, they may arise from anterior arc of the ribs.

The symptoms may include muscular aches and pains in arms or legs and abdominal pain. Patients may also experience nerve pain which feels like an electric shock due to weight bearing.

There are three diagnostic criteria proposed:

1. the tumor arises along a peripheral nerve, or in a ganglioneuroma, or in a patient with neurofibromatosis type 1 (NF1), or has a metastatic character

2. the growth characteristics of the tumor is typical for a Schwann cell tumor

3. rhabdomyoblasts arise within the body of the tumor.

Primitive neuroectodermal tumor (PNET) is a malignant (cancerous) neural crest tumor. It is a rare tumor, usually occurring in children and young adults under 25 years of age. The overall 5 year survival rate is about 53%.

It gets its name because the majority of the cells in the tumor are derived from neuroectoderm, but have not developed and differentiated in the way a normal neuron would, and so the cells appear "primitive".

PNET belongs to the Ewing family of tumors.

Malignant triton tumor (MTT) is a relatively rare, aggressive tumor made up of both malignant schwannoma cells and malignant rhabdomyoblasts. It's classified as a malignant peripheral nerve sheath tumor with rhabdomyosarcomatous differentiation.

The unusual name "triton" was first used in reference to observation of supernumerary limbs containing bone and muscle growing on the backs of triton salamanders after the implantation of sciatic nerve tissue.

Individuals with this type of tumor may have no symptoms if cerebrospinal fluid (CSF) flow remains open. Obstruction of CSF flow will result in the symptoms associated with increased CSF pressure: nausea, vomiting, headache (often positional), lethargy, blurry or double vision, new or worsened seizures, and personality change.

The histology of EST is variable, but usually includes malignant endodermal cells. These cells secrete alpha-fetoprotein (AFP), which can be detected in tumor tissue, serum, cerebrospinal fluid, urine and, in the rare case of fetal EST, in amniotic fluid. When there is incongruence between biopsy and AFP test results for EST, the result indicating presence of EST dictates treatment. This is because EST often occurs as small "malignant foci" within a larger tumor, usually teratoma, and biopsy is a sampling method; biopsy of the tumor may reveal only teratoma, whereas elevated AFP reveals that EST is also present. GATA-4, a transcription factor, also may be useful in the diagnosis of EST.

Diagnosis of EST in pregnant women and in infants is complicated by the extremely high levels of AFP in those two groups. Tumor surveillance by monitoring AFP requires accurate correction for gestational age in pregnant women, and age in infants. In pregnant women, this can be achieved simply by testing maternal serum AFP rather than tumor marker AFP. In infants, the tumor marker test is used, but must be interpreted using a reference table or graph of normal AFP in infants.

Giant-cell tumor of the bone (GCTOB) is a relatively uncommon tumor of the bone. It is characterized by the presence of multinucleated giant cells (osteoclast-like cells). Malignancy in giant-cell tumor is uncommon and occurs in about 2% of all cases. However, if malignant degeneration does occur, it is likely to metastasize to the lungs. Giant-cell tumors are normally benign, with unpredictable behavior. It is a heterogeneous tumor composed of three different cell populations. The giant-cell tumour stromal cells (GCTSC) constitute the neoplastic cells, which are from an osteoblastic origin and are classified based on expression of osteoblast cell markers such as alkaline phosphatase and osteocalcin. In contrast, the mononuclear histiocytic cells (MNHC) and multinucleated giant cell (MNGC) fractions are secondarily recruited and comprise the non-neoplastic cell population. They are derived from an osteoclast-monocyte lineage determined primarily by expression of "CD68", a marker for monocytic precursor cells. In most patients, the tumors are slow to develop, but may recur locally in as many as 50% of cases.

Endodermal sinus tumor (EST), also known as yolk sac tumor (YST), is a member of the germ cell tumor group of cancers. It is the most common testicular tumor in children under 3, and is also known as infantile embryonal carcinoma. This age group has a very good prognosis. In contrast to the pure form typical of infants, adult endodermal sinus tumors are often found in combination with other kinds of germ cell tumor, particularly teratoma and embryonal carcinoma. While pure teratoma is usually benign, endodermal sinus tumor is malignant.

Wilms tumor, also known as nephroblastoma, is a cancer of the kidneys that typically occurs in children, rarely in adults. It is named after Dr. Max Wilms, the German surgeon (1867–1918) who first described it.

Approximately 500 cases are diagnosed in the U.S. annually. The majority (75%) occur in otherwise normal children; a minority (25%) are associated with other developmental abnormalities. It is highly responsive to treatment, with about 90% of patients surviving at least five years.

A ganglioneuroma is typically asymptomatic, and is typically only discovered when being examined or treated for another condition. Any symptoms will depend upon the tumor's location and the nearby organs affected.

For example, a tumor in the chest area may cause breathing difficulty, chest pain, and trachea compression. If the tumor is located lower in the abdomen, it may cause abdominal pain and bloating. A tumor near the spinal cord may cause spinal deformity or spinal compression, leading to pain and loss of muscle control or sensation in the legs and/or arms.

These tumors may produce certain hormones, which can cause diarrhea, an enlarged clitoris (in females), high blood pressure, increased body hair, and sweating.

Central neurocytoma, abbreviated CNC, is an extremely rare, ordinarily benign intraventricular brain tumour that typically forms from the neuronal cells of the septum pellucidum. The majority of central neurocytomas grow inwards into the ventricular system forming interventricular neurocytomas. This leads to two primary symptoms of CNCs, blurred vision and increased intracranial pressure. Treatment for a central neurocytoma typically involves surgical removal, with an approximate 1 in 5 chance of recurrence. Central neurocytomas are classified as a grade II tumor under the World Health Organization's classification of tumors of the nervous system.

Subependymal giant cell astrocytoma (SEGA, SGCA, or SGCT) is a low-grade astrocytic brain tumor (astrocytoma) that arises within the ventricles of the brain. It is most commonly associated with tuberous sclerosis complex (TSC). Although it is a low-grade tumor, its location can potentially obstruct the ventricles and lead to hydrocephalus.

Symptoms may include:

- Swelling in the extremities (arms or legs), also called peripheral edema; the swelling often is painless.

- Difficulty in moving the extremity that has the tumor, including a limp.

- Soreness localized to the area of the tumor or in the extremity.

- Neurological symptoms.

- Pain or discomfort: numbness, burning, or "pins and needles."

- Dizzyness and/or loss of balance.

Hemangioendotheliomas may be classified as:

- "Epithelioid sarcoma-like hemangioendothelioma" is an exceedingly rare vascular tumor of intermediate grade that was first described by Steven Billings, Andrew Folpe, and Sharon Weiss in 2003. These tumors are so named because their histologic appearance is very similar to that of epithelioid sarcoma, a more malignant tumor with which they are commonly mistaken.

- "Composite hemangioendothelioma" is a low-grade angiosarcoma typically occurring in adults, although it has been described in infancy.

- "Spindle-cell hemangioendothelioma") is a vascular tumor that was first described in 1986 by Sharon Weiss, M.D., and commonly presents in a child or young adult who develops blue nodules of firm consistency on a distal extremity. These tumors were reclassified by Dr. Weiss in 1996 as "spindle cell hemangioma", rather than hemangioendothelioma, due to the excellent prognosis observed in a group of 78 patients.

- "Retiform hemangioendothelioma" (also known as a "Hobnail hemangioendothelioma") is a low-grade angiosarcoma, first described in 1994, presenting as a slow-growing exophytic mass, dermal plaque, or subcutaneous nodule.

- "Kaposiform hemangioendothelioma" (also known as "Infantile kaposiform hemangioendothelioma") is an uncommon vascular tumor, first described by Niedt, Greco, et al. (Hemangioma with Kaposi's sarcoma-like features: report of two cases.(Niedt GW, Greco MA, Wieczorek R, Blanc WA, Knowles DM 2nd. that affects infants and young children, with rare cases having also been reported in adults.Pediatr Pathol. 1989;9(5):567-75.)

- "Endovascular papillary angioendothelioma", also known as "Dabska tumor", "papillary intralymphatic angioendothelioma" (PILA), "Dabska-type hemangioendothelioma", "hobnail hemangioendothelioma", and "malignant endovascular papillary angioendothelioma", is a rare low-grade angiosarcoma of lymphatic channels. Approximately 30 such tumors have been described in the medical literature. Although included in the World Health Organization tumor classification, there is uncertainty as to whether EPA is a distinct entity or a heterogenous group of tumours. The lesion usually presents as a slow-growing tumor of the skin and subcutaneous tissues of the head, neck, or extremity, of infants or young children. However, EPA has involved the testicle, deep muscle tissue as a neoplastic transformation of a larger existing benign cavernous hemangioma, bone and spleen, and has been found in adults. Some reports indicate a good prognosis but metastasis is occasionally seen.

- "Infantile hemangioendothelioma" is a rare benign vascular tumour arising from mesenchymal tissue and is usually located in the liver. It often presents in infancy with cardiac failure because of extensive arteriovenous shunting within the lesion. It is the third most common liver tumor in children, the most common benign vascular tumor of the liver in infancy, and the most common symptomatic liver tumor during the first 6 months of life. These hemangioendotheliomas have 2 growth phases: an initial rapid growth phase, which is followed by a period of spontaneous involution (usually within the first 12 to 18 months of life). Detection of the hemangioendothelioma within the first 6 months of life is attributed to the initial rapid growth during this time; however, the tumor has been detected with fetal ultrasonography. Histopathologically, there are 2 types of hepatic hemangioendotheliomas:

- Type I: Hemagioendotheliomas of this type have multiple vascular channels that are formed by an immature endothelial lining with stromal separation from bile ductules.

- Type II: These hemangioendotheliomas have an appearance that is more disorganized and hypercellular, and there are no bile ductules.

Hemangioendothelioma is used to describe a group of vascular neoplasms that may be considered benign as well as malignant, depending on the specific group member's activity.

The tumor largely affects children under 15 years of age and about 20% only are found in adults with nearly 60% involving males and 40% females (1). The most frequent locations are head and neck (orbit and nasopharynx), central nervous system, abdomen and retroperitoneum, pelvis, perineum, scrotum and prostate(1). Clinical symptoms are not specific and usually caused by local tumor compression and infiltration.

There are few early warning signs that a patient has a DSRCT. Patients are often young and healthy as the tumors grow and spread uninhibited within the abdominal cavity. These are rare tumors and symptoms are often misdiagnosed by physicians. The abdominal masses can grow to enormous size before being noticed by the patient. The tumors can be felt as hard, round masses by palpating the abdomen.

First symptoms of the disease often include abdominal distention, abdominal mass, abdominal or back pain, gastrointestinal obstruction, lack of appetite, ascites, anemia, and/or cachexia.

Other reported symptoms include unknown lumps, thyroid conditions, hormonal conditions, blood clotting, kidney or urological problems, testicle, breast, uterine, vaginal, or ovarian masses.

About 80% of pleural SFTs originate in the visceral pleura, while 20% arise from parietal pleura. Although they are often very large tumors (up to 40 cm. in diameter), over half are asymptomatic at diagnosis. While some researchers have proposed that a SFT occupying at least 40% of the affected hemithorax be considered a "giant solitary fibrous tumor", no such "giant" variant has yet been recognized within the most widely used pleural tumor classification scheme.

Some SFTs are associated with the paraneoplastic Doege–Potter syndrome, which is caused by tumor production of IGF-2.