Primary intraspinal peripheral primitive neuroectodermal tumors (pPNET) are extremely rare. We report a 10-month-old girl presented with rapidly progressive paraparesis and raised cerebrospinal fluid protein. A magnetic resonance image demonstrated an intramedullary mass from C3 to T3 level and intradural extramedullary nodules in the lumbosacral area. Surgery was performed with partial tumor removal and histologic examination revealed a small round cell tumor and immunohistochemical characteristics of pPNET. She died due to tumor progression at four months after initial diagnosis. This case has been reported to raise awareness among clinicians to include the possibility of intraspinal tumors in the differential diagnosis of progressive neurological deficits mimicking Guillain-Barre syndrome.
Diagnosis, Differential ; Guillain-Barre Syndrome ; Humans ; Infant ; Magnetic Resonance Spectroscopy ; Neuroectodermal Tumors ; Neuroectodermal Tumors, Primitive ; Neuroectodermal Tumors, Primitive, Peripheral ; Paraparesis

The MRI appearances of 7 adult patients with pathologically proven intracranial primitive neuroectodermal tumors (PNET) were retrospectively analyzed. The MRI features were compared with findings in pathology and surgery. In this group, the tumor masses were most commonly found in the semisphere of cerebrum and in the vermis of cerebellum. They were relatively large and 4 were in lobulated shape. All of them had well-defined margins. MR images showed the tumors to be mildly or obviously hypointense on T1-weighted images and hyperintense on T2-weighted images. Most masses had heterogeneous appearances with some cystic and necrotic areas. Intratumoral haemorrhage and focal calcification were occasionally seen. Mostly, there was no or only mild surrounding edema. Marked inhomogeneous contrast enhancement on MRI was seen in 6 cases except one. Two patients with multiple intracranial metastases were revealed on MR images. In this series, there was good correlation between MRI features and findings in pathology and surgery. These results showed that certain MRI features might suggest the diagnosis of intracranial PNET in adults. MRI is an effective technique to detect these tumors and is helpful to treatment planning and follow-up.
Brain Neoplasms/*diagnosis ; Brain Neoplasms/*pathology ; *Magnetic Resonance Imaging ; Neuroectodermal Tumors, Primitive/*diagnosis ; Neuroectodermal Tumors, Primitive/*pathology ; Retrospective Studies

Accurate diagnosis of pancreatic solid lesions is often difficult using conventional imaging modalities. With the recent introduction of contrast-enhanced harmonic endoscopic ultrasound (CEH-EUS), it is now possible to evaluate the microvascular environment and dynamic enhancement of a variety of pancreatic lesions. With CEH-EUS, three patterns of pancreatic lesion enhancement compared with the normal pancreatic tissue (fast, simultaneous, or slow), two washout patterns (fast or slow) and two distribution patterns (homogeneous, inhomogeneous) can be described. By evaluating the microvasculature, enhancement speed, and washout pattern, CEH-EUS may help to differentiate pancreatic adenocarcinoma from other masses and differentiate between pancreatic neuroendocrine tumor (pNET) and inflammatory masses. The finding of a hyperenhancing lesion on CEH–EUS, both with homogeneous and inhomogeneous patterns, was a strong predictor of histology different from adenocarcinoma (94% positive predictive value). pNET was the most common hyperenhancing lesions overall. Although CEH-EUS is useful for ruling out pancreatic ductal adenocarcinoma, making the differential diagnosis between pNETs and pseudotumoral pancreatic masses is difficult because both may share an isovascular or hypervascular appearance. Currently the interpretation of CEH-EUS findings is examiner-dependent. In the future, digital image analysis by image-processing techniques should allow more objective interpretation.
Adenocarcinoma ; Diagnosis ; Diagnosis, Differential ; Microvessels ; Neuroectodermal Tumors, Primitive ; Neuroendocrine Tumors ; Pancreatic Ducts ; Ultrasonography*

We report the case of a 16-year-old boy with a solid pancreatic mass which proved to be a nonfunctioning, malignant pancreatic neuroendocrine tumor (PNET). In pediatric patients, malignant pancreatic tumors are rare, especially malignant PNET. When dynamic contrast enhanced MRI showed a well enhancing solid pancreatic tumor on arterial and delayed phases and combined with malignant features, such as vascular invasion, invasion of adjascent organs, and lymphadenopathy, we should include malignant pancreatic neuroendocrine tumor in the differential diagnosis of childhood pancreatic tumors.
Adenoma, Islet Cell ; Adolescent ; Child ; Diagnosis, Differential ; Humans ; Lymphatic Diseases ; Neuroectodermal Tumors, Primitive ; Neuroendocrine Tumors

Medulloepithelioma, a rare tumor, arises from the epithelium of the medullary tube. In this article, we present a 3-year-old boy who suffered from secondary glaucoma, initially presumed the primary disease was endophthalmitis. Subconjunctival mass was later found, pathologically proved to be medulloepithelioma. We discuss the patient management with emphasis on the early signs of examination and the role of ultrabiomicroscopy (UBM) in evaluating pediatric secondary glaucoma and in influencing the management of patients with medulloepithelioma.
Child, Preschool ; Ciliary Body ; pathology ; Eye Neoplasms ; diagnosis ; Glaucoma ; Humans ; Male ; Neuroectodermal Tumors, Primitive ; diagnosis

Primitive neuroectodermal tumours (PNETs) arise from pluripotent neural crest cells and are classified as either central or peripheral. Peripheral PNETs (pPNETs) arise outside the central nervous system and sympathetic chain. These rare neoplasms comprise only 1% of all sarcomas and have highly aggressive biological behaviour and dismal prognosis. Adolescents and young adults are typically affected. Only isolated case reports on pPNETs appearing in both typical and atypical sites can be found in the literature. Timely diagnosis of pPNETs is a challenge to clinicians and radiologists due to the disease's insidious onset and variable locations, coupled with the limited studies that focus on the imaging features of pPNETs. Hence, this article serves to review the imaging features of this rare tumour.
Contrast Media ; Diagnosis, Differential ; Diagnostic Imaging ; Humans ; Neuroectodermal Tumors, Primitive, Peripheral ; diagnosis

The authors present our surgical experiences of five patients with tumors in and surrounding the pontomedullary region. The tumors were located in the pons in two patients, cerebellomedullary fissure in two and fourth ventricle extending in bilateral cerebellomedullary fissure in one. After midline suboccipital craniectomy, tumors in the pons were removed via safe entry route such as median sulcus of the 4th ventricle and suprafacial triangle. Tumors in the 4th ventricle extending cerebellomedullary fissure were resected via transvermian and transcerebellomedullary fissure approach. After surgery, the majority of the initial symptoms were relieved to almost normal state except transient facial weakness and nystagmus for 3 months in one, transient exacerbation of the gait disturbance in two. All the five patients showed different histological diagnosis: epidermoid, metastasis, medulloepithelioma, anaplastic astrocytoma, and malignant lympoma, respectively. It is suggested that tumors in and surrounding the pontomedullary area might be removed without significant neurologic sequelae via safe entry route.
Astrocytoma ; Diagnosis ; Fourth Ventricle ; Gait ; Humans ; Neoplasm Metastasis ; Neuroectodermal Tumors, Primitive ; Pons

Medulloblastoma is a common pediatric tumor typically diagnosed before the age of fifteen. Initial therapy includes surgical resection and radiation of the entire neuro-axis. Recurrence is common and typically occurs within 2 years of initial diagnosis. Those fitting Collin's Law is considered tumor-free. We report a case of single supratentorial recurrence 13 years after initial diagnosis. Here we present a 22 year old male presenting 13 years after initial diagnosis with isolated septum pellucidum recurrence. He underwent complete resection of the tumor. Medulloblastoma is a common in the pediatric population. Late recurrence to the ventricular system is uncommon. Long term follow-up is recommended in these patients.
Diagnosis ; Follow-Up Studies ; Humans ; Jurisprudence ; Male ; Medulloblastoma* ; Neuroectodermal Tumors, Primitive ; Recurrence* ; Septum Pellucidum

Primitive neuroectodermal tumors (PNETs) are primitive neuroblastic tumors that, unlike neuroblastomas, arise outside the autonomic nervous system, but very few cases with a renal origin have been described. The immunohistochemical staining for CD99 is useful in their diagnosis. A case of renal primitive neuroectodermal tumor, in a 61- year-old man presenting with a painless gross hematuria is reported. The immunohistochemical staining of the renal mass was strongly positive for CD99.
Autonomic Nervous System ; Diagnosis ; Hematuria ; Immunohistochemistry ; Kidney* ; Neuroblastoma ; Neuroectodermal Tumors, Primitive*

Small cell osteosarcoma is a rare form of osteosarcoma and the histological differential diagnosis from other small round cell tumors (SRCTs) is difficult. The immunohistochemical stain for MIC2 has been considered an useful diagnostic marker for Ewing's sarcoma and primitive neuroectodermal tumors but recently, other SRCTs such as malignant lymphoma and embryonal rhabdomyosarcoma also showed positive reaction. Therefore, the usefulness of MIC2 must still be proven. We experienced a case of small cell osteosarcoma of the mandible in a 25-year-old man. Histologically, the tumor consisted of small round cells that resembled those of Ewing's sarcoma. Immunohistochemically, the tumor cells expressed diffuse strong positive reaction for MIC2 gene products. However, the scanty foci of lacy osteoid material between the tumor cells seemed to be diagnostic of osteosarcoma. The histologic and immunohistochemical findings of this case suggest close relationship between small cell osteosarcoma and Ewing's sarcoma.
Adult ; Diagnosis, Differential ; Humans ; Lymphoma ; Mandible ; Neuroectodermal Tumors, Primitive ; Osteosarcoma* ; Rhabdomyosarcoma, Embryonal ; Sarcoma, Ewing*