Peripheral primitive neuroectodermal tumor: a case report

Abstract

Background Primitive neuroectodermal tumors are extremely rare and highly aggressive malignant small round cell tumors that arise from the primitive nerve cells of the nervous system or outside it. These tumors share similar histology, immunohistologic characteristics, and cytogenetics with Ewing’s sarcoma. Peripheral primitive neuroectodermal tumors of the chest wall are rare malignant tumors seen in children and young adults. Case presentation We report a rare case of peripheral primitive neuroectodermal tumor in a 4-year-old Albanian girl with a mediastinal tumor and an unusual clinical presentation. She was initially treated for acute polyradiculoneuritis (Guillain–Barré syndrome) owing to pain, weakness in the lower limbs, and walking difficulty, as well as severe irritability. During the second week of treatment, the child began to experience dry cough, chest discomfort, and worsening dyspnea. Chest radiography, chest computed tomography, and contrast-enhanced computed tomography demonstrated a large mass in the right hemithorax that was derived from the posterior mediastinum with expansive growth in all directions and that shifted the mediastinal structures in the anterolateral left direction. Consequently, histopathology and immunohistochemical examination of the markers S-100, CD99, and Ki-67 showed that the tumor cells stained positively for S-100 and CD99. The proliferative index measured by Ki-67 was approximately 20%, which suggested primitive neuroectodermal tumor. Conclusions Even though other diseases, including leukemia, lymphoma, and neuroblastoma, may be accompanied by musculoskeletal manifestations in children, other solid tumors, such as peripheral primitive neuroectodermal tumors, should be considered in the differential diagnosis in any child presenting with musculoskeletal symptoms.

Oral primitive neuroectodermal tumor associated with mandibular lymphadenopathy in three-year-old female Indonesian children: A rare case report

“…Peripheral PNETs share similarities with central PNETs in terms of histology, showing small round blue cells and a high proliferation rate. Peripheral PNETs also showed a Homer-Wright rosette formation similar to PNETs with mitotic figures, necrosis, and endothelial hyperplasia [8,9] . The incidence of PNET, in general, is 0.15 per 100,000 children aged 0-4 years and 0.15 per 100,000 children aged 5-9 years.…”

Renal primitive neuroectodermal tumor: A rare case with a good prognosis

“…CD99 is a monoclonal antibody that recognizes p30/32 glycoprotein and contributes to the identification of rPNET cells ( 7 ). CD99 is detected in almost all rPNET ( 8 ). However, it has also been reported that CD99 is expressed in small-cell carcinoma, Wilms’ blastoma, and non-Hodgkin lymphoma ( 9 ).…”

Neurogenic tumours of the posterior mediastinum and differential diagnosis considerations

“…The differential diagnosis in the posterior mediastinum therefore may include Ewing sarcoma/peripheral neuroectodermal tumour (ES/PNET), rhabdomyosarcoma, lymphoblastic lymphoma, poorly differentiated synovial sarcoma (SyS), and non‐Hodgkin lymphoma, and may be particularly challenging in undifferentiated neuroblastomas lacking neurofibrillary stroma or rosette formation. ES/PNET may arise in the mediastinum, including the posterior mediastinum 2,24,25 . Distinguishing ES/PNET from neuroblastoma is generally accomplished by immunohistochemistry (Table 2).…”

“…ES/ PNET may arise in the mediastinum, including the posterior mediastinum. 2,24,25 Distinguishing ES/PNET from neuroblastoma is generally accomplished by immunohistochemistry (Table 2). ES/PNET stains for CD99 and NKX2.2 (Figure 3A,B), but both markers may rarely be positive in neuroblastoma.…”