Peripheral Nerve Sheath Tumor



Peripheral Nerve Sheath Tumor







Key Facts


Terminology



  • Peripheral nerve sheath tumor (PNST)


  • Synonyms: Malignant schwannoma, neurofibrosarcoma, neurogenic sarcoma


Clinical Issues



  • These tumors are more common in posterior mediastinum but can also occur in anterior mediastinum


  • Symptoms



    • Chest pain


    • Cough


    • Dyspnea


    • Neurofibromatosis


  • Prognosis



    • These tumors follow aggressive behavior, and prognosis is poor


    • Worse prognosis in patients with neurofibromatosis


  • Incidence



    • Unusual in mediastinal location


    • May account for approximately 5% of all mediastinal tumors


Top Differential Diagnoses



  • Neurofibroma


  • Leiomyosarcoma


  • Solitary fibrous tumor


Diagnostic Checklist



  • Solid spindle cellular proliferation


  • Perivascular hyalinization


  • Hemorrhage &/or necrosis


  • Nuclear atypia and mitotic activity






Mediastinal peripheral nerve sheath tumor shows a solid spindle cell proliferation with a vague herringbone-like pattern of growth.






High-power view of a mediastinal peripheral nerve sheath tumor shows more epithelioid areas with cellular pleomorphism, nuclear atypia, and mitotic activity image.


TERMINOLOGY


Abbreviations



  • Peripheral nerve sheath tumor (PNST)


Synonyms



  • Malignant schwannoma, neurofibrosarcoma, neurogenic sarcoma


Definitions



  • Malignant tumor of neural sheath origin


ETIOLOGY/PATHOGENESIS


Etiology



  • These tumors may occur as manifestation of neurofibromatosis (von Recklinghausen disease)


  • PNST may also occur post radiation


CLINICAL ISSUES


Epidemiology



  • Incidence



    • Unusual in mediastinal location


    • May account for approximately 5% of all mediastinal tumors


  • Age



    • More common in adults in 3rd, 4th, and 5th decades of life


  • Gender



    • No apparent gender predilection


    • Patients with neurofibromatosis are commonly male and young adults


Site



  • More common in posterior mediastinum but can also occur in anterior mediastinum


Presentation



  • Chest pain


  • Cough


  • Dyspnea


  • Neurofibromatosis


Treatment



  • Surgical approaches



    • Complete surgical resection


  • Adjuvant therapy



    • Radiation &/or chemotherapy will be determined on individual basis and depending on extent of tumor at time of diagnosis


Prognosis



  • Tumors follow aggressive behavior, and prognosis is poor


  • Worse prognosis in patients with neurofibromatosis


MACROSCOPIC FEATURES


General Features



  • Lobulated large but not encapsulated tumors


  • Light tan in color


  • Areas of necrosis and hemorrhage may be seen


Size



  • Usually > 5 cm in diameter


MICROSCOPIC PATHOLOGY


Histologic Features



  • Solid spindle cellular proliferation


  • Wavy or comma-shaped nuclei


  • Nuclear palisading


  • Tactoid differentiation


  • Cellular pleomorphism with mitotic activity


  • Areas of hemorrhage &/or necrosis may be seen


  • Perivascular hyalinization



  • Heterologous elements may be seen



    • Muscle, cartilage, bone


DIFFERENTIAL DIAGNOSIS

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Jul 9, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Peripheral Nerve Sheath Tumor

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