Diagnosis is an important part in the management of nerve sheath tumor. The diagnosis helps the physician in identifying the presence of nerve sheath tumor, whether it is benign or malignant, and extent of metastasis and the stage of the disease. This will help the oncologist in evaluating the prognosis of the disease and also helps in creating an optimum treatment strategy. Early diagnosis is really important for favorable prognosis and is now possible due to highly sophisticated and computerized diagnostic techniques.
How Is Nerve Sheath Tumor Diagnosed?
Correct and early diagnosis of any tumor is a prerequisite condition for ensuring a favorable prognosis and strategizing correct treatment approach. It is also important for differentiating between the benign and malignant tumor as both requires different treatment approach and both have different prognosis. Further, the clinical symptoms presented by both the types are also different. A malignant nerve sheath tumor requires aggressive treatment approach while being nerve sheath tumor generally requires wait-and-watch approach provided the nerve sheath tumor does not hampering day-to-day activities of the patient. Further, the stage of the nerve sheath tumor should be diagnosed as it will also help in evaluating prognosis and treatment regimen.
Following are the diagnostic techniques used for the diagnosis of nerve sheath tumor:
Imaging Techniques– It is one of the most powerful technique for diagnosis any lesion or tumor in the body including nerve sheath tumor. These imaging techniques includes Computed Tomography scan, Magnetic Resonance Imaging and Ultrasonography. Out of these, MRI is said to the most effective diagnostic method for nerve sheath tumor. The imaging technique helps in location and extent of the tumor. Although ultrasonography is not a very reliable technique in nerve sheath tumor but when coupled with other techniques, it gives accurate results and helps in differentiating between the nerve sheath tumor and the swollen lymph node.
Physical Examination– A detailed skin or neurological examination is done by the physician at the initial stage to exclude the presence of other diseases with similar symptoms. Study of complete medical history of the patient also helps in diagnosis of nerve sheath tumor. The presence of lumps or mass is also examined during physical examination.
Electromyogram– It is the diagnostic tool that evaluates the activity of muscles. As the nerve sheath tumor compresses the nerves, the electrical conduction of the peripheral nerves gets compromised causing reduction of the muscular activity. In this technique, the needles are attached to the muscles and the muscular activity is calculated by the instrument.
Blood And Urine Tests– Although not a conclusive method for diagnosing the nerve sheath tumor, presence of some chemicals in the blood may help in evaluating abnormalities inside the body. Identification of potential biomarker for tumor is done through these lab testing.
Immunohistochemical Analysis– In recent time, this technique has paved is way in the diagnosis of cancer by identifying various proteins, presence of which may indicate the existence of cancer. The immunochemical profiles of the nerve sheath tumor such as SOX10, SOX2, and neurofibromin are assessed.
Myelography– In patients of nerve sheath tumors, who are unable to undergo the MRI, CT myelography is a desired option. It requires lumbar puncture and the contrasting agent is inserted. It is a technique wherein the real time X-ray is conducted. It is used to examine the nerves and related tissues with the help of contrasting agent.
Biopsy– Biopsy is an invasive procedure wherein the tissue is taken from the nerve sheath tumor and is examined under the microscope for any cellular abnormality. It is an important technique to confirm the present of malignant tumor. If the whole affected tissue is removed, then it is termed as excisional biopsy while incisional biopsy involves the extraction of a part of affected tissue. Another biopsy method is core biopsy or needle biopsy wherein a needle is used to extract the sample for analysis.
Nerve Conduction Study– While electromyogram involves the analysis of muscle strength, nerve conduction testing is done to identify the speed of the nerve impulse generated in the nervous system.
Various diagnostic techniques are used for diagnosing the nerve sheath tumor. These involves imaging techniques such as CT scan, MRI and ultrasonography, nerve conduction test, physical examination, biopsy, myelography, electromyogram, blood test and immunohistochemical analysis.