Pancoast’s Tumor Syndrome

THE CLINICAL SYNDROME

• The development of Pancoast's tumor syndrome is caused by the local growth of a tumor that extends directly from the apex of the lung into the brachial plexus.
• These tumors typically involve the first and second thoracic nerves in addition to the eighth cervical nerve, and they produce a classic clinical syndrome that is characterized by severe arm pain and, in some patients, Horner's syndrome.
• This syndrome is characterized by the fact that the patient has an abnormality in the eighth cervical nerve.
• The first and second ribs are frequently the ones to be destroyed as well.
• The diagnosis is typically delayed, and in the meantime, patients are frequently incorrectly treated for cervical radiculopathy or primary shoulder disease.
• This continues until the correct diagnosis can be made.

SIGNS AND SYMPTOMS

• Patients who are affected by Pancoast's tumor syndrome often describe experiencing pain that is localized to the supraclavicular region as well as in the upper extremities.
• Because the tumor grows from below, it initially affects the lower portion of the brachial plexus.
• This results in pain in the upper thoracic and lower cervical dermatomes. As the tumor spreads into the brachial plexus, the patient experiences a neuropathic type of pain that may become more intense or monotonous.
• Because movement of the neck and shoulders makes the pain worse, patients typically try to avoid movements that involve those areas.
• Frozen shoulder is a common complication that can make the diagnosis more difficult.
• Horner's syndrome is a medical condition that can develop as the disease worsens.

TESTING

• The magnetic resonance imaging (MRI) of the cervical spine and the brachial plexus should be performed on all patients who present with brachial plexopathy.
• This is especially important for patients who do not have a clear history of any prior trauma to the area.
• Imaging with computed tomography (CT) and/or ultrasound is a viable alternative to MRI in the event that the latter modality cannot be used.
• Positron emission tomography might be able to shed some light on the questionable nature of masses found in these regions.
• Electromyography (EMG) and nerve conduction velocity testing are very sensitive diagnostic tools, and an experienced electromyographer can determine which part of the plexus is dysfunctional using these tools.
• It is recommended that chest radiography with apical lordotic views or CT scanning through the apex of the lung be performed on all patients who have a significant smoking history and a suspicion that they have Pancoast's tumor or another tumor of the brachial plexus.
• In the event that the diagnosis is uncertain, screening laboratory tests, which include a complete blood count, erythrocyte sedimentation rate, antinuclear antibody testing, and automated blood chemistry, should be carried out in order to eliminate other potential reasons for the patient's pain.

DIFFERENTIAL DIAGNOSIS

• The brachial plexopathy that is associated with Pancoast's tumor syndrome can be confused with symptoms caused by conditions that affect the cervical spinal cord, the bony cervical spine, or the disk.
• The clinician should be aware that more than one pathologic process may be contributing to the patient's symptoms.
• Appropriate testing, such as an MRI and an EMG, can help sort through the myriad of possibilities, but the clinician should also be aware of this fact.
• The symptoms of syringomyelia, a tumor of the cervical spinal cord, and a tumor of the cervical nerve root as it exits the spinal cord (such as schwannoma) can develop gradually over time, making it challenging to diagnose.
• Patients who present with brachial plexopathy but have no obvious history of trauma should have Pancoast's tumor at the top of their list of possible diagnoses.
  • This is especially true if the patient has a past of tobacco use.
• It is possible for brachial plexopathy to be the presenting symptom of a lateral herniated cervical disk, a metastatic tumor, or cervical spondylosis if these conditions cause significant nerve root compression. In extremely rare cases, an infection that affects the tip of the lung can cause the plexus to become compressed and irritated.

TREATMENT

Drug Therapy

Opioid Analgesics

• Opioid analgesics are generally considered to be the treatment of choice for the pain that is associated with Pancoast's tumor syndrome.
• In spite of the fact that opioid analgesics do not usually provide satisfactory relief for neuropathic pain, it is important to at least give them a shot when there are no other treatment options available because the pain is so severe.
• It is reasonable to begin treatment with the administration of a powerful opioid with a short duration of action, such as oxycodone.
• There is also the possibility of using methadone or morphine with an immediate release.
• In addition to nonsteroidal anti-inflammatory drugs and adjuvant analgesics, these medications may also be used in combination with one another.

Gabapentin

• Gabapentin is a medication that is utilized in the treatment of neuritic pain associated with Pancoast's tumor syndrome.
• The initial dose of gabapentin is 300 milligrams taken before going to bed for a period of two nights.
• The patient should be warned about the possibility of experiencing adverse effects, such as dizziness, sedation, confusion, and rash.
• The dose of the medication is then gradually increased by 300 milligrams over the course of two days, with each day's total dose being divided evenly into the previous day's dose.
• This process is repeated until either pain relief is achieved or a total dose of 2400 milligrams per day is reached.
• At this stage, blood values are measured, and the medication is carefully titrated upward using 100-mg tablets.
• This is done in the event that the patient has experienced some relief from their pain.
• It is extremely uncommon for a daily dose to be higher than 3600 mg.

Pregabalin

• Pregabalin is a reasonable alternative to gabapentin, and some patients find that it is better tolerated than gabapentin.
• The typical starting dose of pregabalin is 50 milligrams taken three times a day.
• This dose can be increased to a maximum of 100 milligrams taken three times a day if the patient's side effects permit.
• Patients whose kidney function is compromised should have their dosage of pregabalin decreased.
• The kidneys are the primary organs responsible for excreting the drug.

Invasive Therapy

Brachial Plexus Block

• A brachial plexus block with a local anesthetic and steroid is a fantastic adjunct to the treatment of Pancoast's tumor syndrome that involves medication.
• During the process of titrating medications to their optimal levels, this technique provides rapid pain relief.
• To perform the initial block, preservative-free bupivacaine is combined with methylprednisolone and injected into the affected area.
• The procedure for performing subsequent daily nerve blocks is very similar; the only difference is that a lower dose of methylprednisolone is used.
• This method can also be utilized to control pain that hasn't fully settled in.

Radiofrequency Destruction of the Brachial Plexus

• Using biplanar fluoroscopic guidance, a radiofrequency lesion can be created to damage the brachial plexus, which will result in its destruction.
• Only those patients for whom the aforementioned treatments have been unsuccessful are candidates for this procedure.

Dorsal Root Entry Zone Lesioning

• When all of the aforementioned treatment options have been tried without success, the neurosurgical procedure known as dorsal root entry zone lesioning is the one that is recommended for patients who suffer from intractable brachial plexopathy that is associated with Pancoast's tumor.
• This is a significant neurosurgical operation, and there are significant risks associated with it.

Other Neurosurgical Options

• Cordotomy, deep brain stimulation, and thalamotomy have all been tried, and their degrees of success have all been different.

Physical Modalities

• Patients who are diagnosed with Pancoast's tumor syndrome typically require both physical and occupational therapy as an essential component of their treatment plan.
• The goal of this treatment is to preserve the patient's function while also providing pain relief.
• Shoulder abnormalities, such as subluxation and adhesive capsulitis, need to be treated with a great deal of intensity.
• It is essential to participate in occupational therapy to receive assistance with activities of daily living if one wishes to forestall a further decline in function.

COMPLICATIONS AND PITFALLS

• It can be difficult to find relief from the pain caused by Pancoast's tumor syndrome. It's possible that none of the recommended medications will work, or even just one of them.
• Patients suffering from Pancoast's tumor syndrome, a condition in which the pain cannot be controlled, should be hospitalized on a priority basis because it can lead to suicidal thoughts.
  • Because of the pain and dysfunction that are associated with brachial plexopathy as a result of
• Pancoast's tumor, aggressive treatment is required. It is therefore essential to make an accurate diagnosis of the underlying cause.

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