Diagnosis
Pancoast's (or superior sulcus) tumor.
Findings
MRA of the chest demonstrates significant narrowing of the mid left
subclavian artery from extrinsic compression. Chest x-ray
demonstrates an ill-defined opacity within the left apex with
destruction of the left medial second-third ribs. These findings
are confirmed on the CT images. MRI of the thoracic spine (STIR)
demonstrates abnormal increased T2 signal within the T6 and
thoracic to body consistent with tumor involvement. Additionally,
the left neural foramen at this site was widened secondary to tumor
extension.
Discussion
Pancoast's tumor represents 1-3% of all lung cancers and was
initially described in 1838 by Dr. Edward Hare. However, its name
is known from the radiologic description of the tumor in 1924 by
Dr. Henry Pancoast. Initially, the tumor was described in
association with Horner's syndrome and brachial plexus involvement
yet patient's may present with a wide range of symptoms such as
left shoulder or back pain and symptoms related to brachial plexus
involvement such such as paresthesias, weakness or muscular atrophy
within the affected upper extremity. Symptoms are typically
difficult to control which should increase suspicion for an
underlying neoplastic process. Less commonly, patient's may present
with paraneoplastic syndromes such as Cushing's syndrome,
hypercalcemia or hypertrophic osteoarthropathy. On chest xray,
apical capping of greater than 5 mm or posterior rib destruction
should prompt CT evaluation. Once discovered, radiologic staging of
the mass is paramount for treatment planning, for which MRI and PET
play the most important roles. Documentation of nodal metastatic
disease, involvement of the brachial plexus, vascular structures
and the thoracic spine and ribs is necessary. The presence of
Horner's syndrome, mediastinal and supraclavicular adenopathy and
vertebral body invasion portends a poorer prognosis.
Mediastinoscopy is utilized if mediastinal lymph nodes are in
question. Provided that there are no distant metastases or
extensive involvement of the spinous/paraspinous and vascular
structures, resection of the mass and the involved chest wall is
performed. The use of preoperative radiation therapy has proven
valuable to reduce tumor burden decreasing local recurrence and
increasing survival, with 5 years survival rates up to 35%.
Chemotherapy has proven of little value. Most tumors are squamous
cell carcinoma or adenocarcinoma; 3-5% are small-cell carcinomas.
1. Brant WE, Helms CA. Fundamentals of Diagnostic Radiology, Second
Edition. Lippincott Williams & Wilkins, Philadelphia, 1999, pp
387-8. 2. Detterbeck FC: Changes in the treatment of Pancoast
tumors. Ann Thorac Surg 2003 Jun; 75(6): 1990-7 3. Bhimji, S.
Pancoast Tumor. www.emedicine.com.