A. Components of Syndrome

1. Shoulder and arm pain
2. Horner's Syndrome
   1. Ptosis
   2. Miosis
   3. Anhidrosis
   4. Invasion of paravertebral sympathetic chain and inferior cervical (stellate) ganglion
3. Weakness and atrophy of muscles of hand
4. Due to various mass lesions, primarily lung carcinomas
5. Neoplasms which cause the syndrome may be called Pancoast Tumors

B. Malignant Causes

1. Primary Neoplasms (most common)
   1. Primary bronchogenic carcinoma
   2. Other thoracic neoplasms: mesothelioma, adenoid cystic carcinoma, hemangiopericytoma
2. Metastatic Neoplasms
   1. Carcinoma of the larynx or thyroid
   2. Cervical carcinoma
   3. Urinary bladder carcinoma (transitional cell)
3. Hematologic Neoplasms
   1. Lymphoma
   2. Plasmacytoma
   3. Lymphomatoid granulomatosis

C. Infectious Causes

1. Bacterial
   1. Staphylococcal pneumonia
   2. Pseudomonal pneumonia
2. Atypical Bacterial
   1. Tuberculosis
   2. Actinomycosis
3. Fungal
   1. Aspergillosis
   2. Allescheriasis
   3. Cryptococcosis
4. Parastitic: hydatid cyst

D. Miscellaneous Causes

1. Cervical rib syndrome
2. Pulmonary amyloidoma

References

1. Arcasoy SM and Jett JR. 1997. NEJM. 337(19):1370