HYPERTROPHIC OSTEOARTHROPATHY

Hypertrophic Pulmonary Osteoarthropathy              General Considerations Clinical syndrome consisting of clubbing of the fingers and toes Painful and swollen joints Symmetric periostitis especially involving the tibia and fibula, radius and ulna Most often secondary to an intrathoracic neoplasm or infection Primary form is called pachydermoperiostitis Etiology Release of vasodilators which are not metabolized by lung Increased flow through AV shunts Reflex peripheral vasodilation (vagal impulses) Hormones: estrogen, growth hormone, prostaglandin Thoracic Causes Malignant tumor (0.7-12%) Bronchogenic carcinoma (88%) Mesothelioma Lymphoma Pulmonary metastasis from Osteogenic sarcoma Melanoma Renal cell carcinoma Breast cancer Benign tumor Benign pleural fibroma Tumor of ribs Thymoma Esophageal leiomyoma Pulmonary hemangioma Pulmonary congenital cyst Chronic infection / inflammation Pulmonary abscess Bronchiectasis Blastomycosis TB (very rare) Cystic fibrosis Interstitial fibrosis Congenital heart disease with R-to-L shunt Extrathoracic Causes GI tract Ulcerative colitis Amebic + bacillary dysentery Intestinal TB Whipple disease Crohn disease Gastric ulcer Bowel lymphoma Gastric carcinoma Liver disease Biliary + alcoholic cirrhosis Posthepatic cirrhosis Chronic active hepatitis Bile duct carcinoma Benign bile duct stricture Amyloidosis, liver Abscess Undifferentiated nasopharyngeal carcinoma Pancreatic carcinoma Chronic myelogenous leukemia Clinical Findings Burning pain Painful swelling of limbs Stiffness of joints Ankles (88%) Wrists (83%) Knees (75%) Elbows (17%) Shoulders (10%) Fingers (7%) Peripheral neurovascular disorders Local cyanosis Areas of increased sweating Paresthesia Chronic erythema Flushing and blanching of skin Clubbing Hypertrophy of extremities (soft-tissue swelling) Location Tibia and fibula (75%) Radius and ulna (80%) Proximal phalanges (60%), femur (50%) Metacarpus and metatarsus (40%), humerus and distal phalanges (25%) Pelvis (5%) Unilateral (rare) Imaging Findings In diametaphyseal regions Periosteal proliferation of new bone First smooth, then undulating rough, most conspicuous on concavity of long bones (dorsal and medial aspects) Regression of periosteal reaction after thoracotomy Soft-tissue swelling ("clubbing") of distal phalanges Bone scan reveals changes early with greater sensitivity and clarity Symmetric diffusely increased uptake along cortical margins of diaphysis and metaphysis of tubular bones of the extremities Increased periarticular uptake (synovitis) Scapular involvement in 2/3 Mandible ± maxilla abnormal in 40%

Hypertrophic Osteoarthropathy. Bone scan (above left) shows symmetric, bilateral, linear uptake in the femurs and tibias (black arrows) while the conventional radiographs of the distal femurs and proximal tibias (above right) show smooth, wavy periosteal reaction primarily involving the metadiaphyseal portion of the bones (white arrows). retrieved from: http://www.learningradiology.com/archives2010/COW%20429-HPO/hpocorrect.htm