A 59-year-old man with ischemic pancreatic disease, polyarthritis, and cutaneous nodules has shown histopathologic findings indicative of disseminated fat necrosis in a percutaneous biopsy specimen from the right knee. The histopathologic findings in the synovium included necrotic fat cells, distorted fat cells and adjacent lymphocytes, lipid laden histiocytes, and giant cells. In prior histopathologic studies of the joint involvement associated with this disorder, fat cell necrosis has been found only in the periarticular tissues, and the synovium has appeared normal or showed nonspecific inflammation. However, the present study shows that the synovial membrane may also be the site of fat necrosis and an associated inflammatory reaction; thus patients with this disorder may manifest arthritis in addition to periarthritis.Disseminated fat necrosis is a rare complication of pancreatic disease marked by cutaneous nodules, joint pain, and increased serum amylase and lipase (1). The diagnosis is established by the characteristic histopathology: foci of necrotic fat cells with disrupted shadowy walls and a surrounding zone of acute or chronic inflammation (2). The joint pain experienced by patients with this entity has generally been attributed to a periarthritis; fat necrosis has been noted only in periarticular tissues (3-9). However, we have recently observed fat cell necrosis in the synovial membrane from the right knee of a 59-year-old man who had ischemic pancreatitis secondary to atherosclerosis of the abdominal arteries. CASE REPORTCL, a 59-year-old white man, developed an illness characterized by episodes of fever, arthritis, and cutaneous nodules in 1972. These recurrent attacks would persist for days or weeks and recur irregularly. The joint disease was polyarticular with a predilection for the metacarpophalangeals of the hands, knees, and ankles. The involved joints were swollen, erythematous, and unresponsive to treatment with aspirin, indomethacin, and phenylbutazone. The cutaneous nodules were erythematous and developed most frequently over the arms, abdomen, and legs.Findings that suggested t h e skin a n d joint involvement were related to pancreatic disease were noted during hospitalization for a severe episode of arthritis in January 1975. A biopsy specimen from a cutaneous nodule showed foci of necrotic fat cells, and the serum amylase and the serum lipase were elevated. Studies to detect a pancreatic neoplasm were initiated as there were no symptoms suggestive of acute pancreatitis or abdominal trauma. An upper gastrointestinal series, barium enema, cholecystogram, intravenous cholangiogram, and isotope scan of the pancreas were not helpful; abdominal arteriography was planned. However, during the course of these evaluations, the patient's joints had shown moderate improvement, and he refused this critical study.

Two patients with arthritis of the knee joints associated with cutaneous polyarteritis have been followed for 20 and 5 years. The arthritis is characterized by mild to moderate pain and stiffness and inflammatory joint effusions with predominantly polymorphonuclear leukocytes. Despite its chronicity, there has been no clinical or radiologic evidence of joint destruction. Necrotizing inflammation was seen in arteries of the deep skin but not in the small vessels observed in the synovial biopsy specimens.Cutaneous polyarteritis is characterized by a variety of cutaneous lesions, a benign course, and necrotizing arteritis (1-3). The skin findings, which are often localized to the lower extremities, most frequently include painful erythematous nodules, ulcerations, and livedo reticularis. Cutaneous polyarteritis, however, is not strictly a cutaneous disorder, because arthralgia, arthritis and peripheral neuropathy, and fever may also occur. The generally benign course may be brief, protracted over many years, or episodic with spontaneous or corticosteroid-induced remissions (3). In many patients the white blood cell count and/or erythrocyte sedimentation rate is increased. Diagnosis is confirmed by an excision biopsy of the skin deep enough to detect necrotizing inflammation of arteries in the deep dermis or subcutaneous tissue. These histopathologic findings are identical with those of the skin lesions of systemic polyarteritis. However the predominant cutaneous findings, usual absence of visceral lesions, and benign course of cutaneous polyarteritis are the basis of its delineation from systemic polyarteritis (1-3)We have observed a chronic nondestructive arthritis of the knees in 2 patients with cutaneous polyarteritis for 20 and 5 years. This report describes the clinical features, light microscopic findings in the skin, and light and electron microscopic findings in synovial biopsy specimens of this unusual arthritis. Possible reasons for the benign nature of this joint disease are presented. CASE REPORTS Patient AThis 68-year-old white man developed painful tender skin lesions over the legs and ankles at the outset of his illness, which has now persisted for 20 years. Hospital evaluation at onset showed that he was emaciated, febrile, and normotensive. There were multiple hemorrhagic, exquisitely tender, and indurated lesions measuring 1.5 to 2 cm in diameter over the anterior surface of the legs, the malleoli, and the dorsurn of the feet. Except for pitting edema which extended to the knees

No abstract