Pancreatic panniculitis - Skin
The condition occurs in the setting of acute pancreatitis or chronic pancreatitis and in the context of pancreatic acinar carcinoma, where panniculitis may herald metastatic disease. Pancreatic panniculitis can be a presenting feature of subclinical pancreatitis in which elevated amylase and lipase may be the only laboratory abnormality. Sometimes the cutaneous eruption precedes the typical presentation of pancreatitis by weeks to months. With necrosis of the periarticular fat, patients may also experience arthritis involving the ankles and knees. Other associated findings include fever and abdominal pain, especially in patients with acute pancreatitis. Rarely, pancreatic panniculitis is associated with necrosis of the abdominal fat, necrosis of bone marrow fat, pleural effusions, mesenteric thrombosis, and eosinophilia. Other less frequent pancreatic abnormalities that have been described in association with pancreatic panniculitis include pancreas divisum, pancreatic pseudocysts, vasculopancreatic fistulas, traumatic pancreatitis, and pancreatitis secondary to sulindac intake.
Nodules develop from fat necrosis related to release of trypsin, lipase, amylase, and other lipolytic enzymes from the pancreas into the circulation, resulting in formation of triglycerides from glycerol esters in the pannus, which leads to necrosis.
Pancreatic panniculitis may be differentiated from other types of panniculitis by the microscopic presence of ghost cells with loss of adipocyte nuclei and fine basophilic granular material in the subcutis. The fatty acids combine with calcium to form soaps, a process called saponification.
Resolution of the nodules with scarring may occur within weeks to months after treatment of pancreatitis or after resection of pancreatic carcinoma
Immunocompromised Patient Considerations:
A case of pancreatic panniculitis has been reported in association with primary HIV infection and a hemophagocytic syndrome.
Pediatric Patient Considerations:
There is one case report of a child with systemic lupus erythematosus treated with prednisone, azathioprine, and hydrochlorothiazide who developed pancreatitis and associated subcutaneous nodular fat necrosis and calcinosis cutis.
M79.3 – Panniculitis, unspecified
403416005 – Panniculitis secondary to pancreatic disease
- Alpha-1 antitrypsin deficiency panniculitis also presents with tender erythematous nodules on the lower trunk, buttocks, and thighs that ulcerate and drain. Associated with an alpha1-antitrypsin deficiency (protease inhibitor deficiency), the condition may occur in the setting of chronic liver disease with cirrhosis, emphysema, pancreatitis, and vasculitis. Microscopic findings include a predominantly neutrophilic panniculitis with liquefactive fat necrosis. "Skip areas" of normal intervening fat may be seen.
- Nodular vasculitis (erythema induratum) presents as tender erythematous nodules on posterior lower legs that ulcerate. Microscopically, a mixed lobular and septal panniculitis with vasculitis involving small- to medium-sized arteries is observed. Erythema induratum is associated with tuberculosis.
- Panniculitis due to injection of foreign material into the skin (factitial panniculitis) – Self-injection of various oils (olive, mineral, castor, sesame) causes panniculitis presenting with erythematous, often draining, nodules at sites of injection. Mixed septal and lobular inflammation and varying degrees of fat necrosis are present, along with a Swiss cheese appearance of the pannus with varying sizes of cystic spaces.
- Polyarteritis nodosa is a small- and medium-vessel vasculitis that presents with erythematous and purpuric nodules on the lower extremities. Livedo reticularis is a common associated finding.
- Cytophagic histiocytic panniculitis – subcutaneous nodules that ulcerate and drain, with fever, hepatosplenomegaly, cytopenias, liver failure, intravascular coagulation, and hemorrhage. Microscopically, there is lobular panniculitis with "beanbag" cells representing cytophagocytosis by macrophages.
- Erythema nodosum does not typically occur in the context of pancreatic disease. Tender nodules occur on the anterior legs and do not ulcerate or drain. Histologically represents a septal panniculitis with no necrosis of adipocytes.
- Lupus panniculitis – tender erythematous plaques and nodules occurring most commonly on the upper body. Plaques also heal with disfiguring scars. The microscopic appearance is characterized by hyalinization as well as aggregates of lymphocytes in the pannus. Interface dermatitis and dermal mucin may also be present.