Laboratory Studies
Changes in liver function test results, CBC count, and electrolyte levels reflect visceral involvement of organs, including the lungs, heart, intestines, spleen, kidneys, and adrenal glands in patients with Weber-Christian disease.
Patients may present with a leukocytosis or leukopenia, anemia, or hypocomplementemia.
The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) is usually elevated, although the degree of elevation varies.
Serum and urine amylase and lipase levels are within the reference range, differentiating Weber-Christian disease from a panniculitis associated with pancreatic disease.
The alpha1-antitrypsin level is within the reference range, differentiating Weber-Christian disease from alpha1-antitrypsin panniculitis.
Imaging Studies
A chest radiograph is used to exclude systemic inflammatory or infectious granulomatous diseases (eg, sarcoidosis or tuberculosis).
Standard posteroanterior chest radiograph reveals extensive bilateral hilar and mediastinal lymph node enlargement not associated with a pulmonary abnormality in a patient with sarcoidosis.
Young male patient with fever and cough has a focal opacity in the left lower lobe that looks like a pneumonia. This is a case of primary tuberculosis.
Histologic Findings
Lobular panniculitis
Idiopathic lobular panniculitis (Weber-Christian disease) presents without vasculitis and is shown in the images below.
A portion of skin is examined in multiple sections and at various magnifications. The epidermis is intact; however, it is infiltrated by small numbers of lymphocytes. A mild infiltrate of lymphocytes and histiocytes are present in the upper dermis. The most prominent change is in the subcutaneous tissue, where a prominent infiltrate of histiocytes, smaller numbers of lymphocytes, and a few plasma cells in the subcutaneous adipose tissue are noted. Occasional foam cells are also evident, and, in places, histocytes surround lipid cysts. Small clusters of necrotic cells and scattered nuclear dust are noted. Minimal extension of this infiltrate into adjacent dense collagenous tissue is observed. (Courtesy of Milton J. Finegold, MD, Professor of Pathology and Pediatrics, Baylor College of Medicine, Houston, TX).
Other conditions without vasculitis include the following:
-
Histiocytic cytophagic panniculitis
-
Alpha1-antitrpysin deficiency panniculitis
Histopathologic features of alpha-1-antitrypsin deficiency panniculitis. (A) Scanning power shows a mostly lobular panniculitis. (B) Aggregations of neutrophils within the fat lobule are seen. (C) Neutrophils are interstitially arranged between collagen bundles of the deep reticular dermis. (A-C, hematoxylin-eosin stain; original magnifications: A, X 20; B, X 400; C, X 200).
-
Physical panniculitis, including cold-induced, traumatic (shown in the image below), chemical-induced, and factitial (shown in the image below)
Histopathologic features of late stage lesions of traumatic panniculitis. This lesion corresponds to the so-called nodular cystic fat necrosis or mobile encapsulated lipoma. A, Scanning power shows encapsulated and well-circumscribed lesion with no inflammatory infiltrate (arrow indicates area enlarged in B). B, At periphery of the lesion necrotic adipocytes appear as anucleated fat cells. (A and B, Hematoxylin-eosin stain; original magnifications: A, ×20; B, ×200.)
Histopathologic features of paraffinoma. A, Scanning power shows a mostly lobular panniculitis (arrow indicates area enlarged in B). B, Higher magnification demonstrates cystic spaces within the fat lobule surrounded by foamy histiocytes. (A and B, hematoxylin-eosin stain; original magnifications: A, ×20; B, ×200.)
-
Neonatal panniculitis, including sclerema neonatorum, neonatal subcutaneous fat necrosis (shown in the image below), and poststeroid panniculitis (shown in the image below)
Histopathologic features of subcutaneous fat necrosis of the newborn. (A) Scanning power shows a mostly lobular panniculitis (arrow indicates area enlarged in B). (B) Higher magnification demonstrated narrow needle-shaped clefts radially arranged and surrounded by histiocytes. (A and B, hematoxylin-eosin stain; original magnifications: A, X 20; B, X 200).
Histopathologic features of lipoatrophy secondary to subcutaneous injections of corticosteroids. (A) Low-power view showed small fat lobules (arrow indicates area enlarged in B). (B) Higher magnification demonstrates small adipocytes and prominent capillary proliferation, resembling embryonic fat. (A and B, hematoxylin-eosin stain; original magnifications: A, X 20; B, X 200).
-
Lobular panniculitis of systemic disease, including pancreatic panniculitis, lupus erythematosus, sarcoidosis, calcifying panniculitis of renal failure, lymphoma and leukemia, and infections
Nodular vasculitis (erythema induratum) presents with vasculitis.
Septal panniculitis
Conditions without vasculitis include the following:
-
Erythema nodosum
-
Scleroderma panniculitis
-
Lipodermatosclerosis
-
Eosinophilic fasciitis
-
Eosinophilic myalgia syndrome
Conditions with vasculitis include the following:
-
Superficial migratory thrombophlebitis
-
Polyarteritis nodosa
-
Cutaneous polyarteritis nodosa
Histopathologic stages observed in Weber-Christian disease
The first stage is characterized by an acute inflammatory reaction, in which lobules of fat are replaced by neutrophils, lymphocytes, and histiocytes.
In the second stage, macrophages migrate and phagocytose degenerated fat, forming characteristic "foam cells."
In the third stage, the foam cells are replaced by fibroblasts, and the inflammatory reaction is replaced by fibrotic tissue.
-
Lesion of erythema nodosum: tender, erythematous, nodular lesions located over the extensor surfaces of the legs.
-
Standard posteroanterior chest radiograph reveals extensive bilateral hilar and mediastinal lymph node enlargement not associated with a pulmonary abnormality in a patient with sarcoidosis.
-
Young male patient with fever and cough has a focal opacity in the left lower lobe that looks like a pneumonia. This is a case of primary tuberculosis.
-
Lesion of Weber-Christian disease: tender, erythematous, nodular lesions located over the limbs with cutaneous atrophy.
-
A portion of skin is examined in multiple sections and at various magnifications. The epidermis is intact; however, it is infiltrated by small numbers of lymphocytes. A mild infiltrate of lymphocytes and histiocytes are present in the upper dermis. The most prominent change is in the subcutaneous tissue, where a prominent infiltrate of histiocytes, smaller numbers of lymphocytes, and a few plasma cells in the subcutaneous adipose tissue are noted. Occasional foam cells are also evident, and, in places, histocytes surround lipid cysts. Small clusters of necrotic cells and scattered nuclear dust are noted. Minimal extension of this infiltrate into adjacent dense collagenous tissue is observed. (Courtesy of Milton J. Finegold, MD, Professor of Pathology and Pediatrics, Baylor College of Medicine, Houston, TX).
-
Magnification of previous specimen X 100.
-
Magnification of previous specimen X 200.
-
Histopathologic features of alpha-1-antitrypsin deficiency panniculitis. (A) Scanning power shows a mostly lobular panniculitis. (B) Aggregations of neutrophils within the fat lobule are seen. (C) Neutrophils are interstitially arranged between collagen bundles of the deep reticular dermis. (A-C, hematoxylin-eosin stain; original magnifications: A, X 20; B, X 400; C, X 200).
-
Histopathologic features of late stage lesions of traumatic panniculitis. This lesion corresponds to the so-called nodular cystic fat necrosis or mobile encapsulated lipoma. A, Scanning power shows encapsulated and well-circumscribed lesion with no inflammatory infiltrate (arrow indicates area enlarged in B). B, At periphery of the lesion necrotic adipocytes appear as anucleated fat cells. (A and B, Hematoxylin-eosin stain; original magnifications: A, ×20; B, ×200.)
-
Histopathologic features of paraffinoma. A, Scanning power shows a mostly lobular panniculitis (arrow indicates area enlarged in B). B, Higher magnification demonstrates cystic spaces within the fat lobule surrounded by foamy histiocytes. (A and B, hematoxylin-eosin stain; original magnifications: A, ×20; B, ×200.)
-
Histopathologic features of subcutaneous fat necrosis of the newborn. (A) Scanning power shows a mostly lobular panniculitis (arrow indicates area enlarged in B). (B) Higher magnification demonstrated narrow needle-shaped clefts radially arranged and surrounded by histiocytes. (A and B, hematoxylin-eosin stain; original magnifications: A, X 20; B, X 200).
-
Histopathologic features of lipoatrophy secondary to subcutaneous injections of corticosteroids. (A) Low-power view showed small fat lobules (arrow indicates area enlarged in B). (B) Higher magnification demonstrates small adipocytes and prominent capillary proliferation, resembling embryonic fat. (A and B, hematoxylin-eosin stain; original magnifications: A, X 20; B, X 200).
