Weber-Christian panniculitis: a review of 30 cases with this diagnosis

Panniculitic primary cutaneous gamma delta T-cell lymphoma with concomitant features of autoimmune disease emphasizing a pathophysiologic continuum of lupus profundus with the panniculitic T cell lymphomas

Certain T-cell lymphomas exhibit unique homing properties of the neoplastic lymphocytes for the subcutaneous fat. There are two primary forms of subcutaneous panniculitic lymphomas of T-cell origin. One falls under the designation of primary cutaneous gamma-delta T-cell lymphomas (PGD-TCL) whereby there is dominant involvement of the fat defininng a panniculitic form of PGD-TCL. The neoplastic cells are of the gamma-delta subset and are either double negative for CD4 and CD8 and/or can express CD8. They often have an aggressive clinical course. The other form of panniculitic T-cell lymphoma falls under the designation of subcutaneous panniculitis-like T-cell lymphoma (SPTCL). It represents a subcutaneous lymphoma derived from CD8+ T cells of the alpha-beta subset and typically has an indolent course. These two forms of panniculitic T-cell lymphoma exhibit overlapping histologic features with lupus profundus (LP), a putative form of panniculitic T-cell dyscrasia. We present three cases of PGD-TCL of the fat in the setting of lupus erythematosus (LE) (two cases) and dermatomyositis (DM) (one case), respectively. There were concurrent features of LE and DM in their lymphoma biopsies in two cases while a prior biopsy in one was interpreted as LP. In this latter case, the LP diagnosis presaged the diagnosis of panniculitic PGD-TCL by three years. One patient diagnosed with panniculitic PGD-TCL had hemophagocytic syndrome after developing a lupus-like complex including certain supportive serologies such as antibodies to double-stranded DNA following initiation of statin therapy. The second patient presented with PGD-TCL and concomitant features of anti-nuclear matrix 2 (NXP2) DM. The third patient presented in 2003 with LP and overlying skin features of acute LE, initially responding to Plaquenil, and then four years later was diagnosed with PGD-TCL heralded by Plaquenil treatment resistance. Two of the patients died of their lymphoma. All biopsies showed a characteristic histopathology of PGD-TCL. In two cases, the PGD-TCL was associated with overlying LE-cutaneous findings; another case had skin changes of lymphocyte-rich DM. In two cases, the MXA stain was strikingly positive, the surrogate type I interferon marker that is typically upregulated in biopsies of LE and DM. There are eight prior reported cases describing SPTCL with concomitant cutaneous changes of LE. In six cases there was an established history of LE, including LP responding initially to Plaquenil, similar to one of our cases. In the context of SPTCL or panniculitic PGD-TCL, panniculitic T-cell lymphomas can be associated with concomitant clinical and histologic features of LE or DM, including an upregulated type I interferon signature. Identifying histologic features associated with either of these prototypic autoimmune conditions should not be considered exclusionary to diagnosing any panniculitic T-cell lymphoma. A clinical, histomorphologic, and pathophysiologic continuum exists with LP, SPTCL and panniculitic PGD-TCL.

The combined prevalence of classified rare rheumatic diseases is almost double that of ankylosing spondylitis

BACKGROUND

Rare diseases (RDs) affect less than 5/10,000 people in Europe and fewer than 200,000 individuals in the United States. In rheumatology, RDs are heterogeneous and lack systemic classification. Clinical courses involve a variety of diverse symptoms, and patients may be misdiagnosed and not receive appropriate treatment. The objective of this study was to identify and classify some of the most important RDs in rheumatology. We also attempted to determine their combined prevalence to more precisely define this area of rheumatology and increase awareness of RDs in healthcare systems. We conducted a comprehensive literature search and analyzed each disease for the specified criteria, such as clinical symptoms, treatment regimens, prognoses, and point prevalences. If no epidemiological data were available, we estimated the prevalence as 1/1,000,000. The total point prevalence for all RDs in rheumatology was estimated as the sum of the individually determined prevalences.

RESULTS

A total of 76 syndromes and diseases were identified, including vasculitis/vasculopathy (n = 15), arthritis/arthropathy (n = 11), autoinflammatory syndromes (n = 11), myositis (n = 9), bone disorders (n = 11), connective tissue diseases (n = 8), overgrowth syndromes (n = 3), and others (n = 8). Out of the 76 diseases, 61 (80%) are classified as chronic, with a remitting-relapsing course in 27 cases (35%) upon adequate treatment. Another 34 (45%) diseases were predominantly progressive and difficult to control. Corticosteroids are a therapeutic option in 49 (64%) syndromes. Mortality is variable and could not be determined precisely. Epidemiological studies and prevalence data were available for 33 syndromes and diseases. For an additional eight diseases, only incidence data were accessible. The summed prevalence of all RDs was 28.8/10,000.

CONCLUSIONS

RDs in rheumatology are frequently chronic, progressive, and present variable symptoms. Treatment options are often restricted to corticosteroids, presumably because of the scarcity of randomized controlled trials. The estimated combined prevalence is significant and almost double that of ankylosing spondylitis (18/10,000). Thus, healthcare systems should assign RDs similar importance as any other common disease in rheumatology.

Lipoatrophic panniculitis of children

Idiopathic lipoatrophic panniculitis of children is a rare disease of childhood, characterized by repeated attacks of tender subcutaneous nodules followed by the development of permanent lipoatrophy, often seen on the arms and legs, in association with fever, malaise, and other less common clinical manifestations such as abdominal pain or arthralgia. The pathogenesis is unknown, and autoimmune origins, chromosomal alterations, and other causes have been proposed. The nosology of this condition is confusing in the literature, and the precise diagnosis still relies on a combination of clinicopathologic and laboratory assessments. Methotrexate may be recommended to minimize disease progression and morbidity.

Analysis of the clinical characteristics of thirteen patients with Weber-Christian panniculitis

BACKGROUND

Weber-Christian disease (WCD) is an uncommon, idiopathic disease that is challenging to diagnose and has an unclear treatment protocol. We reviewed thirteen patients with WCD and analyzed their clinical characteristics. The purpose of this article was to improve the understanding of this rare disorder.

METHODS

Thirteen cases of WCD were analyzed retrospectively regarding their clinical manifestation, laboratory results, misdiagnoses, therapy, and outcome.

RESULTS

Of the thirteen patients diagnosed with WCD, the majority were female (male to female ratio, 2:11), with a mean patient age of 50.1 years. Subcutaneous nodules were the most commonly reported symptom, followed by fever, arthralgias/arthritis, and myalgia. The laboratory results were typically nonspecific. In total, 61.5% patients were misdiagnosed before pathology confirmed the diagnosis of WCD. Most patients were treated with corticosteroids and/or immunosuppressants. Two patients were treated surgically. While long-term remission was successfully achieved in some patients, others had recurrent symptoms.

CONCLUSION

WCD was predominantly observed in female patients in our cohort. Subcutaneous nodules and fever were the most common clinical characteristics. In addition, the patients' laboratory test results were nonspecific, which led to a high misdiagnosis rate. In this study population, corticosteroid and/or immunosuppressant treatments were efficacious therapeutic interventions for WCD.Key Points•Subcutaneous nodules and fever were the most common clinical characteristics in Weber-Christian panniculitis.•Misdiagnosis rate was higher in Weber-Christian panniculitis patient; tumors, bacterial infections and rheumatic diseases were the most common misdiagnoses.•Corticosteroid and/or immunosuppressant therapy was effective in most Weber-Christian panniculitis patients.

[Granulomatous reaction pattern of the skin : Interstitial granulomatous dermatitis - lymphoma - vasculitis]

A particular diagnostic situation in the classification of a granulomatous dermatitis results when no circumscribed granulomas but instead a diffuse interstitial histiocytic inflammatory infiltrate, a granulomatous vasculitis or a neoplastic lymphocytic infiltrate is found. Interstitial granulomatous dermatitis was originally described in patients with arthritis. Later, it was recognized that there are also associations with other usually immunological diseases. Differentiating between interstitial granulomatous dermatitis and the interstitial form of granuloma annulare, early morphea and variants of borreliosis or scleromyxedema as well as interstitial granulomatous drug reaction can be very difficult. In long-standing cutaneous granulomatous infiltrates, T‑cell lymphoma should be excluded. Occasionally only a small number of atypical lymphocytes can be found. The detection of a monoclonal T‑cell expansion is then particularly helpful. Only recently, a CD8-positive granulomatous cutaneous T‑cell lymphoma was described which occurred in patients with immunodeficiencies. A granulomatous vasculitis in the skin is extremely rare. According to the Chapel Hill classification from 2012, systemic granulomatous vasculitis is equated with giant cell arteritis. Extracutaneous large arteries are involved. On rare occasions, involvement of the temporal artery can result in skin necrosis. More commonly granulomatous infiltrates in combination with vasculitis can be observed, whereby various infectious diseases, sarcoidosis and nodular vasculitis should be considered. Granulomatosis with polyangiitis (formerly Wegener's granulomatosis), presents in the skin as leukocytoclastic vasculitis. Here granulomas are extremely rare.

Pfeifer-Weber-Christian disease and successful treatment with mycophenolate mofetil: a case report

Inflammatory conditions manifest with a broad spectrum of signs and symptoms. Panniculitis is such a condition affecting the subcutaneous fat and presents as tender erythematous nodules. It is also associated with a systemic response and has been described in the literature as early as in 1892 by Pfeifer and in the 1920s by Weber and Christian. We present an unusual case of a Caucasian man with recurrent febrile illness, systemic inflammatory response and renal dysfunction requiring acute high dependency care. The authors successfully treated him with an antiproliferative agent, mycophenolate mofetil, which resulted in preventing him from having further episodes.

[Weber-Christian's disease: a preleukemic disorder?]

La maladie de Weber-Christian ou panniculite idiopathique est une affection rare, caractérisée par une inflammation du tissu adipeux sous-cutané; il s'agit d'une entité pathologique non spécifique qui reste toujours un sujet de débat et dont l'évolution est imprévisible. Nous rapportons dans cet article le cas d'un nourrisson de sexe féminin de 9 mois, admise dans un tableau de sepsis précédé d'une symptomatologie respiratoire et suivi de l'apparition de nodosités sous cutanées érythémateuses, de petite taille, dures, sensibles, asymétriques et situées au niveau des bras et des membres inférieurs, la biopsie cutanée a montré une hypodermite lobulaire avec infiltration des polynucléaires neutrophiles. La maladie de Weber-Christian a été retenue après avoir éliminé les autres diagnostics différentiels. Notre patiente a été traitée par la prednisone avec une bonne évolution initiale. Durant le suivi et au cours de la dégression, le diagnostic d'une leucémie aigue lymphoblastique type B a été posé. Cette évolution atypique à notre connaissance n'a jamais été décrite dans la littérature. Nous allons discuter à travers ce cas les différentes situations similaires où un autre diagnostic a été fait après avoir pris en charge les malades comme ayant une panniculite lobulaire idiopathique, en concluant de la nécessité d'une enquête étiologique exhaustive et d'une surveillance prolongée afin de rechercher une éventuelle pathologie associée.

An Unusual Cause of Oligoarthritis and Erythema Nodosum: Idiopathic Granulomatous Mastitis

Idiopathic granulomatous mastitis (IGM) is an unusual benign inflammatory disease of breast. Breast cancer mimics IGM both radiologically and clinically. However, IGM is a benign disease and awareness of such an entity prevents unnecessary surgical procedures. Although its etiology is unknown, it may be an autoimmune disease. There are few patients reported in the literature presenting with reactive arthritis and/or erythema nodosum accompanying IGM of breast. Granulomatous mastitis should be considered as a possible underlying cause of arthritis and erythema nodosum. In this article, we report this interesting association of IGM as an underlying cause of arthritis and generalized erythema nodosum in a 32-year-old female patient. Comprehensive examination for granulomatous mastitis showed no apparent underlying cause. Indomethacin was beneficial in treatment of arthritis and erythema nodosum. Resistant IGM was responsive to colchicine treatment. Clinical management and therapeutic approach have been discussed in detail.

Recurrent panniculitis: Weber-Christian disease

Weber-Christian disease is characterized by recurrent inflammation in the fat layer of the skin. We report a boy, aged 2 years and 9 months, with Weber-Christian disease who presented with tender rounded swelling on the dorsum of both hands and chest wall with mild erythema in overlying skin associated with high grade continuous fever.

[Cutaneous panniculitis]

Panniculitis is an inflammation of the subcutaneous fat. Skin biopsy plays a critical role in the differential diagnosis of panniculitis. The most common approach to diagnosis relies on the differentiation between predominantly septal or lobular panniculitis, followed by the distinction between lesions with and without vasculitis. It is also very important to submit a part of the skin biopsy for microbiological analysis and for T-cell clonal expansion if T-cell lymphoma is suspected. Erythema nodosum, the most frequent septal panniculitis, has many causes and in its typical clinical presentation, does not require skin biopsy. In other panniculitis, diagnosis is based on the integration of the clinical and histological data, which renders a deep cutaneous biopsy necessary. Periarteritis nodosa, a septal panniculitis with vasculitis characterized by subcutaneous nodules and livedo racemosa, can be associated with systemic involvement. Nodular thrombophlebitis needs search for associated coagulopathy, Behçet's disease, periarteritis nodosa or Buerger's disease. Lobular panniculitis are classified according to the nature of cells present in the inflammatory infiltrate. If there is a lymphocytic infiltration, lupus panniculitis is difficult to differentiate from subcutaneous panniculitis-like T-cell lymphoma. If there are histiocytes, it can be a sarcoidosis, a cytophagic histiocytic panniculitis or, in newborn, a subcutaneous fat necrosis. Neutrophilic panniculitis needs careful clinic-pathologic correlation. Treatment of panniculitis can be challenging and is based on the histopathological findings. Frequently, the precise cause of panniculitis cannot be established from the outset, so it is important to follow-up patients and not hesitate to repeat the skin biopsy.

Multiple Mesenteric Panniculitis as a Complication of Sjögren's Syndrome Leading to Ileus

Mesenteric panniculitis (MP) is a benign fibroinflammatory process characterized by the presence of fat necrosis, chronic inflammation and fibrosis in the mesentery. Although various causal factors, such as malignancy, chronic inflammatory conditions and autoimmune processes, have been identified, the precise etiology remains unknown. We herein report a rare case of MP accompanying Sjögren's syndrome in which a mass lesion and intestinal stenosis were observed simultaneously. This condition led to ileus, which was effectively treated using prednisolone.

Weber-Christian disease with ileocolonic involvement successfully treated with infliximab

Weber-Christian disease (WCD) is an inflammatory disease whose main histological feature is lobular panniculitis of adipose tissue. The location of panniculitis determines the clinical presentation, being the subcutaneous adipose tissue the most frequent one, followed by liver, spleen, bone marrow and mesenteric adipose tissue. Systemic corticosteroids are first line treatment, but other options should be considered if systemic symptoms are observed or in case of refractory clinical situation. We report herein a case with WCD showing orbital, mesenteric and ileocolonic involvement, which required surgical treatment and also developed postoperative recurrence. Symptoms were resolved by administration of thalidomide and, afterwards, infliximab. To our knowledge, this is the first report of Weber-Christian disease with luminal ileocolonic involvement, treated with infliximab.

Update on management of connective tissue panniculitides

In connective tissue diseases, panniculitis can be the sole manifestation or can occur along with the underlying disease process. The best described forms of connective tissue panniculitis are lupus erythematosus panniculitis and lupus profundus, panniculitis associated with dermatomyositis, and morphea- and scleroderma-associated panniculitis. These processes cause significant morbidity, such as deep atrophic scars, cosmetic disfigurement, and psychiatric sequelae. Because the inflammation is located in the subcutaneous adipose layer, topical therapies may not penetrate enough to be effective, and systemic agents are required. Despite the large number of reported cases and therapies, recommendations for treatment are based largely on case series and expert opinion due to a lack of controlled therapeutic trials. All treatments are off-label in the United States. The lack of validated clinical outcome measures makes systematic and controlled studies difficult. Nonetheless, further investigation into the most effective therapies for these conditions is needed.

[Lipoatrophic panniculitis in adults: treatment with hydroxychloroquine]

BACKGROUND

Lipoatrophic panniculitis is generally considered to be a rare disease affecting children. We report a case involving this condition in an adult patient presenting with striking clinical features and responding to hydroxychloroquine therapy. We discuss the nosological relationship between lipoatrophic panniculitis and connective tissue panniculitis.

PATIENTS AND METHODS

A 62-year-old woman was referred to our institution with a six-month history of painful erythematous nodules and plaques on the calves, thighs, buttocks, breasts, abdomen and arms. With each outbreak of new lesions, she felt unwell and experienced fever, chills and sweating. After a few weeks, the lesions progressed circumferentially and led to large areas of subcutaneous atrophy showing a central depression covered with a yellowish, supple skin and surrounded by an annular, infiltrated, erythematous and tender inflammatory margin. Deep subcutaneous biopsy specimens showed typical features of lobular and septal lipophagic panniculitis, with a dense inflammatory infiltrate composed of large histiocytes, multinucleated giant cells and few neutrophils, without vasculitis. The patient was started on hydroxychloroquine 400 mg daily. Three weeks later, her pain and tenderness had completely resolved and the inflammatory margin of the lesions had clearly regressed.

DISCUSSION

This unique condition, with distinctive clinical and histological features, is similar to cases described under the term "lipophagic panniculitis", seen mostly in children, but also "connective tissue panniculitis". Their clinical resemblance and response to hydroxychloroquine therapy leads us to think that these two entities, previously subsumed under the eponym of Weber-Christian disease or Rothman-Makai syndrome, are closely related.

CONCLUSION

Dermatologists and dermatopathologists should be made aware of this unusual entity, and of the fact that it can arise in adult patients, so that they may make an early diagnosis and thus prevent the unsightly consequences of lipoatrophy.

Cytophagic histiocytic panniculitis with haemophagocytosis in a patient with familial multiple lipomatosis and review of the literature

We report a patient with the extremely rare familial multiple lipomatosis syndrome, who developed the uncommon autoimmune disease cytophagic histiocytic panniculitis, manifested as inflammation of preexisting lipomas. Despite his initial critical condition and unsuccessful treatment with steroids, he responded to cyclosporin and remains well 15 years after diagnosis. In contrast with most previous reports, our patient stays dependent on cyclosporin; repeated attempts of discontinuing or substituting treatment were quickly followed by relapse. Haemophagocytic panniculitis is considered as a T-cell disorder, but its exact pathophysiological mechanism has not been clarified. Differential diagnosis of cytophagic histiocytic panniculitis mainly includes malignant histiocytosis, subcutaneous panniculitis-like T-cell lymphoma (SPTCL) and lupus erythematosus panniculitis (lupus profundus). We discuss the main clinical features, diagnostic challenges and treatment issues of this usually benign, but at times life-threatening autoimmune condition.

A case of Weber-Christian disease with later development of rheumatoid arthritis

Weber-Christian disease (WCD) is a syndrome characterized by recurrent subcutaneous nodules, fever, occasional lipoatrophy, fatigue, arthralgia, and myalgia. We report a case of WCD associated with rheumatoid arthritis. A 65-year-old woman consulted our outpatient clinic because of bilateral hand swelling. The patient had presented with fever and subcutaneous nodules in her trunk and upper and lower extremities in 1983. At that time, the dermatology department diagnosed this patient as having WCD after biopsy of the nodules demonstrated lobular panniculitis. She has been treated with corticosteroid (5-15 mg/day) since then. The patient continued to have recurrent episodes of transient inflammatory arthritis in the small joints of the fingers and fever, and was initially assessed at our institution in October 2007. Finally, in November 2007, she was diagnosed as having both WCD and rheumatoid arthritis (RA) and treated with corticosteroid (5 mg/day) and methotrexate (MTX) (7.5 mg/week). Thereafter, her clinical symptoms gradually improved. This is the second case of WCD showing the subsequent development of RA, successfully treated with MTX, in the English literature. This case may provide clinical insight into WCD and RA.

Annular lipoatrophic panniculitis of the ankles

We report a girl with lipophagic lobular panniculitis of unknown origin located on her ankles leading to circumferential fat atrophy of the ankles, a condition usually referred to as "annular lipoatrophy of the ankles." According to our patient's features and five additional cases reported so far, we conclude that this condition is actually an end-stage manifestation of an idiopathic lobular panniculitis of children localized to the lower part of the lower limbs. An association with some autoimmune manifestations is highlighted.

Lobular panniculitis with small vessel vasculitis associated with ulcerative colitis

We report a rare case of lobular panniculitis with small vessel vasculitis, presenting with fever, cutaneous lesions, and systemic manifestations involving the visceral fat and associated with ulcerative colitis. The patient was treated with cyclophosphamide and prednisolone, which successfully cured the systemic disease, with resolution of the inflammatory infiltrates.

Diffuse lower limb lipoatrophy

Lipoatrophic panniculitis is the term used to describe those panniculitides in which atrophy of the subcutaneous fat is the main residual lesion. They can be classified as primary or secondary. Primary lipoatrophic panniculitis is idiopathic, whereas secondary lipoatrophic panniculitides include those because of infection, malignancy, pancreatic disorders or connective tissue diseases. Usually, these entities are characterized by the appearance of tender, erythematous nodules or plaques that resolve leaving one or several localized areas with loss of subcutaneous fat. We report a 76-year-old female who developed diffuse and symmetric lipoatrophy of lower limbs after an extensive inflammatory process affecting both extremities from thighs to ankles. Histopathologic assessment revealed a lobular panniculitis with a lymphohistiocytic infiltrate, foamy macrophages and lipophagic granuloma formation. The most striking feature in our patient was the clinical presentation as a symmetrical diffuse inflammatory process resulting in lipoatrophy of the lower limbs.

A patient with Pfeifer-Weber-Christian disease--successful therapy with cyclosporin A: case report

BACKGROUND

Pfeifer-Weber-Christian disease (PWCD) is a rare inflammatory disorder of the subcutaneous fatty tissue. The diagnosis and therapy of this rare type of panniculitis is still controversial and will be discussed in this article.

CASE PRESENTATION

We here report the rare case of a 64-year old male patient, with PWCD. The patient suffered from rheumatoid arthritis for several years, but then developed relapsing fever and recently occurring painful subcutaneous nodules predominantly at the inner part of his left upper limb with no signs of synovitis. Finally, a biopsy from one of the nodules revealed lobular panniculitis with mixed cell infiltrate, which was conformable only with PWCD, after excluding several differential diagnoses. In our patient PWCD developed despite immunosuppressive therapy with steroids and different disease modifying drugs, which the patient received to treat his underlying rheumatoid arthritis. However, when DMARD therapy was switched to Ciclosporin A the patient's symptoms resolved.

CONCLUSION

Our observation supports the hypothesis that T cells are involved in the pathogenesis of PWCD. Thus, T cell modifying drugs should be primarily used to treat patients with this rare disorder.

Lipoatrophic connective tissue panniculitis

Many causes of what was formerly called Weber-Christian and Rothmann-Makai diseases are being clarified as specific forms of panniculitis. Among them, an autoimmune process involving the subcutaneous fat without criteria for another defined disorder coined "connective tissue panniculitis" by Winckelman et al in 1980 has been described. We describe this disease in a 4-year-old boy who presented with multiple subcutaneous inflammatory nodules that extended in an annular fashion, resolved leaving lipoatrophy, with recurrence 8 years later. The histologic findings were consistent with a granulomatous lipophagic panniculitis. We review previous reports and emphasize the limited therapeutic options, chronic evolution, severe esthetic sequelae and possible association with other autoimmune disorders of this uncommon condition.

Isotretinoin is not associated with inflammatory bowel disease: a population-based case-control study

OBJECTIVES

There is anecdotal evidence that isotretinoin use is associated with development of colitis. We aimed at determining whether there is an association between isotretinoin use and development of inflammatory bowel disease (IBD).

METHODS

The population-based University of Manitoba IBD Epidemiology Database and a control group matched by age, sex, and geographical residence were linked to the provincial prescription drug registry, a registry that was initiated in 1995. The number of users and duration of isotretinoin use were identified in both IBD cases and controls.

RESULTS

We found that 1.2% of IBD cases used isotretinoin before IBD diagnosis, which was statistically similar to controls (1.1% users). This was also similar to the number of IBD patients who used isotretinoin after a diagnosis of IBD (1.1%). There was no difference between isotretinoin use before Crohn's disease compared with its use before ulcerative colitis.

CONCLUSIONS

Patients with IBD were no more likely to have used isotretinoin before diagnosis than were sex-, age-, and geography-matched controls. Although there may be anecdotes of isotretinoin causing acute colitis, our data suggest that isotretinoin is not likely to cause chronic IBD.

Panniculitis in children

The panniculitides include a group of disorders of varied etiology that manifest as inflamed nodules in the subcutaneous tissue. They are rarely seen in infants and children. The panniculitides of the newborn represent a unique response of the infant's fat to different injuries, and are a specific type of panniculitis that is only seen in neonates and very young infants. These specific panniculitides of children include subcutaneous fat of the newborn, poststeroid panniculitis, sclerema neonatorum, and cold panniculitis. This article reviews in detail the specific types of panniculitis of the newborn and discusses the pediatric aspects of the panniculitis that is often seen in adults.

Successful treatment of idiopathic febrile panniculitis (Weber-Christian disease) with thalidomide in a patient having failed multiple other medical therapies

The authors describe a case of idiopathic nodular panniculitis (Weber-Christian disease) with recurrent febrile episodes resistant to glucocorticosteroids and methotrexate (MTX) in various combinations with hydroxychloroquine, azathioprine, cyclosporine, colchicine, and doxycycline. Thalidomide at 100 mg/day has induced a remission for 3 years.

What is That Nodule?

The evaluation of patients with subcutaneous nodules remains a diagnostic challenge. The presence of nodules can be a clue to an underlying systemic disease; however, the varied presentations of nodules and numerous disease associations make the assessment of patients with nodules far from simple. With further investigation into the appearance, location, and symptoms associated with nodules, the clinical significance of these lesions can become clearer and aid in logical diagnostic evaluation. We have reviewed the causes of nodules with emphasis on those associated with rheumatic disease and provide guidelines for nodule evaluation to better characterize disease association and lead to directed diagnostic assessment.

A case of Weber-Christian disease with collapsing glomerulopathy

We report a case of Weber-Christian disease confirmed by skin biopsy in a patient who presented with collapsing glomerulopathy and lipophagic interstitial nephritis. On renal biopsy, glomerular visceral epithelial cells, tubular cells, and interstitial macrophages were loaded with inclusions that were morphologically consistent with oxidized lipoproteins, suggesting that lipids derived from the panniculitis may have an etiopathogenic role.

The protean spectrum of non-Hodgkin lymphomas with prominent involvement of subcutaneous fat

BACKGROUND

Subcutaneous T-cell lymphoma (STCL) represents a controversial entity and a confused concept in the field of cutaneous T-cell lymphomas (CTCLs). Recently, alpha/beta+/CD8+ STCL has been recognized by the new World Health Organization (WHO)-European Organization for Research and Treatment of Cancer (EORTC) classification of primary cutaneous lymphomas as a distinct entity in the group of CTCLs.

OBSERVATIONS

We reviewed a series of 53 biopsies from 26 patients (F : M = 19:7; median age: 48; range 18-87) of cutaneous B- and T-cell lymphomas characterized by prominent involvement of the subcutaneous tissue. We could classify our cases according to the following seven categories--(i) STCL: n = 16; (ii) extranodal NK/T-cell lymphoma, nasal type: n = 2; (iii) cutaneous gamma/delta T-cell lymphoma: n = 2; (iv) anaplastic CD30+ large T-cell lymphoma: n = 1; (v) diffuse large B-cell lymphoma, secondary cutaneous: n = 3; (vi) lymphoplasmacytic lymphoma, secondary cutaneous: n = 1; (vii) specific cutaneous manifestations of myelogenous leukemia: n = 1.

CONCLUSIONS

We demonstrated the protean nature of lymphomas with prominent involvement of the subcutaneous fat tissues. The term STCL should be restricted to a homogeneous group of cases characterized morphologically by an exclusive involvement of subcutaneous tissues, immunohistochemically by a T-cytotoxic alpha/beta phenotype, and biologically by a relatively good prognosis.

Histopathologic spectrum of erythema nodosum

Erythema nodosum (EN) is the most common panniculitis and histologically represents the prototype of a septal panniculitis. However, the histologic findings can be quite variable. We describe four patients with EN who each underwent two consecutive biopsies. In each case, the first biopsy showed histopathologic features that fall outside the usual spectrum of disease. Two cases showed predominantly neutrophilic infiltrates with focal suppuration as well as vasculitis of medium-sized arteries. The areas of suppuration were more extensive in the first case prompting special stains for microorganisms that were all negative. The third case demonstrated a lobular panniculitis with a predominantly lymphohistiocytic infiltrate. Special stains were negative in this case as well. The fourth case revealed vasculitis of a medium sized artery, small vessel vasculitis, and a mixed septal and lobular panniculitis with a polyclonal population of atypical lymphocytes. In all patients, the clinical course and the subsequent biopsy were classic for EN. We conclude that lobular neutrophilic panniculitis with suppuration, small vessel vasculitis, and even medium vessel arteritis may rarely occur in EN. There are few clues in these unusual cases that allow for a specific diagnosis from the start, and often, a second biopsy is required.

Adipocyte death defines macrophage localization and function in adipose tissue of obese mice and humans

Macrophage infiltration of white adipose tissue (WAT) is implicated in the metabolic complications of obesity. The precipitating event(s) and function(s) of macrophage infiltration into WAT are unknown. We demonstrate that >90% of all macrophages in WAT of obese mice and humans are localized to dead adipocytes, where they fuse to form syncytia that sequester and scavenge the residual "free" adipocyte lipid droplet and ultimately form multinucleate giant cells, a hallmark of chronic inflammation. Adipocyte death increases in obese (db/db) mice (30-fold) and humans and exhibits ultrastructural features of necrosis (but not apoptosis). These observations identify necrotic-like adipocyte death as a pathologic hallmark of obesity and suggest that scavenging of adipocyte debris is an important function of WAT macrophages in obese individuals. The frequency of adipocyte death is positively correlated with increased adipocyte size in obese mice and humans and in hormone-sensitive lipase-deficient (HSL-/-) mice, a model of adipocyte hypertrophy without increased adipose mass. WAT of HSL-/- mice exhibited a 15-fold increase in necrotic-like adipocyte death and formation of macrophage syncytia, coincident with increased tumor necrosis factor-alpha gene expression. These results provide a novel framework for understanding macrophage recruitment, function, and persistence in WAT of obese individuals.