Panniculitis: recent developments and observations

A Case of Erythema Nodosum in a 20-Year-Old Female During the Postpartum Period

Erythema nodosum (EN) is the most common form of panniculitis and occurs in about one in 100,000 people. EN typically presents as an eruption of tender, erythematous nodules on the anterior aspect of the legs, although the face, trunk, and arms can also be involved. While the majority of cases are idiopathic, a subset of cases occurs in association with various triggers, including infections, medications, tumors, and autoimmune diseases. Rarely can EN develop in relation to pregnancy, which is thought to provide a physiologic background that favors its development. While pregnancy has been associated with EN in a minority of cases, currently, there is a limited amount of data suggesting that EN can develop in the late postpartum period. Herein, we present a case of a 20-year-old female with a six-week history of painful lesions on her lower extremities. A physical exam revealed multiple tender, erythematous nodules on the anterior aspect of the lower extremities, spanning from the knees to the toes. Laboratory workup showed no other identified triggers of EN in our patient besides pregnancy. Management of EN in our patient involved a low dose, six-day course of prednisone (initial dose of 15 mg/day) and ibuprofen for one week, leading to symptomatic improvement. Our case emphasizes the possibility of EN presenting in the late postpartum period. This case underscores the importance of considering EN in the differential diagnoses for women presenting with compatible lesions postpartum.

Breast panniculitis with liquefactive fat necrosis: A case report

Panniculitis is a group of heterogeneous disorders characterized by inflammation of the subcutaneous adipose tissue. Panniculitis of breast tissue as the initial manifestation has rarely been reported and is often misdiagnosed. Breast panniculitis may cause substantial morbidity and early diagnosis and treatment are important for the prognosis of the disease. The present study has reported a case of panniculitis with inflammation of the mammary glands as the initial presentation and provided a detailed description of ultrasonography, X-ray, computed tomography, magnetic resonance imaging and other imaging features of breast panniculitis. The treatment and follow-up were also described. Following treatment with systemic corticosteroids combined with methotrexate and thalidomide for 2 months, the breast appeared to be normal without scar formation. The present case report provides a good reference for the future diagnosis and treatment of breast panniculitis.

Panniculitis: A summary

The diagnosis of panniculitis is felt to be a confusing topic by some pathologists. This summarical article presents inflammatory diseases of the subcutis in a systematic fashion, based on whether they are centered on fibrovascular septa or the adipose lobules, and whether morphologic vasculitis is present or not. Septocentric, non-vasculitis disorders include erythema nodosum, panniculitis that follows the use of "biological" therapeutic agents, lipodermatosclerosis, post-irradiation panniculitis, morphea profunda, and necrobiosis lipodica profunda. Polyarteritis nodosa and Behçet's disease are the conditions that are based in the subcutaneous septa with vasculitis. Predominantly-lobular panniculitides with no vasculitis include pancreatogenic panniculitis, the panniculitis of alpha-1-antitrypsin deficiency, panniculitis associated with lupus erythematosus and dermatomyositis, subcutaneous Sweet syndrome, eosinophilic panniculitis, factitial panniculitis, cold panniculitis, panniculitis following injections of corticosteroids, lipomembranous (ischemic) panniculitis; sclerema neonatorum and subcutaneous fat necrosis of the newborn, and Rosai-Dorfman disease of the subcutis. Erythema induratum and infectious panniculitis are vasculitic and lobulocentric conditions. This article reviews the histological features of these diseases.

Dermal Changes in the Lower Leg Skin of Patients With Venous Hypertension

Patients with chronic venous disease may develop characteristic changes in the skin of the lower limb known as lipodermatosclerosis (LDS). The affected skin becomes indurated and pigmented and often ulcerates. The degree of induration associated with LDS correlates directly with ulcer formation and leads to a subsequent delayed rate of healing. However, there is limited information regarding the cellular and molecular events that lead from venous dysfunction to LDS development. This article reviews the current knowledge of the clinical progression of chronic venous disease, summarizing the histological findings from these authors’ laboratory and other studies on LDS, and offers possible mechanisms to explain the fibrotic changes associated with this condition.

Neutrophilic panniculitis: algorithmic approach to a heterogeneous group of disorders

CONTEXT

Neutrophilic panniculitis encompasses an etiologically and morphologically heterogeneous group of disorders. Correct histopathologic diagnosis is important in identifying certain systemic diseases and guiding appropriate treatment.

OBJECTIVE

To review the clinical and histopathologic features of different types of neutrophilic panniculitis, and to provide a diagnostic algorithm for these disorders.

DATA SOURCES

A review of the literature with emphasis on the distinguishing features of different entities was performed.

CONCLUSIONS

Evaluation for neutrophilic panniculitis entails paying close attention to the pattern of inflammation, the type of fat necrosis present, any evidence of vascular damage, and other relevant histopathologic features. An algorithmic approach integrating all histopathologic, clinical, and laboratory findings is required for correct diagnosis.

Histoplasmosis and subcutaneous nodules in a kidney transplant recipient: erythema nodosum versus fungal panniculitis

Erythema nodosum (EN)-like lesions are a rare occurrence after solid organ transplantation. Differential diagnosis includes infective panniculitis, which can be a feature of progressive disseminated histoplasmosis (PDH), an uncommon but severe form affecting primarily immunocompromised hosts. We report on a fatal case of PDH, which presented as fungal panniculitis masquerading as EN in a renal allograft recipient 25 years after transplantation. We discuss the clinical, histopathological, and microbiological characteristics of this rare complication, with focus on its distinction from EN. This case emphasizes the central role of biopsy in transplant recipients presenting with cutaneous lesions, and the importance of clinicopathologic correlation and complementary microbiological investigations.

Anatomy and histology of normal subcutaneous fat, necrosis of adipocytes, and classification of the panniculitides

The panniculitides comprise a group of heterogeneous inflammatory diseases that involve the subcutaneous fat. Histopathologic study is required for the specific diagnosis of these disorders, because different panniculitides usually show the same clinical appearance, which consists of erythematous nodules on the lower extremities. The histopathologic study of panniculitis is difficult, however, because of an inadequate clinicopathologic correlation and the changing evolutive nature of the lesions. Some cutaneous lymphomas may simulate panniculitis, both from clinical and histopathologic points of view, and for that reason are included in this article despite the fact that they are not inflammatory processes but authentic lymphocytic neoplasms involving subcutaneous tissue.

Nephrogenic systemic fibrosis with septal panniculitis mimicking erythema nodosum

Nephrogenic systemic fibrosis/nephrogenic fibrosing dermopathy is an idiopathic fibrosing disorder recently described in patients with renal disease. The typical histology in nephrogenic systemic fibrosis consists of haphazardly arranged dermal collagen bundles with clefting, collagenous change which extends into the subcutaneous septa, mucin deposition, fibroblast proliferation, and increased elastic fibers with minimal inflammation. We present a 65-year-old female with classic clinical features whose biopsy demonstrated unique histologic features of septal pannicilitis with lymphocytic aggregates and Miescher's radial granulomas mimicking erythema nodosum.

Normal subcutaneous fat, necrosis of adipocytes and classification of the panniculitides

The panniculitides represent a group of heterogeneous inflammatory diseases that involve the subcutaneous fat. The specific diagnosis of these diseases requires histopathologic study because different panniculitides usually show the same clinical appearance, which consists of erythematous nodules on the lower extremities. However, the histopathologic study of panniculitis is difficult because of an inadequate clinicopathologic correlation and the changing evolutive nature of the lesions. In addition, large scalpel incisional biopsies are required. From histopathologic point of view, all panniculitides are somewhat mixed because the inflammatory infiltrate involves both the septa and lobules. However, nearly always the differential diagnosis between a mostly septal and a mostly lobular panniculitis is straightforward at scanning magnification on the basis of the structures more intensely involved by the inflammatory infiltrate. Mostly septal panniculitides with vasculitis are actually more vasculitis than panniculitis and include superficial thrombophlebitis and cutaneous polyarteritis nodosa. Mostly septal panniculitides with no vasculitis include erythema nodosum, necrobiosis lipoidica, deep morphea, subcutaneous granuloma annulare, rheumatoid nodule, and necrobiotic xanthogranuloma. Mostly lobular panniculitis with vasculitis is only represented by erythema induratum of Bazin. In contrast, mostly lobular panniculitides without vasculitis comprise a large series of disparate disorders, including sclerosing panniculitis, calciphylaxis, sclerema neonatorum, subcutaneous fat necrosis of the newborn, poststeroid panniculitis, lupus erythematosus profundus, pancreatic panniculitis, alpha(1)-antitrypsin deficiency panniculitis, subcutaneous Sweet syndrome, infective panniculitis, factitial panniculitis, lipodystrophy, traumatic panniculitis, subcutaneous sarcoidosis, and sclerosing postirradiation panniculitis. Finally, some cutaneous lymphomas may simulate panniculitis, both from clinical and histopathologic points of view and, for that reason, they will be included in this review, although they are not inflammatory processes, but authentic lymphocytic neoplasms involving subcutaneous tissue.

Erythema Nodosum

Erythema nodosum is the most frequent clinicopathologic variant of panniculitis. The process is a cutaneous reaction that may be associated with a wide variety of disorders, including infections, sarcoidosis, rheumatologic diseases, inflammatory bowel diseases, medications, autoimmune disorders, pregnancy, and malignancies. Erythema nodosum typically manifest by the sudden onset of symmetrical, tender, erythematous, warm nodules and raised plaques usually located on the lower limbs. Often the lesions are bilaterally distributed. At first, the nodules show a bright red color, but within a few days they become livid red or purplish and, finally, they exhibit a yellow or greenish appearance, taking on the look of a deep bruise. Ulceration is never seen, and the nodules heal without atrophy or scarring. Histopathologically, erythema nodosum is the stereotypical example of a mostly septal panniculitis with no vasculitis. The septa of subcutaneous fat are always thickened and variously infiltrated by inflammatory cells that extend to the periseptal areas of the fat lobules. The composition of the inflammatory infiltrate in the septa varies with age of the lesion. In early lesions edema, hemorrhage, and neutrophils are responsible for the septal thickening, whereas fibrosis, periseptal granulation tissue, lymphocytes, and multinucleated giant cells are the main findings in late stage lesions of erythema nodosum. A histopathologic hallmark of erythema nodosum is the presence of the so-called Miescher's radial granulomas, which consist of small, well-defined nodular aggregations of small histiocytes arranged radially around a central cleft of variable shape. Treatment of erythema nodosum should be directed to the underlying associated condition, if identified. Usually, nodules of erythema nodosum regress spontaneously within a few weeks, and bed rest is often sufficient treatment. Aspirin, nonsteroidal antiinflammatory drugs, such as oxyphenbutazone, indomethacin or naproxen, and potassium iodide may be helpful drugs to enhance analgesia and resolution. Systemic corticosteroids are rarely indicated in erythema nodosum and before these drugs are administered an underlying infection should be ruled out.

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.

An Unusual Case of Calciphylaxis

Background:

Cutaneous calciphylaxis is a rare disorder that occurs most frequently in patients with end-stage renal disease (ESRD), those on hemodialysis, and renal transplant recipients. It is frequently associated with hyperparathyroidism and a markedly elevated calcium–phosphate product, and it carries a high mortality rate. The usual clinical presentation is of painful, stellate necrosis of the thighs or buttocks, often in the setting of livedo reticularis. Death usually results from septicemia.

Objective:

This report documents an unusual case of recurrent, self-limiting calciphylaxis in the setting of a patient with ESRD and discusses the clinical and pathologic features of this potentially very fatal disorder.

Methods and Remits:

A 52-year-old woman presented with a greater than one-year history of relapsing and remitting, exquisitely painful, necrotic, numular plaques on the abdomen, breast, and arm. This patient had a markedly elevated calcium–phosphate product and parathyroid hormone level. The diagnosis of calciphylaxis was made by wedge biopsy of the most recent plaque, revealing calcification of medium-sized subcutaneous vessels and lobular capillaries with associated epidermal necrosis.

Conclusions:

This case demonstrates an unusual clinical variant of calciphylaxis that presented without the characteristic stellate necrosis or livedo reticularis that normally marks this condition and spontaneous resolution without incurring septicemia. Regardless of morphology, calciphylaxis should be considered in the differential diagnosis of painful, necrotic lesions occurring in the setting of ESRD.

Red fingers syndrome and recurrent panniculitis in a patient with chronic hepatitis C

Cases of red fingers syndrome and nodular vasculitis in patients with hepatitis C have rarely been described. Both red fingers syndrome and nodular vasculitis are characterized by microscopic vasculitis, and it has been hypothesized that hepatitis C plays a role in the pathogenesis of cutaneous disorders such as vasculitis, especially in cryoglobulinaemic vasculitis. We describe the case of a 75-year-old woman diagnosed with chronic hepatitis C who presented with nodular lesions on her right thigh and red fingers syndrome. A skin biopsy taken from a nodule showed infiltration of the vessel walls by mononuclear cells and septal and lobular panniculitis. The diagnosis of nodular vasculitis was established. In our opinion, red fingers syndrome and nodular vasculitis might be related to a vascular reaction of immune-mediated mechanisms induced by hepatitis C.

Sclerosing lipogranuloma of the orbit after periocular steroid injection

PURPOSE

To report the clinical and histopathologic findings of a large sclerosing lipogranuloma of the orbit arising after a sub-Tenon's corticosteroid injection.

DESIGN

Interventional case report and review of the literature.

METHODS

A complete ocular and systemic evaluation was performed on a 81-year-old patient, who developed a large orbital mass subsequent to a periocular corticosteroid injection producing proptosis, ptosis, and ocular motility impairment. The lesion was biopsied and submitted for histopathologic analysis.

MAIN OUTCOME MEASURES

Orbital, computed tomography, and histopathologic findings.

RESULTS

Histopathologic examination revealed lipogranulomatous inflammation. Specifically, this type of reaction was consistent with a diagnosis of sclerosing lipogranuloma.

CONCLUSIONS

It is extremely rare to find a large granulomatous orbital lesion arising subsequent to a periocular corticosteroid injection. Only one case has been reported in the English-language literature to date. It is important to include this type of lesion in the differential diagnosis of an orbital mass seen after the injection of periocular corticosteroids.

Panniculitis

The classification of inflammatory disorders of the subcutaneous tissue has mystified dermatologists for decades. Overlapping clinical and histologic features, and a lack of specific treatments have added to the confusion. This article initially classifies the various panniculititides by their primary histopathologic pattern: (1) septal panniculitis without vasculitis, (2) septal panniculitis with vasculitis, (3) lobular panniculitis without vasculitis, and (4) lobular panniculitis with vasculitis. Subsequently, we describe the key clinical findings in the most important forms of panniculitis. We begin with the most common form of panniculitis, erythema nodosum. Indeed, in many patients suspected of having panniculitis, a worthwhile question to consider initially might be, "Is this, or is this not, erythema nodosum?" before engaging in an elaborate (and expensive) exercise in differential diagnosis.

Panniculitis. Part I. Mostly septal panniculitis

The panniculitides represent a group of heterogeneous inflammatory diseases that involve the subcutaneous fat. The specific diagnosis of these diseases requires histopathologic study because different panniculitides usually show the same clinical appearance, which consists of subcutaneous erythematous nodules on the lower extremities. However, the histopathologic study of panniculitis is difficult because of an inadequate clinicopathologic correlation, and the changing evolutionary nature of the lesions means that biopsy specimens are often taken from late-stage lesions, which results in nonspecific histopathologic findings. In addition, large-scalpel incisional biopsies are required. However, we believe that by obtaining appropriate biopsy specimens and with adequate clinicopathologic correlation, a specific diagnosis may be rendered in most cases of panniculitis. It must be accepted that all panniculitides are somewhat mixed because the inflammatory infiltrate involves both the septa and lobules; however, in general the differential diagnosis between a mostly septal and a mostly lobular panniculitis is straightforward at scanning magnification. Mostly septal panniculitides with vasculitis include leukocytoclastic vasculitis involving the small blood vessels of the septa; superficial thrombophlebitis resulting from inflammation and subsequent thrombosis of large veins of the septa; and cutaneous polyarteritis nodosa, which is a vasculitis involving arteries and arterioles of the septa of subcutaneous fat with few or no systemic manifestations. Often septal panniculitides with no vasculitis are the consequence of dermal inflammatory processes extending to the subcutaneous fat, such as necrobiosis lipoidica, scleroderma, subcutaneous granuloma annulare, rheumatoid nodule, and necrobiotic xanthogranuloma. However, in other cases, the inflammatory process is primarily located in the fibrous septa of the subcutis with or without involvement of the overlying dermis. The most frequently seen septal panniculitis is erythema nodosum, which, in fully developed lesions, is characterized histopathologically by Miescher's radial granulomas in the septa.

Histopathologic features of erythema nodosum--like lesions in Behçet disease: a comparison with erythema nodosum focusing on the role of vasculitis

Many patients with Behçet disease (BD) develop lesions that clinically resemble those of erythema nodosum (EN) but differ from that condition with regard to their microscopic features. We examined 11 sections of EN-like lesions in BD and compared them with 9 sections of classic EN using routine histopathology and immunohistochemistry so as to form a comprehensive picture of the pathologic findings in BD and to determine the role of vasculitis in the formation of lesions. Erythema nodosum-like lesions of BD are characterized by panniculitis, usually lobular or mixed septal and lobular in pattern, with variable numbers of neutrophils, lymphocytes, and histiocytes as well as variable numbers of necrotic adipocytes. Vasculitis was noted in most EN-like lesions in BD. Scattered vessels showing lymphocytic vasculitis were evident in 6 sections, and foci of leukocytoclastic vasculitis were obvious in 4 sections, sometimes with phlebitis or arteriolitis. In specimens with classic EN, we did not observe vasculitis. Only the percentages of CD3+ lymphocytes and chloroacetate esterase-positive neutrophils in the infiltrating cells showed statistically significant differences (P < 0.05) between EN-like lesions in BD and EN through immunohistochemical and enzyme cytochemical studies. Because vasculitis in the EN-like lesions in BD was extensive and not limited to areas of severe inflammation, we believe that it is primary vasculitis. We suggest that vasculitis is an important pathologic event in EN-like lesions in BD but cannot determine the extent to which other pathologic changes such as septal or lobular panniculitis, fat necrosis, neutrophilic infiltration, or microabscess formation are secondary features.

Calcified subcutaneous arterioles with infarcts of the subcutis and skin ("calciphylaxis") in chronic renal failure

Patients with chronic renal failure (CRF) are at increased risk for pathological calcifications because of increased serum calcium-phosphorus products. A minority, including those undergoing dialysis, develop a syndrome of deep skin ulcerations in association with calcification of subcutaneous arterioles. The body distribution of the skin lesions may be proximal (central), distal (peripheral), or both. Since 1968, this syndrome has been called "calciphylaxis" in the belief that it is the human analogue of Selye's experimental models of tissue calcification. Our review emphasizes that this syndrome comprises two separate processes not found in calciphylaxis: calcification of subcutaneous arterioles and infarctions of subcutaneous adipose tissue (panniculus adiposus) and skin. The infarctions are acute and clinically dramatic, whereas the calcific arteriolopathy is preexistent, having developed slowly, sometimes over years, and silently. Separating these two processes facilitates analyses of pathogenetic factors, such as those that target subcutaneous arterioles for calcification and those that interfere with blood flow through the calcified arterioles, sufficient in some patients to cause the infarctions, and of why obesity in CRF is a syndrome risk factor. This approach further helps to provide a much needed standardized definition of the syndrome, thereby facilitating comparisons of the results of such treatments as parathyroidectomy, anticoagulants, and phosphate binders. Finally, the separation shows why the application of such terms as calciphylaxis and calcifying panniculitis to this syndrome is inappropriate.

Cutaneous calciphylaxis. An underrecognized clinicopathologic entity

Calciphylaxis (CPX), an uncommon syndrome characterized, in part, by progressive cutaneous vascular calcification, is seen principally in the setting of renal failure-associated hyperparathyroidism and is difficult to distinguish histologically from other microvasculopathies. We assessed histologic specimens from 13 cases of clinicopathologically classic CPX of the skin and reviewed documented histologic findings in the literature. Our series included 7 "early" and 6 "late" lesions (absence or presence of tissue necrosis, respectively). Histologically, early lesions were subtle and almost inapparent microscopically. Late lesions were easier to recognize because of obvious epidermal ulceration, dermal necrosis, and easily seen mural vascular calcification. The most common finding in both groups was acute and chronic calcifying septal panniculitis. Endovascular fibroblastic proliferation was more common in advanced lesions. Necrosis of dermal collagen was identified in only a few early lesions. Frank luminal vascular thrombosis was infrequent in both groups. The cited histologic findings largely were mirrored by those in the literature. Although they are relatively nonspecific when considered in isolation, the cited histopathologic features of cutaneous CPX allow for the diagnosis of this potentially lethal disorder when they are seen in combination with one another, particularly if detailed clinical data also are available.

Neutrophilic lobular (pustular) panniculitis associated with rheumatoid arthritis: a case report and review of the literature

Rheumatoid nodules, which affect the subcutis around joints, are the most frequent specific cutaneous lesions of rheumatoid arthritis (RA). Panniculitis is a rarely reported and nonspecific complication of RA. We report a 42-year-old woman with seropositive RA who presented with a 2-month history of lower leg panniculitis. Biopsy of a leg nodule showed a lobular neutrophilic infiltrate with lipophages and central basophilic necrosis. In addition, focal changes of lipomembranous fat necrosis indicative of ischemic damage were identified at the margins of the lobular infiltrate. Neutrophilic lobular panniculitis is commonly detected in panniculitis secondary to bacterial infections, pancreatitis, and factitial causes. However, this pattern of panniculitis has also been reported in some cases of erythema nodosum-like lesions found in Behçet disease or bowel bypass syndrome and in rare cases of seropositive RA. These reported histologic findings fall into the spectrum of neutrophilic vascular reactions described by Jorizzo and Daniels for RA-associated dermatoses. In view of these findings. RA and related neutrophilic dermatoses (e.g., Behçet disease) should be included in the differential diagnosis of neutrophilic lobular panniculitis.

Diagnosis: erythema nodosum or not?

Erythema nodosum is the final common pathway to a myriad of insults and is thought to be a hypersensitivity reaction centered in the subcutis. To recognize the histological spectrum of erythema nodosum, one must be aware of the morphologic chronology of the disease (early, fully developed, late) and its clinical variants (erythema nodosum migrans). This article reviews the range of changes that can be seen in this prototype of a septal panniculitis and describes the diversity that may be accepted in the diagnosis. Differential diagnoses at each stage of disease development are discussed. The criteria elaborated should assist the pathologist in answering the clinician's query, "Erythema nodosum, or not?"