Panniculitis

Panniculitis: clinical overlap and the significance of biopsy findings

BACKGROUND

Panniculitides are well-recognized clinicopathologic entities but the non-specificity of their clinical and pathological features often troubles the diagnostician.

METHODS

This study retrospectively evaluates the clinical overlaps and the significance of histological findings among various panniculitides.

RESULTS

The clinical evaluation in 55 panniculitides cases suggested the diagnosis of typical erythema nodosum (EN) in 26 cases, atypical EN in 17 cases, atypical nodular vasculitis (NV) in two cases, soft tissue infection in five cases and five cases remained unclassified. Skin biopsy evaluation provided definite panniculitis diagnosis in 53 cases including EN (28 cases), leukocytoclastic vasculitis (seven cases), NV (four cases), superficial thrombophlebitis (ST) (two cases), eosinophillic panniculitis (EP) (three cases), infection-related panniculitis (five cases), and one case each of erythema nodosum leprosum (ENL), lupus panniculitis (LP), pancreatic fat necrosis and acne conglobata with two cases remaining unclassified. Histologically, 'predominantly septal' and 'mixed panniculitis' were the chief inflammatory patterns in EN cases, while mixed panniculitis was seen in most LCV cases and predominantly lobular and mixed panniculitis in NV cases.

CONCLUSIONS

Biopsy evaluation of a panniculitis lesion is usually significant, and the application of a combination of histologic features rather than of a single biopsy finding or an inflammatory pattern is helpful in the diagnosis of panniculitis.

Sclerema neonatorum: a review of nomenclature, clinical presentation, histological features, differential diagnoses and management

OBJECTIVE

To review published literature on sclerema neonatorum (SN) in order to clarify its clinical presentation, histological features and management compared with two other diseases: subcutaneous fat necrosis of the newborn (SCFN) and scleredema.

STUDY DESIGN

PubMed database was searched using the key words Sclerema neonatorum. A total of 55 articles from peer-reviewed journals were reviewed and summarized.

RESULT

SN, SCFN and scleredema are diseases of the subcutaneous adipose tissue. SN is characterized by hardening of the skin that gets bound down to the underlying muscle and bone, hindering respiration and feeding and is associated with congenital anomalies, cyanosis, respiratory illnesses and sepsis. Histology of the skin biopsy shows thickening of the trabeculae supporting the subcutaneous adipose tissue and a sparse inflammatory infiltrate of lymphocytes, histiocytes and multinucleate giant cells. SCFN has circumscribed hardening of skin on bony prominences with necrosis of adipocytes in subcutaneous tissue and a dense granulomatous infiltrate on histology. Scleredema is characterized by hardening of the skin along with edema; histology shows inflammatory infiltrate and edema in skin and subcutaneous tissues. SN has a high case fatality rate whereas SCFN and scleredema are self-limiting and lesions resolve within a few weeks to months. Exchange transfusion may improve survival in SN.

CONCLUSION

The histological features of skin biopsy should be used to establish diagnosis of SN, SCFN and scleredema as disease-specific treatment is imperative in SN due to high fatality.

Panniculitis. Part II. Mostly lobular panniculitis

The second part of our review of panniculitis summarizes the clinicopathologic features of the mostly lobular panniculitides. Erythema induratum of Bazin (nodular vasculitis) represents the most common variant of lobular panniculitis with vasculitis, although controversy persists about the nature of the involved vessels. Mostly lobular panniculitides without vasculitis comprise a series of disparate disorders. These include sclerosing panniculitis that results from chronic venous insufficiency of the lower extremities; panniculitis with calcification of the vessel walls such as calciphylaxis and oxalosis; and inflammatory diseases with crystals within the adipocytes such as sclerema neonatorum, subcutaneous fat necrosis of the newborn, and poststeroid panniculitis. Connective tissue diseases, such as systemic lupus erythematosus and dermatomyositis, pancreatic diseases, and alpha(1)-antitrypsin deficiency may also show a mostly lobular panniculitis with characteristic histopathologic features. Lobular panniculitis may also be an expression of infections, trauma, or factitial causes involving the subcutaneous fat. Lipoatrophy refers to a loss of subcutaneous fat due to a previous inflammatory process involving the subcutis, and it may be the late-stage lesion of several types of panniculitis. In contrast, lipodystrophy means an absence of subcutaneous fat with no evidence of inflammation and often the process is associated with endocrinologic, metabolic, or autoimmune diseases. Finally, cytophagic histiocytic panniculitis is the term that has been used to describe two different processes: one is inflammatory, a lobular panniculitis, and the other one is neoplastic, a subcutaneous T-cell lymphoma. The only common feature of these two different processes is the presence of cytophagocytosis in the lesions. (J Am Acad Dermatol 2001;45:325-61.)

LEARNING OBJECTIVE

At the completion of this learning activity, participants should be familiar with the pathogenesis, clinical manifestations, histopathologic findings, and treatment options for the most frequent variants of the lobular panniculitides.

The histopathologic spectrum of erythema induratum of Bazin

Erythema induratum of Bazin is a tuberculid that is strongly associated with tuberculosis. Clinically, erythema induratum of Bazin show recurrent tender subcutaneous nodules that occur mainly on the calves of women with tuberculin hypersensitivity. Previous studies have not documented the histopathologic spectrum of erythema induratum of Bazin in detail. We identified two major histopathologic groups in 19 of 20 skin biopsies obtained from 20 patients with well-documented erythema induratum of Bazin. Six cases (group I) showed focal septolobular panniculitis in close association with a single muscular artery or small vessel with primary neutrophilic vasculitis. Thirteen cases (group II) revealed diffuse septolobular panniculitis with primary neutrophilic vasculitis of either large or smaller vessels. Both groups showed varying combinations and degrees of acute and chronic inflammation, coagulative and caseation-like necrosis, and granulomatous inflammation. Poorly developed granulomas predominated, but mixed, palisading, and lipophagic granulomas also occurred. Inflammation and necrosis were more extensive in group II. Erythema induratum of Bazin may show predominantly acute suppurative or granulomatous panniculitis. Immunostaining showed S100+ antigen-presenting cells, macrophages, and T-lymphocytes. B-lymphocytes were rare. The presence of primary vasculitis and granulomas suggests that types III and IV hypersensitivity reactions play a role in the pathogenesis or erythema induratum of Bazin. The latter remains a clinicopathologic diagnosis, but awareness of the heterogeneous histopathologic spectrum of EIB will ensure a timely diagnosis and institution of antituberculous treatment.

Tick bites in Korea

BACKGROUND

Tick bites are dermatoses not commonly encountered in Korea. Recognizing their clinical signs as well as their histopathologic findings is important in making a diagnosis of tick-related dermatoses. The incidence and causative species are different depending on the geographic areas. The histopathologic findings of tick bites are known to be a variable depending on the species of ticks involved and the duration of their bloodsucking.

METHODS

Five ticks were collected from five patients and three of them were identified as Ixodes (I.) nipponensis.

RESULTS

Histopathologic findings of panniculitis were prominent in four of five cases; septal panniculitis in two cases, and lobular panniculitis in the other cases.

CONCLUSIONS

Ixodes nipponensis was the most common causative species of ticks responsible for tick bites in Korea, and tick bite panniculitis must be considered in the differential diagnosis of panniculitis which is mainly composed of neutrophils.

Erythema nodosum versus nodular vasculitis

BACKGROUND

Erythema nodosum (EN) is usually considered to be a septal panniculitis, and nodular vasculitis (NV) a lobular panniculitis. We tested the usefulness of this histologic classification in clarifying a frequent clinical dilemma: EN versus NV.

METHODS

Over 3 years 109 patients with panniculitis were included in this study. After a history and a physical examination, a clinical diagnosis was made according to well-established criteria.

RESULTS

From the study of 88 patients, we concluded that in the clinically typical cases, the clinico-pathologic agreement was 93% and 94% for EN and NV respectively, whereas it diminished to 79%, 72%, and 67% in the cases clinically diagnosed as EN migrans, atypical EN, and atypical NV, respectively. Moreover, septal and lobular panniculitis were always two clear-cut, different, opposite patterns of hypodermal inflammation to these conditions.

CONCLUSIONS

In the absence of a known pathogenetic mechanism, the histopathology remains the most objective discriminating marker between EN and NV, mainly in the clinically atypical and doubtful cases.

Eosinophils in lupus panniculitis and morphea profunda

The extent of eosinophils in skin biopsy and peripheral blood specimens of patients with lupus panniculitis and morphea profunda was determined by studying 37 biopsies from 33 patients with lupus panniculitis and 55 biopsies from 53 patients with morphea profunda. Specimens from 8 (24%) of 33 patients with lupus panniculitis showed eosinophils, and 13 (25%) of 53 patients with morphea profunda had eosinophils in the subcutaneous tissue. In all cases, the diagnosis of lupus panniculitis or morphea profunda was established on the basis of other, more characteristic histologic features; the presence of eosinophils was incidental and not a diagnostic criterion. Occasional cases of lupus panniculitis or morphea profunda had numerous eosinophils. However, in most of the specimens, eosinophils were absent or observed in small numbers. Only 3% of patients with lupus panniculitis showed an increase in the number of eosinophils in the peripheral blood, whereas 47% of patients with morphea profunda had peripheral eosinophilia. The degree of hyaline necrosis in lupus panniculitis or of sclerosis in morphea profunda did not correlate with the number of eosinophils present in the biopsy specimen or peripheral blood.

Dermatomyositis associated with multifocal lipoatrophy

A 10-year-old boy had juvenile dermatomyositis and multiple asymmetric lesions of lipoatrophy. The lipoatrophy had occurred without preceding clinical evidence of inflammation. Biopsy specimens of the skin confirmed a lobular panniculitis. This is the first report of the association of lipoatrophy and juvenile dermatomyositis.

Calcium oxalate and other crystals associated with kidney diseases and arthritis

The recognition of tissue deposits of crystalline material in a variety of organs, including the kidney, predated the association of crystals and arthritic disease. Because of this, the pathophysiology of crystal formation and its resultant inflammation is based in part on studies of renal stones. A number of disease states involving renal and articular crystallization exist. The most common of these, uric acid precipitation, or gout, and calcium phosphate precipitation were not reviewed in this discussion. This review described a variety of less common disease states involving articular and renal crystal deposition. The renal diseases discussed included both parenchymal or ectopic crystal deposition, as seen in nephrocalcinosis or cystinosis, and ductal crystallization as seen in renal calculus disease. The crystals involved included not only calcium oxalate, but also aluminum, amino acids and proteins (cystine, hemoglobin, cryoglobulins, and immunoglobulins), purine metabolites (xanthine, hypoxanthine), and even lipids and their degradative enzymes (cholesterol, phospholipids, phospholipase, and fatty acids). The simultaneous occurrence of crystals in both kidneys and joints was found in some cases to result from the systemic deposition of an excess of a particular biological compound. However, of more interest, some renal deposits were shown to more selectively reflect the normal or abnormal function of the kidney in its secretory and excretory roles. This is particularly evident in the variety of arthritic states described in end-stage renal disease.