Late-stage nodular erythema elevatum diutinum

Epithelioid fibrous histiocytoma: three diagnostically challenging cases with novel ALK gene fusions, unusual storiform growth pattern, and a prominent spindled morphology

Epithelioid fibrous histiocytoma (EFH) is a distinctive cutaneous neoplasm with a relatively variable morphological appearance. Recently, it has been shown that this tumor is molecularly characterized by ALK gene fusions. We report three EFHs with unusual histological presentation represented by a prominent/predominant spindle cell proliferation arranged in a variably storiform/whirling architectural pattern with or without stromal sclerosis. One of the cases closely resembled cellular fibrous histiocytoma. All three cases were immunohistochemically ALK-positive and were analyzed for ALK gene rearrangements using a next-generation sequencing-based assay (FusionPlex Sarcoma Kit, ArcherDx). Three novel fusions, namely AP3D1::ALK, COL1A::ALK, and LRRFIP2::ALK, were detected and further confirmed by FISH in all 3 cases and RT-PCR in 1 case. All patients were elderly (62-63 years) and presented with a solitary polypoid lesion on the extremities. The awareness of these morphological variants is important since it entertains a wide and slightly different differential diagnosis than conventional EFH. We also presented evidence that a clear separation of EFH from BFH in all cases may not be as straightforward as previously thought. The consistent ALK immunoexpression and the continually expanding scale of ALK gene rearrangements provide a useful tool to distinguish EFH from its histologic mimics.

Vasculitis

Vasculitis, characterized by inflammation and necrosis, manifests a wide spectrum of presentation by involving a vasculature of various sizes and locations. A definitive diagnosis of vasculitis invariably requires histologic confirmation since there are no diagnostic clinical, imaging, or laboratory findings. The most widely adopted vasculitis classification is the Chapel Hill Consensus Conference (CHCC) nomenclature of systemic vasculitis which integrated clinical symptoms, histopathologic features, and laboratory findings. This classification accounts for the size of the involved vessels. This chapter outlines the clinical and histologic features of the small-vessel vasculitis including the immune complex vasculitis and antineutrophil cytoplasmic antibody-associated vasculitis; medium-vessel vasculitis such as polyarteritis nodosa and Kawasaki disease; large-vessel vasculitis, namely, giant cell arteritis and Takayasu arteritis; variable-vessel vasculitis such as Behcet disease and Cogan syndrome; and vasculitis associated with systemic diseases including rheumatoid arthritis, lupus vasculitis, and sarcoid vasculitis. Vasculitis can also be secondary to drugs, infection, underlying systemic disease, or trauma. Therefore, a diagnosis of vasculitis cannot be based on histologic ground alone. Clinical pathologic correlation is necessary.

Erythema elevatum diutinum: a case report and review of literature

Erythema elevatum diutinum (EED) is a rare cutaneous leukocytoclastic vasculitis thought to be related to increased levels of circulating antibodies. It has been shown to be associated with HIV infection, tuberculosis, as well as various autoimmune diseases. A retrospective review of all cases of EED indexed in PubMed between 1990 and 2014 was performed. Inclusion criteria for articles was availability of full text in English and a biopsy-confirmed diagnosis of EED. All other articles were excluded. Cases were stratified by age and anatomic location of the lesions. Treatment response was coded as "complete," "partial," and "none." A total of 133 cases of EED with 381 lesions detailed in case reports and case series were included. Twenty-one cases were associated with HIV. Of 47 patients with reported paraproteinemias, IgA paraproteinemia was found in 57.45%, IgG paraproteinemia in 29.8%, IgM paraproteinemia in 10.6%, and IgD paraproteinemia in 2.1% of cases. Of 40 (30.1%) patients with reported comorbid autoimmune disease, rheumatoid arthritis was associated with 10 cases. Cancer was found to be associated with 9.77% of cases. Seventy-five patients were treated with dapsone, with 36 (48%) achieving complete treatment response, 24 (32%) achieving partial response, and seven (9.3%) achieving no response. Keeping the clinical associations of EED in mind, especially malignancy, is critical in management of the disease. More structured studies need to take place in order to fully define the mechanisms and strength of these associations.

Late-stage nodular erythema elevatum diutinum mimicking sclerotic fibroma

Erythema elevatum diutinum (EED) is a rare, cutaneous vasculitis of uncertain origin. EED can present clinically as chronic bilateral, symmetrical, periarticular papules, plaques and nodules. We report here an unusual case of EED presenting as multiple, densely fibrosing nodules on the feet of a 60-year-old human immunodeficiency virus positive woman. The initial evaluation of the patient was complicated by the strong histologic resemblance of multiple lesions to sclerotic fibroma, a cutaneous manifestation of Cowden disease. Our case highlights the important features that distinguish these 2 pathologic entities.

Nodular Erythema Elevatum Diutinum Mimicking Kaposi's Sarcoma in a Human Immunodeficiency Virus Infected Patient

Erythema elevatum diutinum (EED) has been emerging as a specific Human Immunodeficiency Virus (HIV) associated dermatosis in recent times. It is an extremely rare chronic disease of unknown origin and part of the spectrum of leukocytoclastic vasculitis. We describe a case of EED simulating Kaposi's sarcoma in a 52-year-old HIV infected female patient with no previous opportunistic infections and CD4+ count of 164/mm(3). Therapy with oral dapsone (100 mg/day) for two weeks resulted in resolution of some lesions.

Erythema elevatum diutinum in systemic lupus erythematosus

Erythema elevatum diutinum (EED) is a rare chronic form of leukocytoclastic vasculitis with unknown etiology. EED has been described in association with hematological malignancies, infections and a number of rheumatological diseases. We report a patient with systemic lupus erythematosus (SLE) who presented with intermittent attacks of tender nodules and plaques on the shins and ankles for 6 months. Skin biopsy confirmed the diagnosis of EED. Treatment with dapsone resulted in complete resolution of the skin lesions. EED is rarely reported in SLE, and its presentation and treatment is reviewed.

[Case for diagnosis. Erythema elevatum diutinum]

Erythema elevatum diutinum is a rare presentation of cutaneous vasculitis. Typical lesions are papules, plaques, and nodules that may coalesce and later turn to yellow-brown color. The extensor surface of the extremities is the most involved area and older lesions may present xanthomatous appearance. Light microscopy of acute lesions shows neutrophilic, perivascular infiltrate with dermal fibrin deposits, endothelial expansion, and leukocytoclasis. We present a case of erythema elevatum diutinum without associated disease.

Sclerotic fibroma-like change in various neoplastic and inflammatory skin lesions: is sclerotic fibroma a distinct entity?

Sclerotic fibroma was first described in association with Cowden's disease by Weary et al. in 1972. In 1989, Rapini and Golitz detailed 11 cases of solitary sclerotic fibroma (SFS) in the absence of Cowden's disease, suggesting the term SFS of the skin. Classic histological features include hypocellular, hyalinized bands of collagen sharply demarcated from the surrounding skin. Numerous authors have described sclerotic fibroma-like changes in other entities including melanocytic nevi, dermatofibromas, lipomas, tendon sheath fibromas, giant cell collagenomas, neurofibromas, angiofibromas, erythema elevatum diutinum, and folliculitis. Dissension has arisen, with some dermatopathologists asserting that sclerotic fibroma is just an evolutionary end-point of a previous lesion. Others contend that SFS is a distinct lesion and cite recurrent cases and/or proliferation marker studies to corroborate this view. We detail the histopathological findings of lesions consistent with the classic description of SFS and compare these to sclerotic changes observed in an intradermal nevus, blue nevus, erythema elevatum diutinum, neurofollicular hamartoma, angiofibroma, neurofibroma, accessory nipple, and dermatofibromas. Sclerotic fibroma-like change may be seen in a variety of lesions and may represent a common reaction pattern in the skin.