EWSR1-PBX3 gene fusion in cutaneous syncytial myoepithelioma.

Cutaneous syncytial myoepithelioma (CSM) is a recently recognized, histopathological variant of myoepithelial (ME) tumors of the skin. It is characterized by a syncytial arrangement of spindled, ovoid, and/or epithelioid cells forming a well-circumscribed, unencapsulated dermal nodule. There is a paucity of intervening stroma, and absent duct or gland formation. Strong immunohistochemical staining for S100 and epithelial membrane antigen (EMA) has been described, while cytokeratin expression has been uncommon. The majority of CSMs harbor a rearrangement involving the EWSR1 gene. Although various fusion partner genes have been discovered in ME tumors at other anatomic sites, none has yet been described in CSM. We present a case of CSM represented clinically by a papule on the mid-upper back of a healthy 44-year-old female. It exhibited morphological and immunohistochemical features of a CSM with strong, diffuse S100 and alpha-actin expression, and focal positivity for EMA and cytokeratin AE1/AE3. Fluorescence in-situ hybridization showed an EWSR1 gene rearrangement. Massively parallel next-generation RNA sequencing revealed PBX3 as the fusion partner. The EWSR1-PBX3 gene fusion has been previously identified in three cases of ME tumors of bone and soft tissue, and in a case of retroperitoneal leiomyoma. This is the first report of an EWSR1-PBX3 fusion in CSM.

A Case of Nonuremic Calciphylaxis Treated Effectively With Systemic Corticosteroids.

Calciphylaxis is a syndrome of systemic calcification of the arteries leading to painful tissue necrosis and ulceration. The disease has a high mortality rate with no clear etiology. There is a strong correlation of calciphylaxis with end-stage renal disease, but it can also affect people with normal renal function. Treatment of the disease has been successful at times with various modalities, but in the case of systemic corticosteroids, there is conflicting evidence. In this case report, the authors present a patient with acute nonuremic calciphylaxis who responded very positively to systemic corticosteroids.

Novel case of generalized multinucleate cell angiohistiocytoma.

BACKGROUND: multinucleate cell angiohistiocytoma is a rare benign fibrohistiocytic and vascular proliferation, typically characterized by the development of solitary papules, in an acral distribution in otherwise healthy late middle-aged to elderly women. OBJECTIVE: our objectives are to present a novel case of generalized multinucleate cell angiohistiocytoma and to review the current literature regarding the clinical and histologic findings in this condition, as well as its potential causes and treatments. OBSERVATIONS: we describe a 35-year-old man who presented with generalized asymptomatic firm violaceous papules. Histopathology revealed dermal vascular proliferation; a perivascular infiltrate of lymphocytes, histiocytes, neutrophils, and plasma cells; thickened surrounding collagen bundles; and characteristic multinucleate cells with scalloped borders. CONCLUSION: our patient is one of three patients reported to date with generalized lesions of multinucleate cell angiohistiocytoma who were all in a younger age group (20-40 years old) than previously reported for solitary lesions.

Postirradiation morphea: an underrecognized complication of treatment for breast cancer.

The most common cutaneous side effects of radiotherapy include radiodermatitis and radiation fibrosis. These are influenced by the type, dose, and pattern of delivery of the treatment. Distinct from these is postirradiation morphea (localized scleroderma), an idiosyncratic treatment-related phenomenon. Within the last 20 years, approximately 31 examples of postirradiation morphea after treatment for breast cancer were reported. We describe 5 new cases of this entity and integrate our findings with those in the literature. The mean age of the patients at the time of diagnosis of cancer was 58 years; all were left-sided and treated by local excision of the tumor, ipsilateral axillary lymph node dissection, and local radiotherapy. After an interval of 4 to 12 years, the patients developed morphea in the radiation portals, with extension beyond it in one instance. Recurrent breast carcinoma was suspected clinically in 2 cases. Microscopically, changes of morphea involved the dermis in all cases and the subcutis in 2. There was associated lichen sclerosus et atrophicus in 2 cases. Our data about management and outcome are limited, but 1 patient treated with potent topical steroids experienced gradual softening of the affected skin over a 5-year period, whereas another had a mastectomy for relief of painful induration of the breast. Our findings support existing theories about the pathogenesis of this condition and link it to those of sclerodermoid graft-versus-host disease. The purpose of our communication is to draw attention to this underrecognized complication of treatment for breast cancer.

Histiocytoid neutrophilic dermatoses and panniculitides: variations on a theme.

Requena et al, in their article titled "Histiocytoid Sweet syndrome," in 2005, established that the dermal infiltrate in some patients with Sweet's syndrome is composed of histiocyte-like immature myeloid cells, not polymorphonuclear leukocytes as is the norm. With this premise in mind, we report on 6 cases of inflammatory skin disease in which the common denominator was a dermal and/or subcutaneous infiltrate of histiocytoid myeloid cells in patients with new-onset cutaneous eruptions and systemic symptoms. The cases were diverse clinically and microscopically, fell short of the criteria necessary for a diagnosis of classical Sweet's syndrome, and were difficult to categorize at the outset. The systemic manifestations ranged from malaise alone to a combination of fever, chills, night sweats, and polyarthralgia. The clinical morphology of the cutaneous eruptions varied from being papulovesicular in 1 patient to mainly consisting of erythematous plaques and nodules in the remainder. The dermatologists' differential diagnoses included Sweet's syndrome in 3 cases, a drug eruption in 2, and other entities such as erythema nodosum and Well's syndrome. Biopsies in all cases revealed a dermal and/or subcutaneous infiltrate composed predominantly of mononuclear histiocytoid cells of myeloid origin. With the benefit of detailed clinicopathologic correlation, the cases were classified for the purpose of this report as follows: Sweet's-like neutrophilic dermatosis, histiocytoid (3 cases); subcutaneous Sweet's syndrome, histiocytoid (2 cases); histiocytoid neutrophilic dermatosis, unspecified (1 case). In addition, we describe a further instructive case that exhibited overlap with those in the series but proved ultimately to represent leukemia cutis. The spectrum of observations in this report supports and expands the original concept of histiocytoid Sweet's syndrome.