Development and management of severe cutaneous side effects in head-and-neck cancer patients during concurrent radiotherapy and cetuximab.

BACKGROUND: The concurrent administration of cetuximab to radiotherapy has recently been shown to improve the clinical outcome of head-and-neck cancer (HNC) patients. An aggravation of the radiation-induced skin toxicity was not described. Here, however, two cases with severe skin toxicity during the combined treatment are reported. CLINICAL OBSERVATIONS: In a small group of five patients with locally advanced HNC treated with irradiation and concurrent cetuximab, two cases of unusually severe radiation dermatitis were observed. Both patients developed confluent moist desquamations confined to the irradiation field at a dose of 40 Gy (CTC [Common Toxicity Criteria] grade 3), which progressed into an ulcerative dermatitis (grade 4) at 58 Gy and 46 Gy, respectively. Histopathology showed a vacuolic degeneration of basal keratinocytes, subepidermal blister formation, and mixed perivascular and interstitial inflammatory infiltrates leading to a complete loss of the epidermis. These cutaneous side effects led to the discontinuation of radiotherapy. Topical corticosteroids and systemic antibiotic treatment resulted in wound healing, which allowed the continuation of radiotherapy. CONCLUSION: These findings indicate that cetuximab may have the potential to enhance the severity of radiation dermatitis in HNC patients. A systematic monitoring of cutaneous side effects during radiotherapy plus cetuximab is advised in order to reliably estimate the frequency of severe (grade 3/4) radiation dermatitis.

Eccrine porocarcinoma of the head: an important differential diagnosis in the elderly patient.

BACKGROUND: Eccrine porocarcinoma is a rare malignant tumor of the sweat gland, characterized by a broad spectrum of clinicopathologic presentations. Surprisingly, unlike its benign counterpart eccrine poroma, eccrine porocarcinoma is seldom found in areas with a high density of eccrine sweat glands, like the palms or soles. Instead, eccrine porocarcinoma frequently occurs on the lower extremities, trunk and abdomen, but also on the head, resembling various other skin tumors, as illustrated in the patients described herein. OBSERVATIONS: We report 5 cases of eccrine porocarcinoma of the head. All patients were initially diagnosed as having epidermal or melanocytic skin tumors. Only after histopathologic examination were they classified as eccrine porocarcinoma, showing features of epithelial tumors with abortive ductal differentiation. Characteristic clinical, histopathologic and immunohistochemical findings of eccrine porocarcinomas are illustrated. CONCLUSION: Eccrine porocarcinomas are potentially fatal adnexal malignancies, in which extensive metastatic dissemination may occur. Porocarcinomas are commonly overlooked, or misinterpreted as squamous or basal cell carcinomas as well as other common malignant and even benign skin tumors. Knowledge of the clinical pattern and histologic findings, therefore, is crucial for an early therapeutic intervention, which can reduce the risk of tumor recurrence and serious complications.

Mucous membrane pemphigoid: clinical aspects, immunopathological features and therapy.

More than 50 years have passed since Civatte, Lever, and others described the clinical and histopathological characteristics of mucous membrane pemphigoid (synonym: cicatricial pemphigoid). This enigmatic, relapsing, and often eventually progressive subepithelial blistering disorder of the mucous membranes and skin continues to challenge investigators trying to understand the pathogenesis of the disease and prevent its progression. Mucous membrane pemphigoid typically begins in late adulthood and has a variable prognosis. Fifty percent of patients will develop esophageal and ocular lesions that heal with secondary atrophy leading to stenosis of the upper aerodigestive tract and blindness in uncontrolled disease. Recent progress has been made in understanding the cause, the immunological components, and the pathologic process of mucous membrane pemphigoid. The short-term clinical and pathological manifestations of disease activity have been reduced by new therapies, although the degree of long-term benefit from these treatments awaits further study.

Cutaneous lymphatic malformations in disappearing bone (Gorham-Stout) disease: a novel clue to the pathogenesis of a rare syndrome.

BACKGROUND: Gorham-Stout disease is an unusual, progressive syndrome of unknown etiology characterized by mono- or polyostotic osteolysis most often affecting children and young adults. The onset is insidious and the disease progresses to extensive and potentially disabling osteolysis often unresponsive to therapeutic intervention. Although bone and soft tissue lesions are the most frequent manifestations of Gorham-Stout disease, skin lesions can occur and may provide a clue to the pathogenesis of this rare syndrome. OBJECTIVE: Our aim was to describe characteristics of vascular skin lesions of this rare condition using magnetic resonance imaging and histomorphological analysis. METHODS: The case of a 36-year-old man with Gorham-Stout disease of the left leg and foot is reported. RESULTS: This case was remarkable for its prominent lymphatic vascular malformations involving the skin and soft tissues adjacent to the diseased bone-a previously undescribed abnormality, which preceded osteolysis for several years. Magnetic resonance imaging played a key role in defining the extent of disease in skin and soft tissues. LIMITATIONS: It is difficult to assess the true incidence of hemangiomatosis in the earlier reports on Gorham-Stout disease in which hemangiomatous cutaneous lesions were mentioned but not described or illustrated. CONCLUSION: A vascular process with angiomatous histological features is considered to be the pathological hallmark of Gorham-Stout disease, but the specific type of this vascular process is still under debate. Our report highlights a lymphatic malformative nature of Gorham-Stout disease, thereby contributing to a better understanding and characterization of this rare disease entity.

Arginase 1 overexpression in psoriasis: limitation of inducible nitric oxide synthase activity as a molecular mechanism for keratinocyte hyperproliferation.

Abnormal proliferation of keratinocytes in the skin appears crucial to the pathogenesis of psoriasis, but the underlying mechanisms remain unknown. Nitric oxide (NO), released from keratinocytes at high concentrations, is considered a key inhibitor of cellular proliferation and inducer of differentiation in vitro. Although high-output NO synthesis is suggested by the expression of inducible NO synthase (iNOS) mRNA and protein in psoriasis lesions, the pronounced hyperproliferation of psoriatic keratinocytes may indicate that iNOS activity is too low to effectively deliver anti-proliferative NO concentrations. Here we show that arginase 1 (ARG1), which substantially participates in the regulation of iNOS activity by competing for the common substrate L-arginine, is highly overexpressed in the hyperproliferative psoriatic epidermis and is co-expressed with iNOS. Expression of L-arginine transporter molecules is found to be normal. Treatment of primary cultured keratinocytes with Th1-cytokines, as present in a psoriatic environment, leads to de novo expression of iNOS but concomitantly a significant down-regulation of ARG1. Persistent ARG1 overexpression in psoriasis lesions, therefore, may represent a disease-associated deviation from normal expression patterns. Furthermore, the culturing of activated keratinocytes in the presence of an ARG inhibitor results in a twofold increase in nitrite accumulation providing evidence for an L-arginine substrate competition in human keratinocytes. High-output NO synthesis is indeed associated with a significant decrease in cellular proliferation as shown by down-regulation of Ki67 expression in cultured keratinocytes but also in short-term organ cultures of normal human skin. In summary, our data demonstrate for the first time a link between a human inflammatory skin disease, limited iNOS activity, and ARG1 overexpression. This link may have substantial implications for the pathophysiology of psoriasis and the development of new treatment strategies.