Non-melanoma Hutchinson's sign: a reappraisal of this important, remarkable melanoma simulant.

BACKGROUND: More than 20 years ago, our reappraisal of the Hutchinson's sign (HS) gave birth to the concept of the pseudo-Hutchinson's sign. OBJECTIVES: We have found it interesting to emphasize some important histologic points and to expand the list of the numerous HS simulants. METHODS: We have examined the cutaneous samples taken from the pigmented skin of patients in association with nail matrix biopsy. We have also extended the long list of non-melanoma HS based on comprehensive literature review. RESULTS: Histologically, HS may present only as an epidermal pigmentation, depending on the area sampled. Occasionally, there may be a sparse junctional melanocytic proliferation which does not demonstrate cytologic atypia due to an underlying melanocytic naevus of the nail matrix. However, early HS often shows a melanoma in situ, with a HS at the proximal nail fold (PNF) and confluent "atypical" melanocytes in the nail matrix. Finally, involvement of the PNF, nail matrix and nail bed containing atypical melanocytes in irregular array may be seen in more advanced lesions. The recent literature on non-melanoma HS simulants is summarized and clinical examples are provided. CONCLUSION: The mere presence of periungual pigmentation is neither clinically nor histologically pathognomonic of subungual melanoma and justifies the usefulness of this work stressing the non-melanoma HS.

Classification, clinical manifestations, and immunopathological mechanisms of the epithelial variant of paraneoplastic autoimmune multiorgan syndrome: a reappraisal of paraneoplastic pemphigus.

BACKGROUND: Recent studies suggest that paraneoplastic pemphigus (PNP) is a heterogeneous autoimmune syndrome involving several internal organs and that the pathophysiological mechanisms mediating cutaneous, mucosal, and internal lesions are not limited to autoantibodies targeting adhesion molecules. OBJECTIVE: To classify the diverse mucocutaneous and respiratory presentations of PNP and characterize the effectors of humoral and cellular autoimmunity mediating epithelial tissue damage. METHODS: We examined 3 patients manifesting the lichen planus pemphigoideslike subtype of PNP. A combination of standard immunohistochemical techniques, enzyme-linked immunosorbent assay with desmoglein (DSG) baculoproteins, and an immunoprecipitation assay were used to characterize effectors of humoral and cellular autoimmunity in patients with PNP and in neonatal wild-type and DSG3-knockout mice with PNP phenotype induced by passive transfer of patients' IgGs. RESULTS: In addition to the known "PNP antigenic complex," epithelial targets recognized by PNP antibodies included 240-, 150-, 130-, 95-, 80-, 70-, 66-, and 40/42-kd proteins but excluded DSG1 and DSG3. In addition to skin and the epithelium lining upper digestive and respiratory tract mucosa, deposits of autoantibodies were found in kidney, urinary bladder, and smooth as well as striated muscle. Autoreactive cellular cytotoxicity was mediated by CD8(+) cytotoxic T lymphocytes, CD56(+) natural killer cells, and CD68(+) monocytes/macrophages. Inducible nitric oxide synthase was visualized both in activated effectors of cellular cytotoxicity and their targets. Keratin 14-positive basal epithelial cells sloughed from the large airways and obstructed small airways. CONCLUSIONS: The paraneoplastic disease of epithelial adhesion known as PNP in fact represents only 1 manifestation of a heterogeneous autoimmune syndrome in which patients, in addition to small airway occlusion and deposition of autoantibodies in different organs, may display a spectrum of at least 5 different clinical and immunopathological mucocutaneous variants (ie, pemphiguslike, pemphigoidlike, erythema multiforme-like, graft-vs-host disease-like, and lichen planus-like). We suggest that the more encompassing term "paraneoplastic autoimmune multiorgan syndrome," or PAMS, be applied. The pathophysiological mechanisms of PAMS involve both humoral and cellular autoimmunity responses. Epithelial cell membrane antigens other than DSG1 or DSG3 are targeted by effectors of PAMS autoimmunity. Apoptosis of damaged basal cells mediates epithelial clefting, and respiratory failure results possibly from obstruction of small airways with sloughed epithelial cells.

Eccrine syringofibroadenoma treated with a dual pulse width flashlamp pumped pulsed dye laser.

BACKGROUND: Eccrine syringofibroadenoma is a rare benign eccrine ductal proliferation with a predilection for the extremities, most often found in middle-aged and elderly patients. Reported treatments have included excision and conventional destructive modalities; however, recurrences may be common. OBJECTIVE: We describe a patient with a chronic ulcerated verrucoid eccrine syringofibroadenoma that persisted despite cryotherapy or curettage and electrodessication. RESULTS: Treatment with a dual pulse width flashlamp pumped pulsed dye laser (FPDL) produced an excellent clinical response. CONCLUSION: Treatment of eccrine syringofibroadenoma with a FPDL may provide both a vascular specific injury, analogous to the treatment of verruca vulgaris, and nonspecific thermal destruction at high fluences.

Isotretinoin induced rhabdomyolysis? A case report.

Isotretinoin, an effective therapy for nodulocystic acne and dissecting cellulitis of the scalp, has many known side effects. However, its association with elevated creatine kinase levels and its potential to cause rhabdomyolysis is not well established. We describe a patient with a significant elevation in creatine kinase after beginning therapy with isotretinoin for dissecting cellulitis of the scalp. The implications of isotretinoin causing rhabdomyolysis are discussed.