Incipient intraepidermal cutaneous squamous cell carcinoma: a proposal for reclassifying and grading solar (actinic) keratoses

Actinic keratoses (AKs) are primarily induced by ultraviolet (UV) radiation and are often identified as premalignant lesions. In our opinion, AKs are proliferations of transformed, neoplastic keratinocytes confined to the epidermis that may eventually extend into the dermis, at which point they are termed squamous cell carcinoma (SCC). In contrast to AKs, SCCs have the potential to metastasize and kill. This process is analogous to that of evolving carcinoma of the uterine cervix that has been termed cervical intraepithelial neoplasia (CIN), a time-tested and reliable classification that provides clinicians with accurate information on which to base treatment decisions regarding cervical neoplasms following biopsy testing. A similar classification scheme could provide guidance to clinicians for the diagnosis and treatment of evolving SCC of the skin and as such, we propose a similar classification using the terminology keratinocytic intraepidermal neoplasia (KIN). This system is more reflective of the histology and natural history of SCC and eliminates ambiguity in the terminology of lesions currently referred to as AKs. The KIN classification defines features by which individual specimens can be objectively graded and specific treatment recommendations are made based on the grade of the lesion. We propose that the term keratinocytic intraepidermal neoplasia (KIN) be used to define and describe evolving SCC of the skin and that the term actinic (solar) keratosis be eliminated.

Disseminated sporotrichosis with extensive cutaneous involvement in a patient with AIDS

Sporotrichosis most commonly presents as a localized, lymphocutaneous infection that follows trauma, such as an injury from a rose thorn. In patients infected with HIV, it may be widespread and disseminated. We describe a patient with AIDS who developed disseminated sporotrichosis, a rare opportunistic fungal infection that may affect these patients. The condition remained undiagnosed because of failure to recognize characteristic histopathologic findings and failure of clinicians to interface closely with the microbiology laboratory. The condition was difficult to treat, requiring systemic administration of amphotericin. While localized sporotrichosis is an innocuous disorder that responds well to therapy, in immunocompromised hosts, it is potentially life-threatening and may require prolonged therapy with potentially toxic medications such as amphotericin B. It is important that clinicians be aware of the presentation of this unusual opportunistic infection and that they maintain close communication with pathology and clinical microbiology laboratories to ensure that proper stains and cultures are performed to avoid potential misdiagnosis.

A potpourri of parasitic infestations

Ectoparasitic infestations are common cutaneous problems. The vast majority of these are attributable to scabies and pediculosis. While these are usually readily recognizable, infestations caused by other ectoparasites, such as nonscabetic mites, may pose difficulty in diagnosis. In this article, we present a variety of ectoparasitic infestations that initially eluded diagnosis and review the gamut of ectoparasites that can cause eruptions in the skin.

Topical and intralesional cidofovir: a review of pharmacology and therapeutic effects

BACKGROUND

Cidofovir is a potent nucleoside analog antiviral drug approved for the treatment of cytomegalovirus (CMV) retinitis in patients with AIDS. It is currently available only for intravenous infusion. Several small studies and case reports describe the successful use of cidofovir applied either topically or intralesionally in several virally induced cutaneous diseases.

OBJECTIVE

Our purpose was to review the usefulness of topical and intralesional cidofovir for the treatment of viral infections caused by human papillomavirus, herpesviruses (including acyclovir-resistant strains), Kaposi's sarcoma-associated herpesvirus, and molluscum contagiosum.

METHODS

We performed a review of recent literature.

RESULTS

Cidofovir is a potent topical intralesional antiviral agent with activity against several DNA viruses that cause cutaneous disease. No significant systemic side effects have been noted, although application site reactions are common and can occasionally be severe.

CONCLUSION

The effective use of topical and intralesional cidofovir for the treatment of diseases of the skin caused by DNA viruses has been demonstrated in a limited number of patients including those infected with HIV. Although larger studies will be necessary to determine the specific function that topical cidofovir will have in the treatment of cutaneous diseases caused by DNA viruses, the drug offers significant promise.

Update on cutaneous manifestations of HIV infection

The skin is affected in virtually all patients with HIV infection. Many articles and several books have been published that deal with these disorders for a number of reasons. First, cutaneous disease may serve as the initial or only problem that the patient suffers for much of the course of the HIV infection. Second, serious opportunistic infections may present for the first time in the skin, so that a skin lesion may be a harbinger of the patient's having a life-threatening illness. Third, skin disorders in these patients may appear unusual and hence may not be accurately diagnosed by clinical inspection alone. Furthermore, response to treatment may be poorer than expected. Thus, skin diseases in the HIV-infected patient are important and, in some cases, may be the most debilitating element of the patient's condition.

Eccrine syringofibroadenomatosis associated with hidrotic ectodermal dysplasia

Eccrine syringofibroadenoma (ES) is generally regarded as a solitary benign adnexal neoplasm of the skin. Recently, the epithelial and stromal changes of this lesion have been recognized as being a reaction pattern in certain settings. We describe two individuals in whom this process was a manifestation of hidrotic ectodermal dysplasia. In both cases, the diagnosis had been missed for many years and the process had been thought to be a manifestation of an inflammatory dermatosis of the palms and soles. In both instances, other family members were found to be affected. Thus, ES may be manifested clinically as erythematous erosive plaques, especially of the palms and soles. It is important that clinicians be familiar with this disorder and be aware that it may exhibit unusual cutaneous manifestations.

Vesiculo-bullous dermatomyositis

Cutaneous manifestations of dermatomyositis (DM) commonly include Gottron's papules, cuticular erythema and telangiectasia, periorbital edema with a "heliotrope" rash, a papulosquamous eruption of the hairline, face, and trunk, as well as poikiloderma. Very few references can be found concerning vesicular and bullous lesions, however. We present two patients with dermatomyositis who manifested vesicular and bullous lesions who were initially misdiagnosed. Although rare, it is important to recognize this form of DM to avoid misdiagnosis. Furthermore, in some cases, vesiculo-bullous DM may portend a poor prognosis.

Histologic differentiation of desmoplastic melanoma from cicatrices

Desmoplastic malignant melanoma (DMM) is a rare variant of melanoma that can be very difficult to diagnose correctly both clinically and histologically. The problem is compounded by the fact that many lesions persist at previous biopsy or excision sites so that scar tissue is often present admixed with or adjacent to the spindle cell neoplasm which may exhibit fibroblastic differentiation itself. In order to assess this problem, we compared and contrasted the histologic features of six DMM with 15 examples of cicatrices from various sources. Mature scars were readily differentiated from DMM by light microscopy. In contrast, immature scar and DMM had many features in common including hypercellularity, nodular lymphoid infiltrates, myxoid stroma, and atypical nuclei. The presence of a melanocytic proliferation within the epidermis above the dermal component, neurotropism, and S-100 and/or HMB-45 positivity of neoplastic cells were the only features that permitted reliable differentiation between the two. Clinical correlation and review of previous biopsy specimens are crucial in preventing a delayed diagnosis of DMM. Re-excision is advised in all questionable cases.

Bacillary angiomatosis and other Bartonella species infections

Infections with organisms of the genus Bartonella, for many years important only in South and Central America, have assumed significance in developing countries, especially in conjunction with the advent of the pandemic of the human immunodeficiency virus infection. New molecular and culture techniques have determined that these organisms cause new diseases such as bacillary angiomatosis as well as diseases the etiology of which have been unknown such as cat scratch disease. In this article, the microbiology, pathogenesis, histopathology and clinical manifestations of diseases caused by these organisms are discussed.

Actinic keratoses. Differential diagnosis and treatment

Actinic keratoses are extremely common premalignant keratinocytic neoplastic lesions that develop primarily in fair-complexioned individuals during midlife or beyond. Genetic, occupational and other environmental factors predispose to the development of these lesions. Without treatment, a significant number may progress to fully developed neoplasms, especially squamous cell carcinoma, over a period of 20 to 50 years. The multistep theory of carcinogenesis is helpful in understanding the pathogenesis and progression of this important and highly prevalent lesion.

Eruptive melanocytic nevi after Stevens-Johnson syndrome

Widespread melanocytic nevi may rarely appear suddenly after a severe bullous disease. We describe two patients in whom eruptive melanocytic nevi developed 3 weeks after a severe episode of Stevens-Johnson syndrome. Benign melanocytic proliferation may develop after a bullous dermatosis and should not be confused with malignant or metastatic melanoma.

Langerhans' cell histiocytosis in adults

Three cases of Langerhans' cell histiocytosis with unusual clinical and histopathologic features are described. The first two cases illustrate diagnostic pitfalls that underscore the importance of considering Langerhans' cell histiocytosis in the differential diagnosis of purpuric papular eruptions of the scalp and intertriginous areas, particularly in association with hypothalamic, pituitary, or liver disease. The third case is the first report of Langerhans' cell histiocytosis presenting as a vesicular eruption.

Expression and mutation of the tumor suppressor gene p53 in AIDS-associated Kaposi's sarcoma

Alteration of the p53 gene is the most frequent event reported in human cancer, and p53 mutations have been observed in various neoplasms, including certain forms of skin cancer. Therefore, we postulated that p53 may also be involved in Kaposi's sarcoma associated with AIDS (AIDS-KS). Expression of the p53 gene was examined in freshly isolated tumor biopsy specimens from 15 patients with AIDS-KS. p53 mRNA was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) in both the AIDS-KS tumors and in normal skin control samples. p53 protein was detected in 4 of the 15 AIDS-KS specimens by immunohistochemical staining. Single-strand conformation polymorphism analysis PCR-products (PCR-SSCP) was used for detection of mutations of the p53 gene. One of the p53 positive AIDS-KS samples showed mobilized shifts in exon 6 suggestive of a mutation. Sequencing data showed the mutation to be located in codon 210. We examined other mechanisms that could stabilize p53 protein. SV40 large T antigen and adenovirus E1B protein were not found in the AIDS-KS specimens. MDM2, a p53-binding protein, was also detected in five of the AIDS-KS specimens, two of which also contained p53-positive cells. These observations suggest that the tumor suppressor gene p53 may be involved in the pathogenesis of AIDS-KS.

Biopsy technique for pigmented lesions

The biopsy technique that should be used when sampling a pigmented lesion may not always be readily apparent. The final arbiter is whether the specimen that will be generated will be representative of the entire process so that an accurate and complete diagnosis will be able to be rendered. In some cases, melanoma may not be clinically suspected so that it is essential that any biopsy that is performed will detect these lesions.

Cutaneous malignant melanoma: classification and clinical diagnosis

Cutaneous malignant melanoma (MM) is a treacherous disease which carries high mortality rates. However, when diagnosed early it is wholly curable. The incidence of MM is rising steadily. The most important clinical signs include the appearance of a newly acquired pigmented lesion or change in a preexisting one. Melanoma has been classified into subtypes which include melanoma in situ, lentigo maligna melanoma, nodular melanoma, acral lentiginous melanoma, desmoplastic melanoma, superficial spreading melanoma, and mucosal melanomas. Although these overlap, there are characteristic clinical features of each that are generally recognizable. Evaluation of pigmented lesions requires correlation of clinical findings with risk factors, family history and histology. A representative skin biopsy should be performed on any lesion suspected of being MM, even if the possibility is remote.