Primary cutaneous immunocytoma. A B-cell lymphoma that can easily be mistaken for cutaneous lymphoid hyperplasia.

It has been estimated that immunocytomas comprise roughly 2% of all cutaneous lymphomas. We studied five patients with primary cutaneous immunocytomas who presented with cutaneous nodules or plaques. Many of the infiltrates were "top-heavy" and polymorphous with admixed eosinophils, macrophages, lymphoid follicles, and non-neoplastic lymphocytes.

The histopathologic spectrum of palisaded neutrophilic and granulomatous dermatitis in patients with collagen vascular disease.

Background And Design: Patients with lupus erythematosus, rheumatoid arthritis, and other diseases in which circulating immune complexes occur can develop a papular eruption on the extremities. Terms including Churg-Strauss granuloma, cutaneous extravascular necrotizing granuloma, rheumatoid papules, superficial ulcerating rheumatoid necrobiosis, and interstitial granulomatous dermatitis with arthritis have been given to this entity. We evaluated the clinical and histopathologic features of six patients with systemic lupus erythematosus, two patients with rheumatoid arthritis, and one patient with an incompletely characterized collagen vascular disease who developed cutaneous papules.

S-100 protein-negative malignant melanoma: fact or fiction? A light-microscopic and immunohistochemical study.

S-100 protein is considered a characteristic immunohistochemical marker for all nevomelanocytic lesions, in which it is expected to be present consistently. We reviewed 17 cases of malignant melanomas that previously tested negative for S-100 protein. They were reevaluated by light microscopy, a broad panel of immunohistochemical reagents including monoclonal and polyclonal antibodies to S-100 protein, and electron microscopy.

Granulomatous slack skin.

Granulomatous slack skin is a form of cutaneous lymphoma with an indolent but relentless course. It is characterized by circumscribed areas of pendulous lax skin that contain clonal infiltrates of helper T-cells, which infiltrate the epidermis in a manner similar to that of mycosis fungoides and attract a granulomatous component that mediates massive dermal elastolysis. The evolution of Hodgkin's disease occurs in some cases.

Smooth-muscle proliferation in dermatofibromas.

Although a variety of epithelial changes have been associated with dermatofibromas, mesenchymal proliferations induced by dermatofibromas appear to be rare. We report three dermatofibromas that were associated with proliferation of smooth muscle within the adjacent dermis. The lesions ranged from a large, densely cellular dermatofibroma with "monster cells" to a sparsely cellular, fibrous lesion.

Thick-section fluorescence in situ hybridization on formalin-fixed, paraffin-embedded archival tissue provides a histogenetic profile.

Fluorescence in situ hybridization has become a major tool for analysis of gene and chromosome copy number in normal and malignant tissue. The technique has been applied widely to fresh tissue and dispersed formalin-fixed, paraffin-embedded archival tissue, but its use on sections of archival tissue has largely been limited to sections < 6 mu thick. This does not provide intact, uncut nuclei for accurate analysis of gene or chromosome copy number.

Overexpression of p53 tumor suppressor protein in porokeratosis.

Background: p53 is a tumor suppressor nucleoprotein. Mutations of the p53 gene have been found in a variety of malignant neoplasms. Wild-type p53 has a short half-life, possibly only 20 to 30 minutes, and is not present in the nucleus at levels that are detectable with routine immunohistochemical techniques.

p53 oncoprotein expression and proliferation index in keratoacanthoma and squamous cell carcinoma.

Background And Design: Whether solitary keratoacanthoma (KA) is a malignant neoplasm despite its self-limited clinical behavior, and the distinction between KA and squamous cell carcinoma (SCC) are related aspects of a long-standing debate among dermatopathologists. Recent advances toward understanding the molecular basis of malignant transformation may allow this issue to be resolved. Mutant p53 tumor-suppressor protein has been shown to accumulate in cutaneous SCC and other tumors, and may be a relatively specific marker of malignancy.

Interphase cytogenetics of melanocytic neoplasms: numerical aberrations of chromosomes can be detected in interphase nuclei using centromeric DNA probes.

This study shows that fluorescence in situ hybridization (FISH) to thin sections cut from paraffin-embedded material can be used to distinguish between groups of melanocytic neoplasms and thus may be useful as an investigational and diagnostic tool. FISH with a probe for a repeated, alpha satellite sequence specific to chromosome 17 was used to investigate the chromosomal composition of dysplastic (or Clark's nevus) and Spitz's nevi and malignant melanomas. Hybridization was to thin (approximately 6 microns) sections cut from paraffin blocks.

Simulants of malignant melanoma: a rogue's gallery of melanocytic and nonmelanocytic imposters.

Although overdiagnosis of malignant melanoma involves no potential loss of life, it affects the patient profoundly and therefore should be addressed conscientiously. This review of both benign and malignant, melanocytic and nonmelanocytic simulants of malignant melanoma emphasizes the pitfalls and repercussions of misdiagnosis. For more accurate differentiation, simulants are classified first as superficial (intraepidermal) or deep (dermal), then as melanocytic or nonmelanocytic.

Microcystic adnexal carcinoma of the skin. A reappraisal of the differentiation and differential diagnosis of an underrecognized neoplasm.

Background: Microcystic adnexal carcinoma (MAC) is a locally aggressive adnexal neoplasm whose histogenesis is disputed. Many cases referred to us had been misdiagnosed.

Objective: Our purpose was to clarify the differential diagnosis and differentiation of MAC.

Congenital absence of dermatoglyphs.

Congenital absence or unusual patterns of human dermatoglyphs (fingerprints) occur in several syndromes that are rare and poorly understood. The abnormalities of dermatoglyphs fall into four categories: complete absence, ridge hypoplasia, ridge dissociation, and ridges-off-the-end. Complete congenital absence of ridges is an exceedingly rare syndrome that consists of neonatal blisters and milia, adult traumatic blistering and fissuring, absence of sweating, contracture of digits, and absence of dermatoglyphs on the hands and feet.

Nerve sheath myxoma (neurothekeoma) of the skin: light microscopic and immunohistochemical reappraisal of the cellular variant.

Nerve sheath myxoma (NSM) is a rare cutaneous neoplasm, the histogenesis of which is controversial. Fifteen cases of NSM were studied by routine light microscopy and with a broad panel of immunohistochemical stains. NSM were classified into three groups based on cellularity, mucin content and growth pattern.

Nodular lesions of erythema elevatum diutinum in patients infected with the human immunodeficiency virus.

Background: Erythema elevatum diutinum (EED) is a rare, chronic form of cutaneous vasculitis that can result in fibrosis. Four patients infected with the human immunodeficiency virus (HIV) had unusual nodular lesions of EED.

Objective: Our purpose was to document the occurrence of these lesions in HIV-infected patients and to characterize the histopathologic and immunophenotypic features of nodular EED.

Caterpillar bodies: distinctive, basement membrane-containing structures in blisters of porphyria.

In a previous study, we reported on the observation of a relatively specific, linear body in the roofs of bullae from cases of porphyria cutanea tarda. In the present study, we expand on these observations to show the presence of these bodies in lesions of pseudoporphyria cutanea tarda and erythropoietic protoporphyria. Furthermore, we have applied immunoperoxidase techniques using antibodies to type IV collagen and laminin to show that they are composed of basement membrane material.

The epidemiology of bacillary angiomatosis and bacillary peliosis.

Objective: To determine environmental risk factors for bacillary angiomatosis-bacillary peliosis (BAP), and to confirm infection with Rochalimaea species.

Design: Case-control study.

Setting: Community and university hospitals and clinics.

Lymphomatoid papulosis followed by Hodgkin's lymphoma. Differential response to therapy.

Background: The association of lymphomatoid papulosis (LyP) with Hodgkin's lymphoma or other lymphomas is well recognized. However, the issue as to whether this represents an independent association or a transformation of one proliferative process to the other remains unresolved.

Observation: A woman with LyP subsequently developed Hodgkin's lymphoma.

Isolation of Rochalimaea species from cutaneous and osseous lesions of bacillary angiomatosis.

Background: Bacillary angiomatosis is characterized by vascular lesions, which occur usually in patients infected with the human immunodeficiency virus (HIV). A newly described gram-negative organism, Rochalimaea henselae, has been associated with cutaneous bacillary angiomatosis, but no organism has been isolated and cultivated directly from cutaneous tissue.

Methods: We used two methods to isolate the infecting bacterium from four HIV-infected patients with cutaneous lesions suggestive of bacillary angiomatosis: cultivation with eukaryotic tissue-culture monolayers and direct plating of homogenized tissue onto agar.

Angiomatosis with luminal cryoprotein deposition.

Background: Angioendotheliomatosis has recently been separated into two types. Malignant angioendotheliomatosis is a lymphoma in which the neoplastic cells accumulate in vascular lumens. Reactive angioendotheliomatosis is a proliferation of capillaries that is less well characterized.

Dowling-Degos' disease mimicking chloracne.

We describe a patient with clinical features that resembled severe chloracne; however, histopathologic findings revealed a reticulated pigmented anomaly. Innumerable comedones, many cysts, acneiform scarring, and flexural and facial pigmentation were noted in this patient, who is a machinist. A serum test for polychlorinated biphenyl was negative, which eliminated a diagnosis of chloracne.