Diane M. Hoss

Nevoid malignant melanoma: morphologic patterns and immunohistochemical reactivity

The term “nevoid malignant melanoma” (nevoid MM) is used here to describe rare nodular malignant melanomas that may escape detection in routine histological sections due to the lack of a prominent intraepidermal component, sharp lateral circumscription and evidence of partial maturation with descent in the dermis. Nevoid MM mimic ordinary compound or intradermal melanocytic nevi when the melanoma cells are small, or Spitzs nevi when the cells are large.

Herpes zoster in otherwise healthy children.

In normal infants and children, zoster can occur at any time after varicella or varicella vaccination. It is usually diagnosed clinically: a unilateral vesicular eruption following a dermatome or dermatomes. The incidence of zoster increases with age, although children who have had varicella during the first year of life (or in utero) are at increased risk of developing zoster. The incidence of zoster is less after varicella vaccination than after natural infection. Zoster in children is frequently mild, postzoster neuralgia rarely if ever occurs, and antiviral therapy is usually not needed. In a previously normal child with zoster, if the history and physical examination are normal, a laboratory search for occult immunodeficiency or malignancy is not needed. We present five cases of zoster in healthy children and review zoster in the pediatric age group.

Southern Tick-Associated Rash Illness (STARI) in the North: STARI Following a Tick Bite in Long Island, New York

The most common clinical manifestation of Lyme disease is the characteristic rash, erythema migrans (EM). In the 1980s EM-like eruptions were reported in Missouri and other southeastern states. The EM-like eruptions, which were of unknown etiology, often followed the bite of the Lone Star tick (Amblyomma americanum) and the rash is called STARI (southern tick-associated rash illness). Although the Lone Star tick is found in the Lyme disease-endemic areas of New England and Mid-Atlantic regions of the United States, STARI has been reported only once from the Northeast and Mid-Atlantic regions. We report a child from Connecticut who visited Long Island, New York, and developed a rash that was thought to be EM. Because the patient failed to respond to antibiotics used to treat Lyme disease, an investigation ensued, and the diagnosis of STARI was established.

Infantile generalized pustular psoriasis associated with lytic lesions of the bone

Abstract: Generalized pustular psoriasis is rare in children, especially in those less than 1 year of age. Lytic lesions of the bone have been reported in children with psoriasis, but are rare. We describe an infant with the clinical and histopathologic features of generalized pustular psoriasis that began in the first few weeks of life. In addition, this patient had sterile lytic lesions of the bone. Despite significant improvement In the bone lesions, his skin condition was resistant to therapy.

Atypical melanocytic lesions in epidermolysis bullosa

We report a 6‐year‐old female with recessive dystrophic epidermolysis bullosa (RDEB) who presented with a very large acquired melanocytic lesion. The lesion demonstrated many features both clinically and histologically that made the distinction from malignant melanoma difficult. The pathogenesis of this lesion and other unusual melanocytic lesions seen in the setting of acute and chronic blistering disorders seems related to repeated episodes of disruption of the dermal‐epidermal junction.

Histopathology of an adverse reaction to a eutectic mixture of the local anesthetics lidocaine and prilocaine.

A unique hislopathologic reaction to the topical application of a eutectic mixture of the local anesthetics lidocaine and prilocaine (EMLA), used for topical anesthesia prior to biopsy in two children is described. Standard application of EMLA cream under occlusion for 1 h was given to both patients. The biopsies in both cases demonstrate focal vacuolization of the upper spinous and granular layers. The epidermis was locally separated from the dermis in areas of basal vacuolar alteration. Electron microscopy performed in one case demonstrated the dermal‐epidermal cleft to be secondary to alteration of the basal cells with condensation of the cytoplasm and cytologic degeneration similar to that seen in epidermolysis bullosa simplex.

TREATMENT-RESISTANT PEMPHIGUS VEGETANS OF THE SCALP

In 1989, a 46-year-old man presented with a 1-montb bistory of vegetating plaques of tbe axillae and inguinal folds (Fig. 1). The oral mucosa was not involved. Tbe clinical diagnosis of pempbigus vegetans was confirmed bistologically by tbe presence of focal acantbolysis and eosinopbilic spongiosis and by intercellular staining on direct immunofluorescence. Tbe patients disease was well-controlled witb azathioprine and alternate day prednisone. Occasional flares were managed witb brief periods of daily prednisone. In 1992, on examination tbe patient was noted to bave postinflammatory byperpigmentation of tbe axillae and groin and a 3-cm fluctuant nodule of tbe vertex (Fig. 2). Tbe presence of long-standing onycbomycosis of the fingernails suggested, tbat tbe differential diagnosis include pempbigus vegetans versus tinea capitis witb kerion formation. A puncb biopsy of tbe nodule was unsuccessful because of marked friability. Fungal culture of friable tissue and surrounding bairs was obtained and empiric tberapy witb griseofulvin and prednisone, 60 mg daily, was initiated. Fungal cultures were negative, and there was no response to tberapy. Two montbs later, the patient developed periorbltal edema and pyoderma tbrougbout the scalp. A biopsy at tbis time was successful. A diagnosis consistent witb pempbigus vegetans was made. Tberapy with intravenous cefazolin and local measures, including wet dressings and keratolytic shampoo, led to resolution of the edema and decrease in the size of the scalp nodule; however, attempts to taper prednisone to alternate day therapy was unsuccessful despite increasing tbe dose of azathioprine to 50 mg twice daily and periodic intralesional (it) corticosteroid injections of the nodule. Discontinuation of azathioprine and initiation of dapsone 100 mg daily was only modestly beneficial. The increasing size of the nodule to 6 cm in diameter prompted a 5-day course of intravenous methylprednisolone therapy, 1 g daily. The scalp was essentially clear after pulse steroid tberapy, but tbe nodule redeveloped several weeks later, despite continued alternate day steroids and dapsone. A trial of daily prednisone, discontinuation of dapsone, and initiation of methotrexate 20 mg weekly, dicloxacillin 250 mg four times daily for 1 montb, and intermittent IL steroids

Melanoma on the move: The progression of melanoma: Novel concepts with histologic correlates

Careful observation and pattern recognition is the realm of the dermatopathologist. Although specific criteria have been described that define the histologic diagnosis of melanoma, morphologic and architectural variations have been observed for this tumor. And while the immunohistochemical profile of melanoma is well characterized, some melanomas exhibit immunophenotypic aberrations not typical of melanocytic differentiation. These findings can make the microscopic diagnosis of melanoma difficult. In this review article, we have assembled some of the recent advances in melanoma research that challenge the traditional models of melanoma pathogenesis and progression. We describe concepts that are associated with changes identifiable under light microscopy, which may explain some of the variable histologic and aberrant immunohistochemical profiles of melanoma. These advances are still the subject of active investigation and are best viewed as ‘‘works in progress’’ rather than widely accepted principles.

Prominent papillary dermal edema in dermatophytosis (tinea corporis).

Background: Commonly described histologic ‘clues’ to the diagnosis of dermatophytosis include neutrophils in the stratum corneum and/or epidermis, compact orthokeratosis and identification of fungal hyphae between two zones of cornified cells. Prominent (striking) papillary dermal edema (PPDE) is not commonly reported with dermatophytosis (tinea corporis).

The sensitivity and specificity of "caterpillar bodies" in the differential diagnosis of subepidermal blistering disorders.

Caterpillar bodies are eosinophilic, elongated, segmented bodies located within the roofs of blisters and are considered to represent a specific histopathologic feature of porphyric bullous eruptions, including porphyria cutanea tarda and erythropoietic protoporphyria. The possibility that similar or identical bodies may be present in other disorders prompted further study exploring the specificity of caterpillar bodies in the differential diagnosis of subepidermal vesiculobullous disorders. Seventy-six cases exhibiting subepidermal clefting were reviewed by light microscopy. “Classic” caterpillar bodies were present in porphyria cutanea tarda (6 of 14) and 1 case representing either venous stasis-associated bulla or possibly bullosis diabeticorum. Caterpillar body-like clusters were present in porphyria cutanea tarda (5 of 14), erythropoietic protoporphyria (1 of 3), bullous pemphigoid (7of 24), and junctional or dystrophic epidermolysis bullosa (3 of 5). In some cases, classic caterpillar body and caterpillar body-like clusters coexisted in a blister roof. Caterpillar bodies or caterpillar body-like clusters were not identified in any cases of dermatitis herpetiformis, linear IgA bullous dermatosis, bullous erythema multiforme, epidermolysis bullosa acquisita, or wound-healing reactions. In contrast to caterpillar bodies, caterpillar body-like clusters were negative for PAS or Type IV collagen stains. In conclusion, caterpillar bodies appear to represent a specific feature of porphyria cutanea tarda (specificity, 98%) but were present in less than half of those cases in this study (sensitivity, 43%). Caterpillar body-like clusters are less specific and may be present in porphyria cutanea tarda, erythropoietic protoporphyria, pseudoporphyria, bullous pemphigoid, epidermolysis bullosa, and epidermolysis bullosa acquisita.