Reticulohistiocytoma and multicentric reticulohistiocytosis. Histopathologic and immunophenotypic distinct entities

The clinicopathological and immunohistochemical features of four patients with systemic multicentric reticulohistiocytosis (MR) were compared with five cases of solitary and one case of multiple reticulohistiocytoma (RH), which were confined to the skin only. The MR cases mostly affected the limbs of older women, while RH affected young male adults without preference to site. Characteristically, both entities consisted of oncocytic mononuclear histiocytes (with granular eosinophilic cytoplasm similar to oncocytic thyroid cells) and multinucleated histiocytes with a ground-glass appearance, which appeared to be much larger (> 200 microns) and bizarre in cases of RH compared with cases of MR (50-100 microns). In RH a variable number of vacuolated, spindle-shaped, and xanthomatized mononuclear histiocytes were also present. Immunohistochemical profiles showed positivity of mononuclear histiocytes with HHF35, factor XIIIa, and LN3 (HLA-DR), with a variable number of multinucleated histiocytes in RH showing binding with peanut agglutinin. In mono- and multinucleated histiocytes in both entities macrophage markers KP1 (CD68), KiM1P, HAM56, lysozyme, and alpha 1-antitrypsin were positive. However, macrophage markers MAC387 (L1 antigen) and Leu-M1 (CD15) were negative. Vimentin was universally positive in both conditions, with all other markers (S100, desmin, smooth muscle-specific actin, and QBEnd 10 [CD34]) negative. This study shows that histology supplemented by immunocytochemistry delineates MR from RH and immunohistochemical profiles indicate a cell lineage relationship between RH and adult xanthogranuloma.

Heat shock protein 65 immunoreactivity in experimentally induced polymorphic light eruption

The expression of 65 kiloDalton heat shock protein (HSP65) immunoreactivity of skin biopsies from experimentally induced polymorphic light eruption (PLE) lesions was studied, to investigate its possible role as a photo-induced antigen responsible for precipitating lesions. In each subject the 24-h minimal erythema dose of solar simulated radiation was determined and an area of skin previously affected by PLE subjected to 70% of the minimal erythema dose in order to induce PLE lesions. The irradiated areas were sequentially biopsied between 0 and 6 days. ML-30, a monoclonal antibody which recognises heat shock protein 65, was used to label the sections by means of an indirect immunoperoxidase technique. In PLE patients clinical inflammation was noted by 5 h post-irradiation, with subsequent evolution of PLE-like lesions; these were still present at 6 days. Increased ML-30 antibody labelling in epidermal keratinocyte and endothelial cell cytoplasm was recognisable from 1 h post-irradiation, and in dermal dendritic cells from 5 h sustained through to 6 days. In normal subjects neither clinical nor histological features of inflammation were noted after irradiation, nor any increase in HSP65 labelling.

Childhood Jessner's lymphocytic infiltrate of the skin

We report a case of Jessner's lymphocytic infiltrate of the skin in an 11-year-old boy. This benign lymphocytic infiltrate was originally described in 1953, and classically occurs in middle-aged men. Its occurrence in children appears to be very rare, and there are only two other case reports in the literature.

Disseminated eruptive clear cell acanthoma--a case report with review of the literature

Clear cell acanthoma (CCA) is a benign epidermal tumour with distinctive and uniform clinical and histological features. Although solitary lesions are the rule, some cases of multiple CCA, rarely with more than 10 lesions, have been previously reported. Only 22 cases of multiple CCA have been described in the English literature to date. A healthy 32-year-old woman is reported, with approximately 400 asymptomatic rounded papules, on the upper and lower extremities. Multiple skin biopsies showed the typical histological pictures of CCA. This case appears unusual because of the presence of numerous lesions scattered on the upper and lower extremities. For this reason it could be classified as disseminated eruptive CCA.

Desmoplastic malignant melanoma. An immunocytochemical study of 25 cases

Using a panel of seven cell markers, we studied the value of immunocytochemical labelling in the histological diagnosis of desmoplastic malignant melanoma. Sections from routine formalin-fixed tissue of 45 surgical specimens were obtained from 25 cases of malignant melanoma that showed well-marked desmoplastic or neurotropic features. Routinely stained sections (Haematoxylin- and -eosin and melanin stains) were compared with the following panel of seven antibodies: S-100, neuron-specific enolase (NSE), vimentin, factor XIIIa (FXIIIa), desmin and the newer, supposedly more specific antimelanoma antibodies HMB45 and NKIC3. S-100 and NSE were the most sensitive antibodies for desmoplastic malignant melanoma with strong labelling of spindle cells in most cases. In contrast, results for NKIC3 were more variable; results were negative in nearly half the tumours, but strong labelling was seen in six cases (27%). Positive labelling for HMB45 was noted in five tumours (22%); it was mostly confined to small groups of cells in the superficial part of the lesions. Tumour spindle cells were negative for FXIIIa in all cases; there was no increase in the number of positive dermal dendritic cells compared to conventional and spindle cell melanoma. All tumours were desmin-negative, but most were vimentin-positive. Our findings indicate that immunocytochemistry is of less value in the diagnosis of desmoplastic malignant melanoma that it is with other types of malignant melanoma. However, positive or negative labelling for S-100 protein and NSE is useful for suggesting or excluding a diagnosis of desmoplastic malignant melanoma; neither marker is specific and, in particular, positive labelling is also found in most neurofibromas and benign cellular naevi.(ABSTRACT TRUNCATED AT 250 WORDS)

Juvenile and adult xanthogranuloma. A histological and immunohistochemical comparison

Thirteen cases of juvenile xanthogranuloma (JXG) and 13 cases of adult-type xanthogranuloma (AXG) were compared at the light and immunohistochemical levels. Histologically, four main cell types (vacuolated, xanthomatized, spindle-shaped, and "oncocytic") were seen in variable proportions (from monomorphous to mixed variants) with different types of giant cells (nonspecific, foreign body, Touton, and "ground-glass"). Giant cells were more prominent in AXG than in JXG; oncocytic cells (characterized by an eosinophilic, slightly granular cytoplasm similar to thyroid oncocytic cells) and mostly periodic acid-Schiff (PAS) negative giant cells with a ground-glass appearance (6 of 26) were not observed in classic JXG (i.e., occurring in children < 2 years old). Immunohistochemically, JXG and AXG gave similar results: most xanthogranuloma cells labeled strongly with KiM1P and vimentin, while HHF35 and HAM56 stained less intensively. Factor-XIIIa (FXIIIa), KP1 (CD68), and HAM56 stained mostly in the periphery of the lesions. Some markers gave variable results: peanut agglutinin (PA), 60%; alpha-1-antitrypsin, 50%; lysozyme, 25%; LN3 (HLA-DR), < 10% of cells positive. Others were negative: S-100, MAC387 (L1 antigen), LeuM1 (CD15), desmin, smooth muscle-specific actin, and QBEND10 (CD34). This profile helps to delineate xanthogranuloma from histological stimulants such as dermatofibroma (which is FXIIIa+, LN3+, KP1-, and PA-) and multicentric reticulohistiocytosis (which is FXIIIa-, KP1+, PA-, and HHF35-).

Superficial granulomatous pyoderma. A report of two cases

We report two cases of superficial granulomatous pyoderma (SGP). Unlike classical pyoderma gangrenosum this variant is characterized by a benign course, superficial ulceration and a granulomatous infiltrate. Although our cases share the typical features of SGP, they are noteworthy in that one had the disease for 18 years, and the other had concomitant sarcoidosis.

Comparative study of the efficacy and safety of loratadine syrup and terfenadine suspension in the treatment of chronic allergic skin diseases in a pediatric population

The safety and efficacy of loratadine (Sch 29851, CAS 79794-75-5) syrup (5 or 10 mg QD) was compared to terfenadine (CAS 50679-08-8) suspension (30 mg b.i.d.) in a randomized, third party blind, parallel-group, multicenter trial. Two hundred thirty-six children ages 6-12 years, with chronic allergic skin disorders were treated for 14 days. The predominant skin condition was atrophic dermatitis (88% of the efficacy population). Evaluation of efficacy was based on investigator and patient assessment of symptoms, overall condition of the disease, and therapeutic response to treatment. After 7 and 14 days of treatment, and in the endpoint analysis (last valid study visit for all patients) the decreases from baseline in mean total sign/symptom scores, and all individual symptoms, did not differ significantly (p > 0.05) between treatments. Itching improved 54% in the loratadine group and 58% in the terfenadine group in the endpoint analysis. Forty-five percent of patients treated with loratadine and 46% of terfenadine-treated patients treated had complete or marked relief of their symptoms at endpoint. The efficacy of loratadine increased during the study, suggesting that patients did not develop tolerance to the medication over the 14-day course of therapy. Mild to moderate treatment-related adverse experiences were reported in 7/113 patients (6%) treated with loratadine and 11/119 patients (9%) treated with terfenadine. Single daily doses of 5 mg or 10 mg loratadine syrup were comparable to terfenadine suspension 30 mg twice daily for improving the symptoms of chronic allergic skin disorders in children. Loratadine was safe and well tolerated.

UV-induced colloid milium

A 39-year-old woman is reported who developed numerous confluent yellowish semitranslucent papules of the face over 8 months. The patient habitually exposed herself to UVA-radiation twice a week for 7 years for aesthetic reasons. Histological, histochemical and immunohistochemical examinations were consistent with the diagnosis of adult colloid milium. A review of the literature is discussed. This case emphasizes the close relationship between long-term sun exposure, solar elastosis and adult colloid milium.

Atypical Nekam's disease--keratosis lichenoides chronica associated with porokeratotic histology and amyloidosis

A patient with atypical Nekam's disease is described. Although the histological appearances were lichenoid, the presence of porokeratosis and amyloid deposition, previously reported in this condition, argue against the view that Nekam's disease is a subset of lichen planus.

Bacillary epithelioid angiomatosis in acquired immunodeficiency syndrome (AIDS)--clinicopathological and ultrastructural study of a case with a review of the literature

Bacillary epithelioid angiomatosis (BEA) is a rare cutaneous disorder usually affecting patients with human immunodeficiency virus (HIV) infection often misdiagnosed as a vascular tumour. We describe a 51-year-old, HIV-positive, Caucasian, homosexual male who developed scattered papulo-nodular lesions with clinicopathological and ultrastructural features of BEA. He had a dramatic therapeutic response to systemic antibiotics. There has been a lack of such reports in the European literature. The differential diagnosis is discussed and a brief review of the English literature to date is included.

The role of factor XIIIa-positive dermal dendrocytes in HIV-1-positive psoriatics

Factor XIIIa-positive dermal dendrocytes (FXIIIa+ dd) may have an important role in the pathogenesis of psoriasis, in that their numbers are increased in lesional skin compared with non-lesional skin. Moreover, in AIDS-associated Kaposi's sarcoma the number of these cells is also increased, in comparison with the classical type of Kaposi's sarcoma. In addition, patients suffering from HIV-1 infection may develop severe psoriasis. The aim of this study was to examine the distribution of FXIIIa+ dd in lesional and non-lesional skin from seven psoriatic patients with positive HIV-1 serology, and compare the results with age-, sex-, and site-matched HIV-1-negative psoriatic patients. In both patient groups there was an increase of FXIIIa+ dd in the papillary dermis in lesional skin, compared with non-lesional skin (HIV+ [P = 0.007]; HIV- [P = 0.0006]). Positive cells were also observed within the epidermis in lesional skin in both groups. However, there was no significant difference between HIV-1+ and HIV-1- groups in the number of FXIIIa+ dd in the epidermis and dermis (P > 0.05). These findings suggest that, if FXIIIa+ dd do have a role in psoriasis, deterioration of this condition in HIV-1+ patients is not due to proliferation of dermal dendrocytes.

Histologic and immunohistochemical study comparing xanthoma disseminatum and histiocytosis X

BACKGROUND AND DESIGN

As xanthoma disseminatum and histiocytosis X share clinicopathologic features, difficulties in diagnosis can arise. The use of immunocytochemical markers for S100 protein, factor XIIIa, lysozyme, alpha 1-antitrypsin, for adherence of peanut agglutinin and of antibodies LN3 (HLA-DR), Leu-M1 (CD15), QBEnd/10 (CD34), MAC 387, and KP1 (CD68) as an aid to conventional histology has been studied in routinely fixed skin biopsy specimens from seven patients with xanthoma disseminatum and 12 patients with histiocytosis X.

RESULTS

Typically xanthoma disseminatum occurs in discrete foci below an intact epidermis with individual cells set within a delicate fibrillary connective tissue stroma. In contrast, histiocytosis X usually occurs as a diffuse lichenoid infiltrate that can extend to deeper tissues. Epidermal invasion is common and the cells tend to lie free separated by edema fluid. Characteristic histiocytosis X cells are ovoid with an indented or kidney-shaped nucleus that occupies half or more of the cell. Xanthoma disseminatum cells differ in showing irregular scalloped borders, a more extensive cytoplasm, and an ovoid vesicular nucleus. Most xanthoma disseminatum cells labeled strongly for factor XIIIa and with KP1; a few cells labeled only weakly with peanut agglutinin. In contrast, most histiocytosis X cells labeled for S100 protein and with LN3 and peanut agglutinin. All the other markers remained negative in both conditions and were thus noncontributory for differentiating xanthoma disseminatum from histiocytosis X.

CONCLUSIONS

We conclude that the differences in labeling patterns are a useful aid to histologic diagnosis of histiocytosis X and xanthoma disseminatum and they also reflect their separate histiogenesis.

Granulomatous slack skin: a clinicopathological and immunohistochemical study of three cases

Three cases of granulomatous slack skin (GSS), a rare variant of T-cell lymphoma, are reported. Immunohistochemical studies using a panel of 16 antibodies were carried out on both frozen tissue and tissue embedded in paraffin wax to characterize the infiltrate. A routine immunoperoxidase technique was used to identify T cells (UCHL1, CD45R0), B cells (L26, 4KB5 [CD45R]), S100 protein-positive cells, monocytes/macrophages (Mac-387, KP1 [CD68]), and dermal dendrocytes (factor XIIIa) in paraffin sections. A close association was found between UCHL1-positive T cells and KP1-positive giant cells. A number of S100-positive cells and factor XIIIa-positive cells were present in the infiltrate from all three patients. The lymphocytes in two of the patients were predominantly of the helper T-cell phenotype. Giant cells from all three patients stained with KP1 (CD68) and Leu M3 (CD14). These studies confirm that the infiltrate in GSS is predominantly a T-cell disorder associated with monocyte-derived cells rather than with resident dendritic macrophages.

Systemic lupus erythematosus presenting with 'rheumatoid nodules'

A patient with systemic lupus erythematosus who presented with subcutaneous nodules over the flexor aspect of the fingers in association with arthritis and Raynaud's phenomenon is described. Histopathological examination of the nodules showed appearances consistent with rheumatoid nodules. Further investigations revealed leucopenia and circulating anti-nuclear antibody but negative rheumatoid factor. Immunofluorescence studies of normal non-light exposed skin showed the presence of IgM deposits at the dermo-epidermal junction consistent with systemic lupus erythematosus. The nodules almost disappeared following treatment with hydroxychloroquine. Rheumatoid-like nodules have been reported in systemic lupus erythematosus, although rarely. However, the distribution of the nodules and the patient's clinical course differ from the few cases previously reported in the literature.

White fibrous papulosis of the neck

We report a case of white fibrous papulosis of the neck in a 70-year-old Iranian woman. To date this recently reported entity has only been described in Japanese patients. This asymptomatic eruption characteristically affects the posterior neck. The pale papules are round to oval 2-3 mm in diameter, and not follicular. Histology shows thickened collagen bundles in the superficial and mid-dermis with a normal elastic pattern.

The effect of capsaicin application on mast cells in normal human skin

Peptides released from sensory nerves during an axon reflex are thought to cause mast cell degranulation, histamine (Hi) release and Hi-induced vasodilatation leading to the flare of the triple response. Capsaicin stimulates peptide release from sensory neurones and causes flare in vivo but does not cause Hi release from mast cells in vitro. The effects of capsaicin on mast cell degranulation in human skin in vivo has been studied by histological examination of skin biopsies after topical capsicin (1%) treatment of stratum corneum-denuded forearm in four volunteers. The results show a significant reduction in the visible numbers of mast cells and the appearance of degranulated mast cells ghosts in the skin six hours after capsaicin application. Since capsaicin itself does not release Hi from mast cells, these data suggest that capsaicin-induced release of peptides from neurones could cause mast cell degranulation.

The phenotypic heterogenicity of bullous ichthyosis--a case report of three family members

We present a family with an inherited disorder of cornification. The clinical features are much less severe and developed much later in life than is usual in bullous ichthyosis. Skin biopsy demonstrated epidermolytic hyperkeratosis, a feature typical of bullous ichthyosis. The family is reported both to highlight the wide interfamilial variation that may occur in this condition and the value of histology in classifying this form of ichthyosis.