Kaposiform haemangioendothelioma in an adult: lack of response to topical sirolimus and response to radiotherapy.

Kaposiform haemangioendothelioma (KHE) is a rare, primarily paediatric tumour with only a handful of case reports in the adult population. Given the paucity of evidence, this article is important in raising awareness of radiotherapy as a suitable and effective treatment in the adult population with KHE and highlights the potential limitations of topical sirolimus in these tumours.

A quantitative approach to histopathological dissection of elastin-related disorders using multiphoton microscopy.

BACKGROUND: Multiphoton microscopy (MPM) is a novel imaging technology that has recently become applicable for diagnostic purposes. The use of (near) infrared light in MPM allows for deep tissue imaging. In addition, this modality exploits the autofluorescent nature of extracellular matrix fibres within the skin. OBJECTIVES: To quantitate the structure and abundance of elastic fibres in human dermis in three dimensions utilizing autofluorescent signals generated by MPM for the objective examination of elastin-related skin disorders. METHODS: Cross-sections of skin samples from elastin-related disorders were analysed by MPM and correlated to histopathology. In situ visualization of elastic fibres by MPM was conducted by en face imaging of ex vivo skin samples through the intact epidermis. Image analysis software was used to quantify elastic fibres in three dimensions. RESULTS: Based on the MPM-detected elastin-specific autofluorescence, we developed the Dermal Elastin Morphology Index (DEMI), calculated as the ratio of elastic fibre surface area and volume. This enabled objective three-dimensional quantification of elastic fibres. Quantitative scoring of sun-damaged skin using DEMI correlated with qualitative histopathological grading of the severity of solar elastosis. Furthermore, this approach was applied to changes in elastic fibre architecture in other disorders, such as pseudoxanthoma elasticum (PXE), PXE-like syndrome, elastofibroma, focal dermal elastosis, anetoderma, mid-dermal elastolysis and striae distensae. We imaged elastic fibres in intact ex vivo skin imaged en face through the epidermis, indicating that this approach could be used in vivo. CONCLUSIONS: MPM has the potential for noninvasive in vivo visualization of elastic fibres in the dermis with near histological resolution. DEMI allows objective assessment of elastic fibres to support diagnosis and monitoring of disease progress or therapy of elastin-related skin disorders.

Cutaneous manifestations of dabrafenib (GSK2118436): a selective inhibitor of mutant BRAF in patients with metastatic melanoma.

BACKGROUND: Inhibitors of mutant BRAF are emerging as standard of care in patients with metastatic melanoma carrying relevant oncogenic mutations. Cutaneous reactions are frequent and significant. We conducted a systematic prospective dermatological review of all patients enrolled at a single institution in the phase I/II clinical trial of the mutant BRAF inhibitor dabrafenib (GSK2118436). OBJECTIVES: To identify the cutaneous manifestations of the BRAF inhibitor dabrafenib; to form diagnostic criteria to standardize the diagnosis of verrucal keratotic squamoproliferative lesions; and to bring awareness to the medical community of the importance of dermatological assessment of patients taking dabrafenib. METHODS: Patients enrolled in the phase I/II trial (n = 43) were monitored for the development of new skin lesions. Each new lesion was photographed, a clinical diagnosis recorded and, where appropriate, a biopsy taken. Human papillomavirus (HPV) and p16 immunohistochemistry analyses were performed. RESULTS: The most frequently observed lesions were verrucal keratotic squamoproliferative lesions (49%), Grover's disease (27%) and reactive hyperkeratotic lesions on the soles, at points of friction (22%). Eighteen squamous cell carcinomas (SCCs) occurred in 20% of patients. Most SCCs appeared between weeks 6 and 24 following commencement of therapy on both sun-damaged and nonsun-damaged skin. All SCCs were well differentiated, five were of the keratoacanthoma type, and two were SCC in situ. Other lesions observed included seborrhoeic keratoses, epidermal cysts, acneiform eruptions, hair loss and changes in hair structure. HPV was negative in 15 of the 16 tissues studied and p16 expression was higher in SCCs compared with verrucal keratoses. CONCLUSIONS: Administration of the mutant BRAF inhibitor dabrafenib is associated with induction of keratinocytic proliferation, which in some cases develops features of low-grade malignancy. Highly oncogenic HPV infection is unlikely to be a contributor to the formation of SCCs or verrucal keratoses.

Seborrhoeic keratoses appearing in sites of previous psoriasis plaques during treatment with efalizumab.

A 56-year-old man with recalcitrant psoriasis was treated with efalizumab, resulting in complete clearing of his skin lesions. However, multiple brown patches and papules, in the exact distribution of the previous psoriasis plaques, appeared on his lower legs. The pathological diagnosis was seborrhoeic keratoses (SKs) with overlapping features of solar lentigo. A variety of cutaneous adverse events has been observed in patients with psoriasis treated with efalizumab. To our knowledge, appearance of SKs after such treatment has not previously been reported. This may be due to the clinical insignificance of these benign skin tumours. However, it may be speculated whether efalizumab has an unknown effect in triggering the development of SKs in patients with psoriasis, and if this could shed any light on the pathogenesis of SKs.

Treatment of large facial Bowen's disease: case report.

Bowen's disease (BD; squamous cell carcinoma in situ) is a common, persistent condition that can be related to chronic sun damage, and consequently, is usually located around the head and neck area and lower limbs. Bowen's disease can be treated with a variety of methods, including surgery or laser therapy, but large lesions tend to scar postexcision and hence are difficult to treat surgically. Here we present the case of a 75-year-old woman with a 20-year history of facial BD unabated by treatment with a variety of topical agents and cryotherapy. Application of imiquimod 5% cream on alternate nights for 6 weeks resulted in total clearance with no recurrence observed after 8 months.

Dowling-Degos disease--a heat aggravated variant.

A 22-year-old woman presented with a 5-year history of a micropapular eruption localized to the flexor aspect of her limbs as well as persistent reticulate pigmentation of her neck and upper chest resembling Darier's disease. The eruption was associated with pruritus that was precipitated by heat and was worse in summer. The axillae, groins and inframammary areas had multiple papules but lacked reticulate pigmentation. Multiple biopsies showed an epidermis with club- and antler-like rete ridges but no acantholysis or dyskeratosis. This distinct clinical presentation may represent an unusual heat aggravated variant of Dowling-Degos disease that clinically shares features with Darier's disease and transient acantholytic dermatosis.

Necrotizing infundibular crystalline folliculitis.

We describe a 22-year-old woman with a background of acne who developed multiple folliculocentric facial papules associated with sharply demarcated waxy, keratotic plugs. Multiple skin biopsies showed umbilicated craters that were filled with dispersed bundles of eosinophilic filaments embedded in a pale amorphous matrix forming a plug. The plugs bulged into the upper dermis. Serial sections showed vacuolar and filamentous destruction of the infundibular and adjacent perifollicular epithelium and a close relationship of the crystalline necrosis to follicles. Electron microscopy revealed that the filamentous bundles were tonofilaments. No fresh material was available for polarization and the paraffin sections failed to polarize. The clinical and pathological findings of the lesions in our patient were identical to those reported as a new perforating disorder with urate-like crystals. Our case indicates that the process may represent crystalline folliculocentric necrosis rather than a primary perforating disorder. The nature and basis of the crystals that have a urate-like appearance remain to be determined.

The application of a PCR technique for the detection of immunoglobulin heavy chain gene rearrangements in fresh or paraffin-embedded skin tissue.

Although detection of a clonal sequence of the heavy chain gene of immunoglobulin by the polymerase chain reaction (PCR) is frequently used to assess lymphoid infiltrates in skin biopsy specimens, there are no data on the sensitivity and specificity of this test in detecting clonal B cell populations. Having refined a PCR technique for the detection of immunoglobulin heavy chain (IgH) gene rearrangement in both fresh and formalin-fixed, paraffin-embedded skin samples, we undertook to define the role of this assay in the diagnostic setting. Thirty-one cases of cutaneous B cell lymphoma (CBCL), 19 cases of B cell pseudolymphoma (lymphocytoma cutis), 34 cases of benign lymphocytic infiltrates of the skin and one case of cutaneous T cell lymphoma (CTCL) were studied using the polymerase chain reaction assay. All biopsies were formalin-fixed, paraffin-embedded skin sections apart from 13 of the 31 CBCL specimens which were fresh skin specimens. DNA from the framework region 3 (FR3) sequence of the IgH genes was amplified to ascertain the presence of a clonal IgH gene rearrangement. The findings were correlated with histological and immunophenotyping results on all samples. The assay performed with 73% sensitivity and 100% specificity, comparable to results obtained examining fresh lymphoid tissue specimens from patients with B cell tumours. The results indicate that this technique is a useful tool in the work up of suspected CBCL and in differentiating between CBCL and mixed lymphocytic infiltrates, a clearly important distinction with regards to prognosis and treatment.

Mid-dermal elastophagocytosis presenting as a persistent reticulate erythema.

Two men are presented with a widespread persistent reticulate erythema concentrated within the chronically sun-damaged skin on their trunk. A fine papular element was present in one case and both lacked annular lesions. One patient was human immunodeficiency virus positive. Multiple skin biopsies showed an interstitial infiltrate of histiocytes containing multiple elastic fibres in the upper dermis. There was scant perivascular lymphocytic inflammation but no evident necrobiosis or palisaded granulomas seen typically with granuloma annulare. Elastic stains showed focal mid-dermal elastolysis. Diffuse reticulate erythema in sun-damaged skin may be a clinical marker for elastophagocytosis. This presentation differs from that previously described with actinic granuloma, diffuse granuloma annulare or the inflammatory phase of mid-dermal elastolysis and expands the clinical spectrum of this phenomenon.

Imiquimod 5% cream in the treatment of Bowen's disease.

BACKGROUND: Large-diameter lesions of Bowen's disease at sites such as the shin may be difficult to treat surgically and may require alternate treatment modalities. OBJECTIVE: We investigated whether imiquimod 5% cream, a topical immune response modifier that stimulates the production of interferon alfa and other cytokines, is an effective topical treatment for Bowen's disease. METHODS: This was a phase II, open-label study in 16 patients, treating a single biopsy-proven plaque of Bowen's disease that was 1 cm or larger in diameter, with once-daily self-application of imiquimod 5% cream for 16 weeks. A biopsy was performed on the treated area 6 weeks after the end of treatment, with patient follow-up at 3 and 6 months. Lymphocyte CD4/CD8 ratios were analyzed in pretreatment and posttreatment biopsy specimens by immunophenotyping the lymphocytic infiltrate. RESULTS: Sixteen patients with Bowen's disease lesions ranging from 1 to 5.4 cm in diameter (0.7-21.6 cm(2) in area) were treated. Fifteen of these lesions were on the legs, and one was on the shoulder. Fourteen of the 15 patients (93% per protocol analysis) had no residual tumor present in their 6-week posttreatment biopsy specimens. One patient died of unrelated intercurrent illness before a biopsy specimen could be obtained. The median CD4/CD8 lymphocyte ratio in pretreatment biopsy specimens was 2:1, and this was reversed to a median of 1:2.2 in the posttreatment specimens. Ten patients completed 16 weeks of treatment, but 6 patients ceased treatment early (between 4 and 8 weeks) because of local skin reactions. CONCLUSION: Imiquimod 5% cream appears to be an effective treatment for Bowen's disease on the lower limbs. The 93% positive treatment response in biopsy-proven cases (excludes patient who died from an intercurrent illness who did not undergo a posttreatment biopsy) compares favorably with other current treatment modalities. The dosing schedule and length of treatment for Bowen's disease require further evaluation.

Sarcoidosis with prominent giant cells.

A 31-year-old man presented with a widespread papular eruption and systemic symptoms including renal colic and decreased exercise tolerance. The combination of clinical features and laboratory investigations that revealed an elevated angiotensin converting enzyme level and hypercalcaemia enabled a diagnosis of sarcoidosis to be made. Multiple skin biopsies showed prominent Touton-like giant cells which delayed the diagnosis. Giant cells are frequently seen in sarcoidal granulomas but in some cases their prominence and Touton-like appearance may suggest alternative diagnoses such as xanthogranulomas.

Analysis of dendritic cell populations using a revised histological staging of morphoea.

BACKGROUND: Recent studies have suggested that dermal dendritic cells (DDCs) may play a part in maintaining the structure of the dermis and in dermal immune modulation. Alteration in the population of DDCs has been noted in localized and systemic scleroderma, particularly a decline in the number of CD34+ DDCs. Objectives To define the alteration of the DDC populations with respect to the histological stage of morphoea. METHODS: We examined 33 biopsies of morphoea, categorized into four histological stages, and examined the DDC population (CD34+ DDCs and factor XIIIa+ DDCs), the lymphocytic infiltrate, and tenascin (extracellular matrix glycoprotein) and transforming growth factor (TGF)-beta1 expression in each biopsy. RESULTS: As the dermis became less inflammatory and more sclerotic, there was a significant decline in the number of CD34+ DDCs and an increase in the number of factor XIIIa+ DDCs. The pan-T-cell infiltrate (UCHL-1/CD45RO) and tenascin deposition exhibited a similar pattern, with elevated expression in inflammatory stages and a decrease in expression as the dermis became sclerotic. TGF-beta1 was significantly elevated in three of the four histological stages of morphoea, in both the inflammatory and sclerotic stages. The proposed four-stage histological analysis of morphoea biopsies was a useful basis for studying dendritic cells and mediators in cutaneous sclerosis. CONCLUSIONS: Our study indicates that there is a reciprocal relationship between CD34+ DDCs and factor XIIIa+ DDCs in morphoea that correlates with the relative degrees of inflammation and sclerosis.

Lipid and giant cell poor necrobiotic xanthogranuloma.

An 88-year-old man over a 7-month period developed multiple yellow firm focally ulcerative papules and nodules over his face, neck and forearms. Seven skin biopsies showed a diffuse infiltrate of epithelioid histiocytes associated with areas of necrosis with neutrophilia. Two biopsies showed xanthogranulomatous foci, but cholesterol clefts, prominent giant cells or lymphoid aggregates were not evident. Necrosis with leukocytoclastic debris overshadowed the presence of hyaline necrobiosis. Ultrastructural examination and oil red-o stains on frozen sections revealed focal lipid vacuoles within histiocytes. A paraprotein was detected in the patient's serum. This presentation may represent a lipid and giant cell poor variant of necrobiotic xanthogranuloma (NXG) and may potentially lead to a delay in diagnosis.

Defining lymphocytic vasculitis.

Vasculitis can be defined as vascular inflammation which is usually immune mediated, leading to structural and functional damage to the vessel wall. Our concept of vasculitis has been built around the events surrounding immune-complex-triggered leukocytoclastic vasculitis, while the role of lymphocyte mediated vasculitis remains largely undefined. This may be due to maintaining a stereotypic image of lymphocytic vasculitis as one associated with vascular necrosis, fibrin deposition and haemorrhage and merely substituting lymphocytes for neutrophils. Our understanding of lymphocytic vasculitis may be advanced by identifying the clinical settings in which such reactions may occur, such as autoimmune skin diseases sharing features with graft vs host disease, as well as recognizing that lymphocyte mediated inflammation may lead to a morphologically distinct group of vasculitides, apart from those associated with angiodestruction. Lymphocytic endovasculitis, lymphocytic lichenoid vasculitis and granulomatous vasculitis are potential examples of lymphocytic vasculitis that differ from the histological pattern seen in association with immune complex leukocytoclastic vasculitis. Ultimately, the proof that these vasculitides are examples of lymphocytic vasculitis will rest on new techniques emerging in molecular pathology that have the capacity of analysing the immunological events beyond the current limitations posed by routine histopathology.

Folliculotropic T-cell lymphocytosis (mucin-poor follicular mucinosis).

A 48-year-old man presented with multiple asymptomatic patches of hair loss over his trunk and limbs associated with focal keratotic follicular plugs. Multiple skin biopsies showed a panfollicular lymphocytic infiltrate associated with follicular hyperkeratinization, minimal follicular spongiosis, focal basaloid follicular hyperplasia but no overt follicular mucinosis. The lymphocytes were small and there was no atypia. Immunoperoxidase stains showed that the follicular lymphocytes were T cells and predominantly CD4 positive with HLADr (LN3) expressed on their surface. There were insufficient clinical or histopathological features to make a diagnosis of folliculotropic T-cell lymphoma. This case currently may be classified best as folliculotropic T-cell lymphocytosis and may represent a mucin-poor counterpart of follicular mucinosis. Such cases may pursue an indolent course or may evolve to folliculotropic T-cell lymphoma, mycosis fungoides or anaplastic lymphoma. The term folliculotropic T-cell lymphocytosis may be useful for similar cases lacking clinical or histological criteria for lymphoma and lacking follicular mucinosis.