Comparative histochemical study of Bowen's disease and actinic keratosis: preserved normal basal cells in Bowen's disease.

The degree of DNA-instability as revealed by immunohistochemical staining with anti-cytidine antibody after acid hydrolysis (DNA-instability test) has been recently used as a marker of malignancy. This technique was applied to examine 17 skin tissue samples of Bowen's disease, 47 of actinic keratosis, 15 of squamous cell carcinoma, 5 of seborrheic keratosis, and 10 of normal skin. All benign neoplastic cells of seborrheic keratosis and normal epidermal cells were negative. On the other hand, all cancer cells were positive with the DNA-instability test, indicating their malignancy, but all basal cells in Bowen's disease were completely negative. Compatible with this result, the basal cells in Bowen's disease were characteristically normal as evident in other histochemical examinations. Thus, they were negative with p53 immunohistochemistry, with normal signals of chromosome 17 in situ hybridisation and argyrophilic nucleolar organiser region, and showed slightly enhanced proliferative activity as revealed by proliferating cell nuclear antigen immunohistochemistry. Immunohistochemical staining with 34 beta E12 (monoclonal antibody against cytokeratins 1, 5, 10, and 14), which stains all normal epidermal keratinocytes including basal cells, showed that only the basal cells of Bowen's disease stained strongly and homogeneously, while all cancer cells in the upper layers of Bowen's disease and all layers of actinic keratosis were only sporadically or weakly stained. Staining with 34 beta B4 (monoclonal antibody against cytokeratin 1), which recognises the whole epidermis except for the basal layer in the normal epidermis, showed that the basal cells in the Bowen's disease were completely negative, and lower layer cells in the actinic keratosis and upper layer cells in Bowen's disease were only sporadically stained positive, although the superficial layer cells in actinic keratosis stained strongly and homogeneously. Our findings clearly indicate that the basal cells in Bowen's disease are normal. In support of this conclusion, the same cells showed normal morphology on electron microscopy with preserved basement membrane, although the latter was often damaged in actinic keratosis.

Hair follicle nevus occurring in frontonasal dysplasia: an electron microscopic observation.

We report a rare hair follicle nevus that occurred in a three-month-old Japanese boy with mild frontonasal dysplasia. It had been present since birth. Histologically, numerous tiny vellus hair follicles were found within the dermis. The constituent cells of these follicles showed the features of follicular germ cells under the electron microscope. The fibroblasts around the follicles were active and merged with the colloid substance. Many myofibroblasts were found in a collagenous stroma in the atrophic lesion of the frontonasal dysplasia.

Volar melanotic macules in a Japanese man with histopathological postinflammatory pigmentation: the volar counterpart of mucosal melanotic macules.

BACKGROUND: Volar melanotic macules are asymptomatic light-brown or tannish-grey macules usually found on the palms and/or soles of blacks, although they have also been reported on the volar surfaces of whites. Similar lesions have not been reported before in Japanese people. Since the cause is as yet unknown, it remains to be discussed whether they are a distinct entity. METHODS: In this report, a 52-year-old Japanese man with volar melanotic macules is reported with the clinical and histopathological findings. RESULTS: A 52-year-old Japanese man presented with many light-brown macules on his bilateral soles. He had a 20-year history of tinea pedis. Histopathological examination revealed melanophages and inflammatory infiltrates in the superficial dermis. There was a slight increase in melanin granules around the acrosyringium. Fontana-Masson stain revealed a slight increase in melanin granules in the basal layer including the acrosyringium and superficial dermis. These changes corresponded with postinflammatory pigmentation. CONCLUSIONS: This is the first report of volar melanotic macules in Japanese people. We suggest that volar melanotic macules is not an independent entity but a clinicopathological one that includes postinflammatory pigmentation, and that the condition is the volar counterpart of mucosal melanotic macules.

Expression of granulocyte colony-stimulating factor and its receptor in epithelial skin tumors.

Granulocyte colony-stimulating factor receptors (G-CSFR) have been observed on the surface of not only hematopoietic cells but also several cancer cells. In the present study, we investigated the expression of G-CSFR or G-CSF in epithelial skin tumors by immunohistochemical staining. The assessments were defined by the percentage of G-CSFR or G-CSF positive cells and expressed as G-CSFR and G-CSF scores. The G-CSFR score in SCC (77.6+/-20.0%) was significantly higher than that in Bowen's disease (BD) (51.0+/-35.6%), actinic keratosis (AK) (49.3+/-34.6%) or normal skin (30.0+/-32.1%) (P=0.0004, P=0.0003, P<0.0001, respectively). The mean G-CSF score in SCC (56.7+/-27.4%) or in BD (44.1+/-31.4%) was higher than that in normal skin (24.9+/-25.8%) (P=0.0075, P<0.001, respectively). G-CSF expression in AK (29.8+/-31.2%) was lower than that in SCC (P=0.0037). There was significant positive correlation between the G-CSFR score and the G-CSF score (gamma=0.274, P=0.0107) in skin tumors. These findings suggested that the assessment of G-CSFR expression might be associated with carcinogenesis of skin tumors.

Sub-populations of melanocytes in pigmented basal cell carcinoma: a quantitative, ultrastructural investigation.

BACKGROUND: Pigmentation is a characteristic clinical feature of basal cell carcinomas (BCCs) in Japanese patients. The pathogenesis of melanin pigment in pigmented BCCs is poorly understood. METHODS: We have combined the techniques of morphometric analysis and electron microscopy to assess accurately the morphologic aspects of melanocytes that occurred in pigmented and non-pigmented areas of pigmented BCCs. RESULTS: In the pigmented areas melanocytes were not only located along the basal membrane but also interspersed between tumor cells in the central parts of the tumor nest, and had large and numerous dendrites. Those in a supra-basal location displayed some degree of degeneration due to mitochondrion and melanosome swelling. In the non-pigmented areas melanocytes were only basally located, showed fewer dendrites, and frequently showed abortive melanosomes. However, melanocytes in these two different portions were in the active state of melanogenesis and proliferation. Ultrastructural cytomorphometric analysis also showed significant differences in most of the nuclear and cell parameters including nuclear and cell area, the nuclear/cell area ratio, cell perimeter and cell form factor between these two types of melanocytes. Particularly melanocytes in the pigmented areas were twice the cell size of the latter. In addition, the melanosomes remained almost completely in the apoptotic tumor cells, and the phagocytosis of the melanosome-containing apoptotic cells by the neighboring tumor cells appeared to be followed by the formation of the melanosome complexes. CONCLUSIONS: These findings suggest that different populations of melanocytes are probably present in pigmented BCCs, and repeated cycles of phagocytosis of melanosome-containing apoptotic cells may represent the predominant way of forming large melanosome complexes. The present morphological observation and quantitative analysis provide a morphological basis for further studies to interpret other pathologic changes in pigmented BCCs.

Clonal evolution and progression of 20-methylcholanthrene-induced squamous cell carcinoma of mouse epidermis as revealed by DNA instability and other malignancy markers.

We examined the clonal evolution of skin malignant lesions by repeated topical applications of 20-methylcholanthrene (20-MC) to the skin, which induces hyperplastic epidermis, papillomatous lesion and invasive carcinoma in mice. The lesions were examined histologically and immunohistochemically with anti-single-stranded DNA after acid hydrolysis (DNA-instability test), p53, VEGF, DFF45, PCNA and AgNORs parameters analyses. Multiple clones with increased DNA instability comparable to that of invasive carcinoma were noted in early-stage (2-6 weeks) hyperplastic epidermis, and their number increased in middle (7-11 weeks), and late-stages (12-25 weeks) of hyperplastic epidermis, indicating that they belong to the malignancy category. All papillomatous lesions and invasive carcinomas showed a positive DNA-instability test. Positive immunostaining for various biomarkers and AgNORs parameters appeared in clones with a positive DNA-instability test in early-or middle-stage hyperplastic epidermis, and markedly increased in late-stage hyperplastic epidermis, papillomatous lesions and invasive carcinomas. The percentage of PCNA-positive vascular endothelial cells was significantly higher in VEGF-positive lesions with a positive DNA-instability test and became higher toward the late-stage of progression. Cut-woundings were made to papillomatous and invasive carcinoma lesions, and the regeneration activity of vascular endothelial cells was determined by using flash labeling with tritiated thymidine (3H-TdR). In small papillomatous lesions, vascular endothelial cells showed regenerative response, but the response was weak in large lesions. No such response was noted in invasive carcinomas; rather, cut-wounding induced collapse of blood vessels, which in turn induced massive coagulative necrosis of cancer cells. These responses can be interpreted to reflect exhausted vascular growth activity due to excessive stimulation by VEGF-overexpression, which was persistently seen from hyperplastic epidermis to invasive carcinoma.

A case of intravascular large B-cell lymphoma mimicking erythema nodosum: the importance of multiple skin biopsies.

BACKGROUND: Intravascular lymphoma is a rare disease characterized by the proliferation of neoplastic monuclear cells within the lumens of small blood vessels. The neoplastic cells are usually of B-cell origin, and rarely of T-cell or histiocytic origin. Although this clinicopathological entity of lymphoma has not been listed in general pathological classifications such as REAL classification or the Working Formulation, it is recently in the WHO classification scheme, which is essentially an updated REAL scheme, and the EORTC classification scheme. METHODS: In this report, a 62-year-old woman with intravascular large B-cell lymphoma was observed by clinical, histopathological, immunohistochemical and molecular methods. RESULTS: A 62-year-old woman presented with large erythematous macules on the bilateral thighs and lower legs. The lesions were accompanied with hard, tender, intradermal or subcutaneous nodules mimicking erythema nodosum. Histopathological examination in the first biopsy revealed non-specific panniculitis compatible with erythema nodosum. The second biopsy revealed emboli of atypical lymphocytes within many of the dilated and proliferated vessels in the deep dermis and subcutaneous tissue. These cells were positive for L-26 and kappa light chain, and negative for lambda light chain, factor VIII-related antigen, CD30, CD34, CD68 and UCHL-1. These findings confirmed the diagnosis of intravascular large B-cell lymphoma. A laboratory examination showed a high level of LDH and abnormal cells in the bone marrow. An MRI of the brain and computed tomographic (CT) scans of the chest and abdomen revealed no evidence of malignancy. Before the treatment, the size of the nodules decreased spontaneously by about 50% in one month and significantly in two months. Although combination chemotherapy, which consisted of CHOP, brought her partial remission, she experienced neurological symptoms 6 months after the initial treatment and died of brain metastasis 9 months after the treatment. CONCLUSIONS: This is a unique case for two following reasons: 1) the first biopsy revealed non-specific findings compatible with erythema nodosum; and 2) before the treatment, the nodules regressed spontaneously. Dermatologists should take multiple skin biopsies for EN lesions with the non-specific histopathological findings not to refute the existence of this disease.

Photodynamic therapy based on combined use of 5-aminolevulinic acid with a pheophorbide-a derivative for murine tumors.

BACKGROUND: 5-Aminolevulinic acid (5-ALA)-based photodynamic therapy (PDT) appears to be a promising cancer treatment modality. Here, we investigated whether enhancement of 5-ALA-PDT by combining another photosensitizer, a pheophorbide-a derivative (PH-1126), is an option. MATERIALS AND METHODS: PH-1126 (2.5, 5 or 10 mg/kg.bw) and 5-ALA (168 mg/kg.bw) were injected i.p. into C3H/HeN mice bearing squamous cell carcinoma (SCC) or BALB/c nude mice bearing L5178Y lymphoma. Afterwards, these mice received laser irradiations (630 nm for 5-ALA and 650 nm for PH-1126) with a total dose of 88 J/cm2. The results showed that PDT with 5-ALA plus PH-1126 at a low dose (2.5 mg/kg.bw) were well tolerated by both animal models, with resultant synergistically enhanced inhibition of tumor growth and/or survival advantage for the treated animals. CONCLUSION: This study demonstrated the usefulness of the combination of a low dose PH-1126 with 5-ALA for PDT of experimental tumors in vivo.

Atrophic dermatofibroma. Elastophagocytosis by the tumor cells.

A 55-year-old woman presented with an asymptomatic red plaque on the left upper back for 6 or 7 years. The lesion was depressed in response to finger pressure. The clinical diagnosis was anetoderma. Histopathologically, the characteristic cells of cellular dermatofibroma proliferated within the thinned dermis, which showed atrophy of about 60 or 70%. The proliferated cells were positive for factor XIIIa and negative for CD34. The involved dermis showed the loss of elastic fibers on elastica van Gieson stain. Electron microscopically, the proliferating cells phagocytized the elastic fibers. We report a typical case of atrophic dermatofibroma and show the possibility that the cause of this disease might be elastophagocytosis between the collagen fibers by the dermatofibroma cells.

Combination effect of photodynamic and sonodynamic therapy on experimental skin squamous cell carcinoma in C3H/HeN mice.

We studied a combination of photodynamic therapy (PDT) and sonodynamic therapy (SDT) for improving tumoricidal effects in a transplantable mouse squamous cell carcinoma (SCC) model. Two sensitizers were utilized: the pheophorbide-a derivative PH-1126, which is a newly developed photosensitizer, and the gallium porphyrin analogue ATX-70, a commonly used sonosensitizer. Mice were injected with either PH-1126 or ATX-70 i.p. at doses of 5 or 10 mg/kg.bw. At 24 (ATX-70) or 36 hr (PH-1126) (time of optimum drug concentration in the tumor) after injection, SCCs underwent laser light irradiation (88 J/cm2 of 575 nm for ATX-70; 44J/cm2 of 650 nm for PH-1126) (PDT), ultrasound irradiation (0.51 W/cm2 at 1.0 MHz for 10 minutes) (SDT), or a combination of the two treatments. The combination of PDT and SDT using either PH-1126 or ATX-70 as a sensitizer resulted in significantly improved inhibition of tumor growth (92-98%) (additive effect) as compared to either single treatment (27-77%). The combination using PH-1126 resulted in 25% of the treated mice being tumor free at 20 days after treatment. Moreover, the median survival period (from irradiation to death) of PDT + SDT-treated mice (> 120 days) was significantly greater than that in single treatment groups (77-95 days). Histological changes revealed that combination therapy could induce tumor necrosis 2-3 times as deep as in either of the single modalities. The combination of PDT and SDT could be very useful for treatment of non-superficial or nodular tumors.

A case of combined nevus: compound nevus and spindle cell Spitz nevus.

Combined nevi consisting of a Spitz nevus and an acquired nevus are unusual, and, to our knowledge, the combination of a spindle cell Spitz nevus and an overlying compound nevus has not been previously reported. We report a 17-year-old girl with a nodule on the left anterior lower extremity. The nodule was asymptomatic, firm, brown, symmetrical, dome-shaped, 8 mm in diameter, and not found with ulceration. Histological findings showed proliferation of spindle-shaped cells with an overlying compound nevus. The spindle-shaped cells were large, non-pigmented, uniform in size and shape, with rare mitoses and without nuclear atypia, and arranged in a storiform pattern in thick collagen bundles. They stained positively for S-100 and negatively for HMB-45. The lesion was considered to be a new type of combined nevus consisting of a spindle cell Spitz nevus and an overlying compound nevus.

Ichthyosis follicularis with alopecia and photophobia in a mother and daughter.

A mother and daughter having ichthyosis follicularis with alopecia and photophobia (IFAP) are reported, with histopathological and electron microscopic findings. We have followed the clinical course of the mother for 26 years since she was 5 years old, and the daughter since birth. They have had almost all the classical and some of the minor symptoms of IFAP, including severe photophobia, extensive non-inflammatory follicular hyperkeratosis, generalized non-scarring alopecia, hyperkeratosis of the extensor aspect of the four extremities, nail deformity and recurrent cheilitis. In addition, their facial appearance greatly resembles that of previously reported patients. A consistent feature in the mother was florid keratotic inflammatory eruptions on the genital region during each of her pregnancies, which rapidly improved after the delivery. Skin biopsy of the genital lesion showed marked acanthosis with dyskeratosis and spongiotic changes. The electron microscopic examination of diseased skin showed damaged desmosomes with spongiosis. No obvious changes were found in normal appearing skin.

The ultrastructural characteristics of eccrine sweat glands in a Fabry disease patient with hypohidrosis.

As an investigation of the pathogenetic mechanism of diminished sweating in Fabry disease, an electron microscopy ultrastructural study was conducted on specimens of eccrine sweat glands from a typical patient with Fabry disease who had hypohidrosis, a low skin moisture content, and diminished thermoregulation ability. Numerous characteristic cytoplasmic inclusions were observed in the eccrine sweat glands, the lamellar pattern of which was considerably variable in various types of gland cells. Large vacuolar inclusions predominated in clear cells of secretory coil; lesser vacuoles were also seen in the coiled duct, and the basal cells of the straight duct toward the coiled duct displayed mulberry-like figures. There were some clear cells showing cell damage and necrosis in the secretory coil. Lamellated inclusions were noted in the unmyelinated axons innervating the eccrine sweat glands. The small blood vessels around the eccrine glands were narrowed by swollen endothelial cells with heavy inclusions. These intracytoplasmic deposits may be responsible for the decreased sweating ability in Fabry disease. The factors related to hypohidrosis are also discussed.

The ultrastructural findings of Charcot-Leyden crystals in stroma of mastocytoma.

Charcot-Leyden crystals (CLCs) have been found in many conditions associated with eosinophilia, but their occurrence in skin diseases is very rare. We report ultrastructural observations on the presence of CLCs in the cutaneous lesions of two cases of mastocytoma. Electron microscopy documented CLCs located in phagosomes of morphologically activated macrophages as well as free CLCs in the stromal tissue, close association between CLCs formation and damaged and lysed eosinophils was present. These findings provided evidence that the formation of CLCs in mastocytoma implicated the individual and interrelated biology of mast cells, eosinophils and macrophages. Phagosomes probably acted as the site of CLCs formation. The clinic and pathologic role of CLCs in mastocytoma deserves further investigation.

Papillary eccrine adenoma with a pomegranate-like appearance.

Papillary eccrine adenoma (PEA) is a rare cutaneous tumor which histopathologically presents numerous intradermal tubular structures with inward papillary projections. Only a few cases of PEA have been reported recently. We report a case of PEA of a 58-year-old Japanese man. The marked hyperkeratosis and pits gave the tumor the clinical appearance of a burst-open pomegranate. Compact hyperkeratosis within proliferated epidermis contained spiral ducts mimicking intraepidermal eccrine sweat ducts histopathologically. These keratinous structures were thought to correspond to the pores. Several tubular structures running up to the overlying thickened epidermis were observed in the upper dermis. With these findings and with immunohistochemical studies, we proposed that this tumor originated from eccrine sweat ducts.

Dermal dendrocyte hamartoma with stubby white hair: a novel connective tissue hamartoma of infancy.

A previously undescribed hamartoma with stubby white hair was observed in a 1-week-old girl. A deep red, soft nodule with fine wrinkles was present on the back. White bizarre short thick hairs with irregular exterior cuticular squamae were noted. The main cells proliferating in the nodule were fibroblast-like spindle cells that had dendrites and showed positive staining for CD34 antigen. These cells surrounded vessels and nerves. In addition, there were immature hair follicles, relatively thick-walled small vessels, and small adipose cells with fine connective tissue. This hamartoma was considered to be a dermal dendritic cell hamartoma originating from CD34-positive cells.