Shu Sasai

Characterization of the physical properties of the stratum corneum by a new tactile sensor.

Background/aims: The physical properties of the stratum corneum (SC) change with its water content, which is regulated by the presence of water solutes (natural moisturizing factors) and lipids in the SC, and are considered to be responsible for the induction of desquamation, skin surface roughness, and fine wrinkles. Recently a new type of tactile sensor developed for evaluating the physical properties of objects has been introduced as a simple, non‐invasive method to evaluate them; because the data obtained with this sensor have not yet been characterized in detail, we compared them with other physical parameters of the skin.

Palpation of the skin with a robot finger: an attempt to measure skin stiffness with a probe loaded with a newly developed tactile vibration sensor and displacement sensor

Background/aims: Various attempts have been made to measure mechanical properties of the skin quantitatively and noninvasively. However, no attempt has been made to measure a tactile sense of our finger that palpates the skin; when we palpate the skin to search for any change, we at first rub the skin surface softly with a finger tip to detect a surface change and then press the finger against the skin to perceive any alteration in consistency. The problem here is how to record such tactile sense quantitatively, because the palpating examination for smoothness or softness of the skin totally depends on a subjective perception. A new tactile sensor from robot technology is equipped with a fingertip‐like sensing probe oscillating at a resonant frequency of 60 kHz; it is capable of clearly sensing small differences in hardness of solid substances from a change in the oscillating frequency and from a displacement sensor that detects depressability of the skin. We have used this new measuring system to evaluate the hardness and elasticity of skin.

Basal cell carcinoma showing connections with epidermal cysts.

Basal cell carcinomas arising from epidermal cysts are rare. A 76‐year‐old Japanese man had had a blackish nodule on his right knee for 15 years, under which he later noticed the development of a subcutaneous nodule. On histological examination masses of tumour cells showed the feature of adenoid and solid patterns of basal cell carcinoma that were connected to the wall of epidermal cysts in many places as well as with the overlying epidermis.

Occurrence of neutrophils and activated Th1 cells in UVB-induced erythema

We investigated the sequential changes in infiltrating inflammatory cells and several cytokine levels over a period of 48 h in human back skin exposed to 3 minimal erythematous doses of UVB. The measurement of blood flow, using a laser Doppler method, indicated that UVB-induced erythema reached a peak 12-24 h after irradiation. Immunohistochemically, an increase in the number of CD4+ T cells was observed in perivascular areas 6 h after the UVB treatment and continued for up to 48 h. CD8+ T cells were scarce until 24 h, but their numbers gradually increased thereafter. HLA-DR+ cells were detected perivascularly and interstitially in parallel with the pattern of CD4+ T-cell infiltration. In contrast, neutrophils were found 3 h after UVB exposure and reached a peak at 24 h. Using a RT-PCR method, we demonstrated that mRNAs for the Th1 cytokines (interferon-gamma and interleukin-2), together with a proinflammatory cytokine (interleukin-8), became detectable at 6 h, whereas mRNA for the Th2 cytokine (interleukin-4) was not found at all during the first 48 h. In contrast, we found an increase in mRNA levels for C3 and tumor necrosis factor-alpha even at 3 h, suggesting a relationship between complement activation and accumulating neutrophils. Our results suggest that neutrophils and CD4+ T cells in UVB-induced inflammation play different roles: neutrophils are more closely related to UVB-induced erythema, while T cells appear to be involved in subsequent dermal and epidermal inflammation accompanied by epidermal hyperproliferation.

High-frequency conductance measurement of the skin surface hydration state of dry skin using a new probe studded with needle-form electrodes (MT-8C).

Background/aims: When high‐frequency conductance measurements are performed on dry scaly skin such as atopic xerosis, senile xerosis or psoriasis, the values recorded with a flat surfaced ordinary probe tend to be lower, indicating a reduced hydration state, than the actual one, because the rough and firm skin surface prevents close contact with the hard and flat surface of the applied probe.

Coexistence of Multiple Perifollicular Fibromas and Colonic Polyp and Cancer

Perifollicular fibroma (PFF) is a rare cutaneous hamartoma that shows differentiation to the connective tissue sheath of the hair follicle. It may be solitary or multiple; the latter has been suggested to exhibit autosomal dominant inheritance and association with colonic polyposis. We report a 72-year-old Japanese female with multiple PFF on the face, possibly familial, who developed colon cancer in addition to colonic polyps.

Phaeohyphomycosis Caused by Phaeoacremonium rubrigenum in an Immunosuppressive Patient: A Case Report and Review of the Literature

Phaeohyphomycosis (PHM) is a rare, deep fungal infection of the skin and subcutaneous tissues caused by dematiaceous fungi. In this report, we describe a case of PHM caused by Phaeoacremoniumrubrigenum, which is generally known to infect woody plants. We detected the gray-blackish villi by biopsy culture material, and slide culture revealed the conidia arising from slightly tapering phialides. Furthermore, we differentiated these fungi as P.rubrigenum by Basic Local Alignment Search Tool (BLAST) algorithm. We performed surgical debridement of disseminated nodules and administered oral itraconazole for a duration of 4 weeks. One year after stopping itraconazole, there was no sign of relapsing subcutaneous nodules. To our knowledge, this is the third case report of PHM developing from skin infection by P. rubrigenum in human.

Apocrine Nevus in Abdominal Skin

Apocrine nevus, a rare tumor occurring in the axilla and upper chest, is composed of a large number of mature apocrine glands extending from the reticular dermis into the subcutis [1–8] . We describe a 47-year-old Japanese woman who presented with aggregated papules in the abdominal wall just to the left of the umbilicus. Our case is unique in that the apocrine nevus occurred outside of the regions in which apocrine glands are distributed. She had already noticed the presence of the small eruption during early childhood. It gradually increased in size with the appearance of a few erosive papules several years previously. She had been suffering from hypothyroidism for 20 years and had been taking thyroxine. The lesion consisted of aggregated brownish papules in an area of 8.5 ! 4.5 cm on her left umbilical region ( fi g. 1 a). Slightly wrinkled, linear, fi ne atrophy overlapped the lesion. A few papules were accompanied by small pits with erosive surfaces. We removed the lesion to make a diagnosis. Histologically there were numerous cysts surrounded by a small fi brous sheath ( fi g. 1 b). The luminal layers of the cysts were composed of cuboidal cells with basophilically stained cytoplasm showing decapitation activities into the luminal spaces ( fi g. 1 c). These features were consistent with those of apocrine nevus. There was no hallmark of organoid nevus, such as papillomatous epidermal hyperplasia, immature hair follicles, and sebaceous glands. On the other hand, the erosive papules, which appeared later, demonstrated the histologic characteristics of syringocystadenoma papilliferum, namely, irregularly tubular invaginations with villous or papillomatous projections into the luminal spaces ( fi g. 1 d). Gross cystic disease fl uid protein-15, a specifi c marker for apocrine epithelium, was expressed in the upper portion of the cyst walls [8] . Moreover, cytokeratin 19 was positive only in the luminal cells but not in the basal cells, which is compatible with maturated apocrine glands, because in the case of immature glands, cytokeratin 19 is expressed not only in luminal cells

Apocrine hidrocystoma on the finger.

Sir, Apocrine hidrocystomas usually present as superficial, solitary, cutaneous nodules on the face. However, it is extremely rare for apocrine hidrocystomas to develop on a finger (1, 2). According to their histological characteristics and presumed histogenetic derivation, two types of hidrocystoma have been distinguished, but the precise classification of this tumour have not been clarified. We describe here a patient with an apocrine hidrocystoma on a finger, and discuss the histopathological, histochemical and immunohistochemical features.

Congenital plantar melanocytic nevus with satellite lesions

We report a case of a congenital melanocytic nevus accompanied by a mucous cyst and satellite pigmented macules on the undersurface of the left great toe in a 17-year-old Japanese man. Myxoid change was confirmed by the discharge of viscous liquid when conducting biopsy of the tumor. Besides such an unusual clinical feature of the tumor, accompanying satellite lesions led us initially to consider the possibility of malignant melanoma. However, a biopsy specimen obtained from the tumor revealed the typical features of intradermal type melanocytic nevus. In a specimen obtained from the satellite pigmented lesion, there was a small mass of nevus cells underneath the basement membrane zone, suggestive of having originated from the spread of nevus cells through lymphatic vessels.