Toshihiko Numahara

Spatial data analysis by epidermal Langerhans cells reveals an elegant system

Langerhans cells are dendritic cells situated in the mammalian epidermis. In human epidermis, the concentration is between 460 and 1000 mm(-2). Langerhans cells fulfill an essential role in skin immune responses. Numerous scientific reports on Langerhans cells have appeared, but with no systematic research on the pattern of the spatial distributions. On the contrary, in certain fields, a spatial distribution is an important theme, and spatial data analysis has a long history. We hypothesized that epidermal Langerhans cells were set in the best formation for their immuno-surveillance by a sophisticated mechanism. To prove this hypothesis, we have imported spatial data analysis into the study of epidermal Langerhans cells. Here, we show that the distribution is completely regular; the pattern of Voronoi divisions fits the territories; the random packing model simulates their bone marrow derivation; a repulsive interaction is demonstrated and a repulsive potential function is estimated. Spatial data analysis-based computer simulation will be a new method of Langerhans cell study. In addition, this procedure shows promise for future distribution research of certain cells.

Mathematical assessment of the spatial distribution of Langerhans cells in guinea pig epidermis

Two mathematical indexes, Hopkins-Skellam index (HSI) and Morisita index (MI), were applied to assess the distribution of ATPase-stained epidermal Langerhans cells (ELC) in the guinea pig skin. To our knowledge, this is the first report in which the degree of regularity has been expressed numerically by computation based on theoretical equations. The regularity of ELC in the normal skin was confirmed by the value of HSI (P < 0.0001). In the topical steroid applied skin, the number of ELC decreased significantly but the value of HSI was similar to that of the normal skin; while in the ultraviolet B (UVB) exposed skin, both number of ELC and regularity of ELC distribution decreased significantly. The graph of MI for the UVB exposed skin clearly showed that the distribution of ELC had local clumps. The two indexes, HSI and MI have been quite useful for determining the regularity of ELC. These indexes may have a wide application to other cells.

Eccrine gland cancer forming extensive ulcer in thigh.

A 74-year-old female presented in January 1995 with indurated plaques and ulcerson her left thigh. These lesions had first appeared as nodules at the age of about 60 years and had slowly spread and ulcerated. The patient had never received anytreatment for the skin lesions because of her antipathy to doctors.Physical examination revealed numerous indurated erythematous plaques withsuperficial ulcers and nodules on the left thigh and edematous swelling of the entireleft leg. Several indurated erythematous plaques and nodules were also seen on theleft lower leg, perineum and right inguinal resion. A chest X-ray showed pulmonarymetastatic lesions and atelectasis of the left lung field. CT scan disclosed swelling ofthe celiac lymph nodes but no tumor originated from internal organs. Serum CA-125 level was elevated in all the course of the disease. We supposed that the neoplasm onthe patients left thigh originated from the skin. She died of multiple organ failure in March 1995.Histologically, the many tumor cell nests were seen. in the dermis. Some of themshowed restiform-like pattern. Vacuoles were also seen in the tumor cell. Electronmicroscopical examination revealed tonofilaments in tumor cells, cell membraneswith complex interdigitating microvilli-like processes, desmosomes and intracellulartubules. These findings suggest that the neoplastic cells differenciated to eccrinesweat gland, and especially resemble eccrine porocarcinoma.

A case of axilla apocrine cancer.

A 52-year-old woman was admitted to our hospital in February 1991 with an intracutaneous tumor on the left axilla which was noticed as a small mass at the age of 20 and began to enlarge for the last 4 months.On admission, the tumor was firm, approximately 2.4cm in diameter, purplish red and showed radial folds on the surface.Histologically, the tumor was located in the dermis and subcutaneous tissue. The overlying epidermis was papillomatous. Numerous degenerated elastic fibers were seen in the upper and middle dermis.The tumor cells with eosinophilic cytoplasm tended to form tubular structures. Tubular luminal cells often showed decapitation secretion in the central part of the tumor.In the peripheral portion, the cells were atypical in part and showed invasive proliferation to the adjascent, along with vascular and nerve tissues. Transitional form of cells were seen between cetral and peripheral part of the tumor. A few apocrine glands were found in the stroma.Immunohistochemical studies revealed that all tumor cells were positive for EMA and keratin, negative for S-100 protein but CEA was pratially reactive in the periph-eral portion. Electron-microscopic study revealed apocrine and merocrine secretion.Widespread radical excision was performed and lymph node metastasis was found. There was no recurrence or metastasis at follow-up 16 months later.The tumor was diagnosed as apocrine carcinoma arising from axillary apocrine apparatus, however a possible diagnosis of carcinoma derived from accessory mamma remained to be ascertained.