Noriyuki Misago

Association of nevus sebaceus with an unusual type of “combined nevus”

A case of nevus sebaceus with development of a basal cell epithelioma is described. This case of nevus sebaceus was characterized by an association with extensive nevoid growths of melanocytes in the same lesion. The nevoid growths of melanocytes showed features of an unusual “combined nevus”, representing a combination of speckled lentiginous nevus with blue nevi. We discuss the relationship between nevus sebaceus and nevoid growths of melanocytes.

Spatial relationship between Merkel cells and Langerhans cells in human hair follicles

The distributions of Merkel cells and Langerhans cells within human hair follicles have been reported. However, there has been no description of the relationship between Merkel cells and Langerhans cells, which were discovered by 19th century German pathologists. Merkel cells and Langerhans cells share some similar characteristics such as the localization of human hair follicles, a close association with peripheral nerves and the expression of several neuropeptides. Merkel cells were stained with CK20 or CAM5.2, while Langerhans cells were stained with CD1a or S-100 protein. We thus immunohistochemically confirmed the preferential localization of Merkel cells and Langerhans cells in normal human hair follicles. Using a double staining technique, two- and three-dimensional observations demonstrated that a small proportion of Merkel cells were closely contacted with Langerhans cells below the sebaceous gland level, presumably indicating the bulge area. Merkel cells and Langerhans cells connected directly or approached each dendrite within the basal layer of the outer root sheath. For the first time, we demonstrated a close anatomical relationship between Merkel cells and Langerhans cells within the bulge area of human hair follicles where follicular stem cells may be present. These morphological observations suggest a functional interaction between follicular Merkel cells and Langerhans cells. We herein hypothesize that Merkel cells communicate with Langerhans cells by characteristic dendrites in which some neuropeptides or cytokines may be stored.

Basal Cell Carcinoma in Association with Multiple Trichoepitheliomas

We report the case of a basal cell carcinoma (BCC) associated with multiple trichoepitheliomas (TEs) and include the results of histopathological and immunohistochemical studies. The patient had a large, pigmented nodule associated with 4 flesh-colored papules in the central facial area. Two of the 4 flesh-colored papules and the large pigmented nodule were excised. Histopathologically, the pigmented nodule was diagnosed as BCC and 2 of the papular lesions were diagnosed as TEs. In both the BCC and TEs, almost all of the basaloid aggregations were diffusely positive for cytokeratin (CK) 19, CK8 and CK8/18. Based on these clinicopathological observations and reports in the recent literature, these two neoplasms are considered to be highly related. BCC appears to differentiate toward follicular germinative cells, and TE is its benign counterpart.

HIV‐Associated Eosinophilic Pustular Folliculitis: Successful Treatment of a Japanese Patient with UVB Phototherapy

We report the successful treatment with ultraviolet B phototherapy of a patient with HIV‐associated eosinophilic pustular folliculitis. We were able to observe the clinical and therapeutic course for about one year and three months. This 35‐year‐old homosexual Japanese man presented with disseminated, discrete, follicular, erythematous papules with intense pruritus over his face, neck, chest wall, and upper back. Initially, the eruption responded to therapy with topical or oral indomethacin and oral H1 antihistamine. However, the eruption was highly prone to recurrence, and it gradually failed to respond to these therapies. The eruption became chronic and persistent and manifested the excoriated, prurigo‐like nodules that are typical of reported pruritic papular eruption, suggesting that this skin disease and HIV‐associated eosinophilic pustular folliculitis are two forms of the same disease entity. UVB phototherapy in small doses was very effective for the persistent eruption, and no recurrence of the eruption was noted during or since the six‐month maintenance therapy (once a week at a dose equivalent to 0.75 of the minimal erythema dose) (9 months total). No unfavorable side effects have been observed during or after the UVB phototherapy (cumulative UVB doses of 2,320 mJ/cm2).

A Single Lesion Demonstrating Features of Eccrine Poroma and Poroid Hidradenoma

A case of a single poroma lesion with the features of eccrine poroma and poroid hidradenoma is reported. The patient was a 61‐year‐old woman with a soft nodule, light brown in color, located on the posterior aspect of the right knee and containing a pigmented papular lesion in its center. The histological features of the papular lesion and the nodule were consistent with those of eccrine poroma and poroid hidradenoma, respectively. The eccrine poroma portion consisted mostly of poroid cells. The number of cuticular cells was slightly greater than that of poroid cells in the poroid hidradenoma portion. The cuticular cells in this portion as well as the poroid cells in both portions were immunohistochemically positive for epithelial membrane antigen. The findings in this case suggest that there is a close relationship between eccrine poroma and poroid hidradenoma and support the view that poroid hidradenoma is a type of poroma.

Trichilemmal Carcinoma Occurring in a Lesion of Solar Keratosis

A case of trichilemmal carcinoma occurring in a lesion of solar keratosis was reported. A 92‐year‐old woman had an erythematous plaque on her face that contained a reddish nodule. Histological examination of the nodule revealed typical features of trichilemmal carcinoma accompanied by those of solar keratosis in the marginal zone. The histological features of the erythematous plaque corresponded with those of solar keratosis. However, in situ the carcinoma developed in the epithelium of a hair follicle as well as in the interfollicular epidermis in the lesion of solar keratosis. We considered it likely that bowenoid malignant transformation occurred in both interadnexal and adnexal epithelium because of actinic damage, and a trichilemmal carcinoma arose. The paper also discussed the histogenesis of trichilemmal carcinoma.

Unilateral Dysplastic Nevi Associated with Malignant Melanoma

A case of dysplastic nevi associated with malignant melanoma was reported. The case was characterized by unilateral distribution of dysplastic nevi. Multiple dysplastic nevi were observed only dorsally on the patients left upper quadrant. To the best of our knowledge, the report of this form of dysplastic nevi is the first in Japan. In addition, dysplastic nevus cell nests were present in histologic contiguity with intraepidermal proliferation of melanoma in the radial growth phase. Histological evidence suggested that the melanoma in our case had probably been derived from the context of dysplastic nevus.

Cutaneous Polyarteritis Nodosa: Therapy and Clinical Course in Four Cases

Cutaneous polyarteritis nodosa (PN) has a benign and chronic course; relapses are frequently associated with steroid dependence. We have observed four cases of cutaneous PN in the past 15 years and followed up two of the four cases long‐term for 13 and 10 years after diagnosis. There has been a marked contrast in the clinical courses of these two cases: one case has shown a complete remission for 12.5 years without treatment during the most recent 11 years; the other case had four relapses and has never experienced cessation of treatment. The only difference between the two cases was careful therapy with adequate prednisolone in the long‐term remission case. The other two cases clinically showed erythema nodosum‐like features, and they had antecedent sore throats and embedded chronic tonsillitis; one was associated with presumed streptococcal infection. These two cases may simply be an accelerated process of post‐streptococcal erythema nodosum rather than typical cutaneous PN. We performed tonsillectomies as adjuvant therapy in these two cases. No relapse of the disease has been observed in these two cases, and the tonsillectomy allowed us to taper the dose of steroids, resulting in discontinuation of the treatment in one of the two cases. The duration of the remission as well as the adjuvant therapy was variable in each of our cutaneous PN cases. Tonsillectomy can be recommended as an adjuvant to steroids for PN cases with chronic tonsillitis and/or streptococcal infection.

The importance of serum creatine phosphokinase level in the early diagnosis, and as a prognostic factor, of Vibrio vulnificus infection

Background Vibrio vulnificus infection causes rapidly progressive skin lesions and sepsis in compromised hosts with liver cirrhosis, and is often fatal. Early diagnosis and rapid treatment are important.

A Combination of Speckled Lentiginous Nevus with Patch‐type Blue Nevus

A peculiar case of “nevus on nevus” was reported. A 67‐year‐old man had had a pigmented lesion in the left hypochondrial area since birth. The clinicopathologic findings of the pigmented lesion revealed a combination of speckled lentiginous nevus and patch‐type blue nevus. This case of “nevus on nevus” is not described under the term of combined nevus as is current in the literature; it was considered to be a subtype of the type II atypical blue nevus described by Kawamura.