BACKGROUND: There is a long-standing controversy whether melanocytes in vitiligo of more than 1 year duration are actually lost or still present. Resolving this matter is essential in understanding the underlying pathology and for the development of the treatment. On previous immunohistochemical and ultrastructural studies of vitiligo lesions, damage of melanocyte and keratinocyte in early lesions were reported and complete absence of melanocyte in long standing lesions were known. OBJECTIVE: This study aimed to determine the existence of the differences in pathologic changes in melanocytes according to the duration of the lesion. METHODS: We investigated the vitiliginous skin samples from 31 patients with early(less than 1 year duration) vitiligo and 30 patients with long standing(l to 5 years duration) vitiligo under the electron microscopy. RESULTS: Multiple degenerative changes in melanocytes were observed in the early and long standing lesions. In long standing lesions, degeneration of melanocytes including pyknotic, in-dented nuclei, vacuolated cytoplasms and blunted dendrites were more pronounced than early lesions. Even in long standing lesions, definite or presumptive melanocytes were observed in 16(53.3%) of 30 cases. CONCLUSION: Our results suggest that the melanocytes of vitiligo lesions were damaged and that the percentage of degenerative changes increase in accordance with the duration of the lesion. However, in long standing lesions as well as in early lesions, some residual melanocytes can be observed ultrastructurally.
Cytoplasm ; Dendrites ; Humans ; Keratinocytes ; Melanocytes ; Microscopy, Electron ; Pathology ; Skin ; Vitiligo*

We reported two cases of clinically typical melasma presenting with unusual histopathologic findings. In one case, the epidermal melanocytes were markedly increased in number and protruded into the dermis, and in the other case, increased epidermal pigmentation as well as dermal melanocytosis were found. We suggested that the various treatment modalities of melasma should be applied depend on its histopathologic finding.
Melanosis/*pathology ; Melanocytes/pathology ; Humans ; Female ; Epidermis/pathology ; Dermis/pathology ; Adult

Ota's nevus is mongolian spot-like macular blue-black or gray-brown patchy pigmentation that most commonly ocurrs in areas innervated by the first and second division of the trigeminal nerve. Acquired, bilateral nevus of Ota-like macules (ABNOM) is located bilaterally on the face, appears later in life, is blue-brown or slate-gray in color. It is not accompanied by macules on the ocular and mucosal membranes. There is also debate as to whether ABNOM is part of the Ota's nevus spectrum. We report an interesting case of ABNOM associated with Ota's nevus. A 36-yr-old Korean women visited our clinic with dark bluish patch on the right cheek and right conjunctiva since birth. She also had mottled brownish macules on both forehead and both lower eyelids that have developed 3 yr ago. Skin biopsy specimens taken from the right cheek and left forehead all showed scattered, bipolar or irregular melanocytes in the dermis. We diagnosed lesion on the right cheek area as Ota's nevus and those on both forehead and both lower eyelids as ABNOM by clinical and histologic findings. This case may support the view that ABNOM is a separate entity from bilateral Ota's nevus.
Adult ; Biopsy ; Face/pathology ; Female ; Humans ; Melanocytes/cytology ; Nevus of Ota/diagnosis/*pathology ; Nevus, Pigmented/diagnosis/*pathology

The pattern and morphology of cellular infiltration of iris melanocytes implanted into the corneal stroma were studied with a rabbit corneal model. Iris melanocytes are transformed into fibroblast-like cells with a loss of pigment granules, which may reflect the in vivo characteristics of iris melanocytes under pathologic conditions. The metaplastic chararter of iris melanocytes appears to be related to the formation of retrocorneal pigmentation and fibrous membrane.
Animals ; Cell Division ; Cornea/*cytology/pathology/surgery ; Iris/*cytology ; Melanocytes/*cytology/physiology/transplantation ; Metaplasia/pathology ; Rabbits

The development of human melanocyte culture in vitro from normal adult skin and uninvolved skin of vitiligo patients is essential to investigate the mechanism of depigmentation in vitiligo and other pigmentary dermatoses. By using selective growth and long-term maintenance conditions, we selectively cultured melanocytes derived from normal foreskins and arm skins, and uninvolved foreskins and arm skins of vitiligo patients. The melanocytes of the arm skins were successfully cultured from the roofs of suction blisters. Melanocyte Growth Media (MGM) consisting of MCDB-153 formulation with basic fibroblast growth factor (bFGF), bovine pituitary extract (BPE), insulin, hydrocortisone, phorbol 12-myristate 13-acetate (PMA) and 10% human AB serum was sufficient to grow the melanocytes from normal and vitiligo donors. Melanocytes from uninvolved skin of vitiligo donors showed no different morphologic features, initial seeding capacity and population doubling time compared with those from normal skin. Melanocytes from both cell types grew without any lag period for more than 6 months (6-11 passages). Melanocytes obtained from foreskins had higher initial seeding capacity and shorter population doubling time than those obtained from arm skins using suction-blistered roofs. Our results suggest that the culture method using suction blisters may be a simple and easy way to obtain melanocytes. In addition, vitiligo melanocytes can be successfully cultured with appropriate growth conditions and may show no defective growth patterns. This culture system will be applied to investigate the basic pathophysiology of vitiligo and other various pigmentary dermatoses.
Cells, Cultured ; *Cytological Techniques ; Human ; Melanocytes/*cytology/*pathology ; Reference Values ; Support, Non-U.S. Gov't ; Vitiligo/*pathology

Adolescent ; Adult ; Aged ; Cholesteatoma, Middle Ear ; congenital ; pathology ; Female ; Humans ; Male ; Melanocytes ; Middle Aged ; Young Adult

Foramen Magnum ; pathology ; Humans ; Male ; Melanocytes ; pathology ; Melanoma ; diagnostic imaging ; pathology ; Meningeal Neoplasms ; diagnostic imaging ; pathology ; Middle Aged ; Radiography ; Skull Neoplasms ; diagnostic imaging ; pathology

OBJECTIVETo study the clinicopathologic features, differential diagnosis and prognosis of proliferative nodules(PNs) in congenital melanocytic nevi(CMN).

METHODSHistopathologic evaluation and immunohistochemical study by EnVision method were carried out in 8 cases of PNs in CMN. The clinical information and follow-up data were analyzed.

RESULTSThe age of patients ranged from 1 to 54 years (mean 27.6 years). Tumors were located on face (3 cases), on back (2 cases), upper extremities (2 cases) and lower extremities(1 case). Microscopically, PNs with expansile growth were observed in 8 cases of CMN. Melanocytes in PNs show variable pleomorphism with a mitotic activity of 0 to 4 per 10 high power fields. Blending of cells with adjacent CMN was noted in 6 cases. According to the morphology of melanocytes in PNs, it was classified into different types including large oval melanocytes (4 cases), small melanocytes (2 cases) and Spitz-nevus-like forms (2 cases). Immunohistochemically, melanocytes in PNs were consistent with those in adjacent CMN. They were diffusely positive for S-100 protein, but were either negative or focally positive for HMB45. Less than 5% of melanocytes were positive for Ki-67 in 8 cases of PN. Follow-up was available in all cases, ranging from 9 to 82 months. Seven patients with excision of single PN in CMN were alive with no evidence of disease, while 1 patient with multiple PNs in CMN was stable with disease after 62 months follow-up.

CONCLUSIONSPN is a rare melanocytic lesion arising in CMN. Recognition of its specific histologic features can help to avoid being misdiagnosed as melanoma. Long term follow-up should be recommended in patients with PNs, especially in those with atypical histologic features. Further investigation is needed to elucidate its clinical behavior.

Adolescent ; Adult ; Back ; Child ; Child, Preschool ; Diagnosis, Differential ; Extremities ; Facial Neoplasms ; pathology ; Female ; Humans ; Infant ; Male ; Melanocytes ; pathology ; Middle Aged ; Nevus, Pigmented ; pathology ; Prognosis ; Skin Neoplasms ; pathology

To more fully define the nature of the antibody response to melanocytes which is associated with vitiligo, a Western immunoblot assay was used to test the sera of 28 patients with vitiligo (21 with active non-segmental, and 7 with stable segmental diseases) and 26 normal individuals for antibodies to antigens in detergent extracts of melanocyte membrane fractions. Antibodies to melanocytes were found in 26 (93%) of the patients with vitiligo, and in 16 (62%) of the control individuals. Patients with vitiligo and control individuals both had antibodies to an 80 approximately 83 kD antigen. The patient with vitiligo, in addition, had antibody responses to antigens with MWs of 45, 65, and 110 kD. Antibodies to these antigens were present in 46, 25, and 31% of vitiligo patients, but in only 19%. 0%, amd 0%, respectively, of the normal individuals. The heterogeneity of the antibody responses to melanocytes in vitiligo was further confirmed by the presence of antibodies to at least 3 distinct antigens in one-third of vitiligo patients but in none of the normal individuals. There was no difference in antibody response between patients with generalized and segmental vitiligo, suggesting that the pathogenesis of diseases was similar in both cases.
Antibodies/*analysis ; Antigens/immunology ; Blotting, Western ; Human ; Melanocytes/*immunology ; Reference Values ; Support, Non-U.S. Gov't ; Vitiligo/*immunology/*pathology

Patients with vitiligo seem be less prone to the development of lentigines as a side effect of long-term photochemotherapy than do psoriatics. An 8-year-old boy who had a vitiliginous patch on his left thigh, had been receiving photochemotherapy since he was 2 years old. At the age of 3, multiple star-shaped brownish macules developed at the site of treatment. Photochemotherapy was continued until the patient was 6 year old, at which time no improvement in the vitiligo was seen, so photochemotherapy was discontinued. Now 2 years after treatment the lentigines still persist. On electron microscopic examination, the melanocytes showed two patterns of cell death: coagulative necrosis and apotosis together with atypical cytoplasmic and melanosomal alterations.
Case Report ; Child ; Human ; Lentigo/*etiology/pathology ; Male ; Melanocytes/ultrastructure ; Microscopy, Electron ; PUVA Therapy/*adverse effects ; Vitiligo/drug therapy