Recent topics of biochemical and biological progress in keratinization and dyskeratosis were reviewed and discussed. The main topics were as follows: (1) what is keratin (2) Differentiation of keratinocytes (keratinization), (3) Components of horny substances and their derivation, (4) Keratin filament and keratohyaline granule, (5) Synthesis of horny cell membrane (disulfide bonds, e- (T-glutamyl) lysine bonds), (6) Biochernical analysis of dyskeratosis (harlequin fetus, ichthyosis vulgaris, X-linked ichthyosis, lamellar ichthyosis, bullous congenital ichthyosiform erythroderma, psoriasis vulgaris, Dariers disease, M:enke's syndrome, Netherton's disease, Richner-Hanhart syndrome). These findings should lead to a more cornplete understanding of the pathologic events that occur in the process of keratinization and more rational therapy for many disorders in keratinization.
Cell Membrane ; Darier Disease ; Fetus ; Hyperkeratosis, Epidermolytic ; Ichthyosis ; Ichthyosis Vulgaris ; Ichthyosis, Lamellar ; Keratinocytes ; Lysine ; Psoriasis

Epidermolytic acanthoma is an uncommon benign tumor characterized histologically by epidermolytic hyperkeratosis. Clinically, the tumor resembles a verruca or seborrheic keratosis and may occur in either isolated or disseminated forms. Herein, we present a case of a 46-year-old male who developed multiple seborrheic keratosis or verruca like papules on his trunk which showed epidermolytic hyperkeratosis upon microscopic examination. Following clinical and histological findings, the patient was diagnosed as having disseminated epidermolytic acanthoma.
Acanthoma* ; Humans ; Hyperkeratosis, Epidermolytic ; Keratosis, Seborrheic ; Male ; Middle Aged ; Warts

We report a case of disseminated epidermolytic acanthoma in a 69-year-old male who presented numerous, small dark brown verrucous papules on both popliteal fossae, inguinal areas, and abdomen. Although each lesion clinically resembled seborrheic keratosis, light microscopic examination revealed features of epidermolytic hyperkeratosis.
Abdomen ; Acanthoma* ; Aged ; Humans ; Hyperkeratosis, Epidermolytic ; Keratosis, Seborrheic ; Male

Epidermolytic keratosis palmaris is a rare disease which shows clinical findings of Unna Thost keratoderma and histopathologic of epidermolytic hyperkeratosis. We report herein a case of epidermolytic keratosis palmaris et plantaris in a 16-month-old female baby. Light microscopy shows marked hyperkeratosis, large irregular keratohyalin granules, and large clear spaces in the granular and upper spinous layers. Eletron microscopic findings shows that the clear spaces are areas of cytoplasm filled with a fibrillar material and cellular organelles. Abnormal clumping of tonofilament and keratohyalin is also present.
Cytoplasm ; Female ; Humans ; Hyperkeratosis, Epidermolytic ; Infant ; Intermediate Filaments ; Keratoderma, Palmoplantar* ; Keratosis* ; Microscopy ; Organelles ; Rare Diseases

Benign lichenoid keratosis is an asyrnptomatic, isolated, plaque-like lesion frequently mistaken for basal cell carcinoma, Bowens disease, and actinic or seborrheic keratosis because of its variable clinical appearance. We present two cases of benign lichenoid keratosis. The first case was a 44-year-old female who had mild pruritic, ll x15rnrn sized, single, slightly elevated brownish plaque with fine scaling on the right zygornatic area of 5 years' duration. The second case was a 35-year-old female who had mild prutitic, single, pea- sized erythernatous patch on the left ala nasi of one month's duration. On histologic examination, these two cases showed same histologic findings, such as focal parakeratosis, moderate hyperkeratosis, irregular acanthosis and liquefaction degeneration of basal cells in the epidermis and band-like mononuclear infiltration and colloid bodies in the dermis.
Actins ; Adult ; Bowen's Disease ; Carcinoma, Basal Cell ; Colloids ; Dermis ; Epidermis ; Female ; Humans ; Keratosis* ; Keratosis, Seborrheic ; Parakeratosis

No Abstract Available.
Keratosis*

No abstract available.
Keratosis*

No abstract available.
Keratosis, Seborrheic*

No abstract available.
Keratosis, Seborrheic*

No abstract available.
Keratosis, Seborrheic*