Intraepidermal epithelioma is a rare cutaneous neoplasm characterized histologically by intraepidermal collections of malignant appearing keratinocytes preserving the epidermal architecture. In our case, the tumour unusually showed parakeratosis and dermal invasion. There were a few reports which exhibited parakeratosis and invasion. So, we suggest there may be correlation between these factors.
Carcinoma* ; Keratinocytes ; Parakeratosis

Granular parakeratosis is a recently recognized disorder of keratinization that is usually confined to intertriginous areas. The histopathologic features are distinctive and diagnostic. Rarely, histopathologic variants such as follicular granular parakeratosis and granular parakeratosis of eccrine ostia have been described. In this report, we describe a rare case of granular parakeratosis mostly confined to eccrine ostia.
Eccrine Glands ; Keratins ; Neck ; Parakeratosis

DNA replicating cells were detected in the psoriatic epidermis by anti BrdU antibody after incubating tissue sections biopsied in acute and chronic areas with BrdU. The expression pattern of No. 1 keratin, involucrin. filaggrin, loricrin and transglutaminase E was studied in the paraffin embedded sections of psoriatic specimen which showed various histopathological findings. The results are as follows 1) The labeling index of BrdU in lesional psoriatic skin was significantly greater than that in normal skin. The labeling index was greater in the clinically active lesion of psoriasis than that of the chronic lesion, which suggest that psoriatic lesions are composed of distinct lesions differing in activity. 2) In the epidermis of the psoriatic plaques with extensive parakeratosis or microabscesses at the base of the stratum corneum and absent granular layers, the expression pattern of five epidermal proteins appeared as follows : No. 1 keratin which is found in normal epidermis immediately above the basal layer, appeared several layers higher. Involucrin was detected in most of the suprabasal layers. Fillaggrin, loricrin and transglutaminase E showed negative expression. The results obtained in the present study suggest that the increment of DNA replicating cells and aberrant, maturation pathway of epidermis appear in active psoriatic plaques.
Bromodeoxyuridine ; DNA ; Epidermis ; Paraffin ; Parakeratosis ; Psoriasis ; Skin*

Focal acantholytic dyskeratosis (FAD) was introduced by Ackerman to describe a group of clinically various dermatologic conditions having a similar histologic appearance. The characteristic histologic findings included (1) suprabasilar clefts around preserved papillae, (2) acantholytic and dyskeratotic cells at all levels of the epidermis, and (3) hyperkeratosis and parakeratosis. Almost solitary lesions of FAD are histologically incidental or clinically nodular(warty dyskeratoma). The papular form of solitary FAD is an extremely rare condition identified by the reviewing of specimens or reported as a solitary lesion developing in the mouth. We report a case of focal acantholytic dyskeratosis presenting as a solitary papule on the perianal area.
Epidermis ; Flavin-Adenine Dinucleotide ; Mouth ; Parakeratosis

We present a case of BLK developed in a 43-year-old Caucasian female. She had an asymptomatic, 4mm-sized, scaly erythematous papule on her left forearm. On histologic examination, this case showed a focal parakeratosis, hyperkeratosis, focal hypergranulosis and basal vacuolar degeneration in the epidermis, as well as band-like lymphohistiocytic infiltration with melanophages and solar elastosis in the dermis. The skin lesion was totally excised and no recurrence was noted.
Adult ; Dermis ; Epidermis ; Female ; Forearm ; Humans ; Keratosis* ; Parakeratosis ; Recurrence ; Skin

Keratosis punctata of palmar creases has been considered an uncommon variant of keratosis punctata, which itself is considered rare condition. Clinically our case, 32-year-old seaman, shows cup-shaped depression of the epidermis of varying size, from 1-3mrn in diameter, limited to the large flexor creases of the palms and digit. The histologic features are hyperkeratotic and slight acanthotic central epidermal depression without parakeratosis and loss of granular layer. A sparse mononuclear infilterate are seen arround the capillaries in the dermal papillas. No relationship to arsenical agents, syphilis, or genetic factors can be ascertained by history.
Adult ; Capillaries ; Depression ; Epidermis ; Humans ; Keratosis* ; Parakeratosis ; Syphilis

A case of benign lichenoid keratosis(BLK) developed in a 25-year-old female is presented. She had two erythematous plaques with slightly verrucous surfaces on the lips for 4 weeks. A biopsy specirnen taken from the periphery of the lesion revealed a focal parakeratosis, the absence of granular cells, and hydropic degeneration of the basal cells in the epidermis. The upper dermal infiltrate composed chiefly of lymphacytes intermingled with a few histiocytes was also seen. The direct immunofluorescent study showed depositions of a few cytoid bodies and fibrin around the areas of the dermoepidermal junction. These plaques on her lips, demonstrating lichenoid tissue changes, cleared in 8 weeks from the evalution, without any treatment.
Adult ; Biopsy ; Epidermis ; Female ; Fibrin ; Histiocytes ; Humans ; Keratosis* ; Lip ; Parakeratosis

To evaluate whether mast cells are involved in developing pathologic feature of psoriasis, 60 biopsy specimens of patients with psoriasis were analyzed. They had not been treated for at least 1 week before skin biopsy. Histological findings in early and fully developed lesions and numbers of mast cells in their dermal papillae were investigated. The results were as follows: 1. In epidermal changes of psoriatic lesions, parakeratosis and acanthosis revealed different findings between early lesions and fully developed lesions. While early lesions revealed mounds of parakeratosis and mild to moderate acanthosis, fully developed lesions revealed confluent parakeratosis and moderate to severe acanthosis. In dermal changes of psoriatic lesions, papillomatosis revealed different findings between early developed lesions and fully developed lesions. While early lesions revealed normal to moderate papillomatosis, fully developed lesions revealed moderate to severe papillomatosis. 2. Degree of acanthosis is related to the degree of papillomatosis. The more increase in the degree of acanthosis, papillomatosis, and parakeratosis, mast cell numbers in dermal papillae were more increased. 3. Mast cell numbers in dermal papillae were more increased in fully developed lesions than early lesions. 4. These findings suggest that mast cell may play an active role in developing pathologic finding of psoriasis.
Biopsy ; Humans ; Mast Cells* ; Papilloma ; Parakeratosis ; Psoriasis* ; Skin

Spiny keratoderma is a rare disorder and consists of multiple tiny keratotic plugs on the fingers and palms, which resemble the spines on a music box. Histopathologically, the lesions show compact columns of parakeratosis, with no granular layer beneath the column and no remarkable changes in the underlying epidermis and dermis. However, it is important to recognize that the disease is associated with internal malignancies. We report a case of spiny keratoderma in a 3-year-old girl, who had no associated underlying disorder.
Child, Preschool ; Dermis ; Epidermis ; Female ; Fingers ; Humans ; Music ; Parakeratosis ; Spine

Intertriginous granular parakeratosis is a condition presenting with erythematous hyperkeratotic papules and plaques localized to the intertriginous areas such as axilla, groin and perianal area. Although the etiology of granular parakeratosis remains obscure, it is probably caused by a defect in conversion of profilaggrin to filaggrin. The defect results in a failure to degrade keratohyaline granules and to aggregate keratin filaments during cornification. We report a 59-year-old man who presented with erythematous fissured patches on the perianal area for 1 year. Histopathologic examination revealed mild acanthosis and severe parakeratosis with prominent keratohyaline granules in the epidermis and vascular proliferation and RBC extravasation in the dermis.
Axilla ; Dermis ; Epidermis ; Groin ; Humans ; Middle Aged ; Parakeratosis*