摘要:

Five examples of a distinctive sebaceous malformation, designated “folliculosebaceous cystic hamartoma.” form the basis of this study. Criteria are proposed for specific diagnosis of this hamartoma and for differentiation of it from sebaceous gland hyperplasia. steatocystoma. dermoid cyst of skin, and sebaceous trichofolliculoma.

ISSN:0193-1091    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

A number of double immunocytochemical labeling techniques are available that allow simultaneous identification of two antigens in one tissue section. Those most commonly used are (a) the acid elution method, which uses acid buffer to remove one set of antibodies, thus allowing a second set to be applied; (b) the use of non-cross-reacting combinations of immunoglobulin subclass and subclass-specific antibodies; and (c) application of the diaminobenzidine (DAB) reaction product as an antibody-blocking reagent, preventing cross-reaction of one set of antibodies with those of a second labeling method. We assessed each technique, using a variety of immunoenzyme methods, for the ability to label antigens that are anatomically separate in one tissue section and those that are colocalized on the same cell surface. Acid elution methods increased antibody cross-reaction. The use of immunoglobulin subclass antibodies resulted in inferior staining. The DAB blocking method, using peroxidase antiperoxidase (DAB substrate) and alkaline phosphatase antialkaline phosphatase (APAAP) (fast red substrate) optimally labeled non colocalized antigens. The substitution of fast blue as the APAAP substrate proved optimal for colocalized antigens, producing brown and blue single-labeled and black double-labeled cells.

ISSN:0193-1091    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Currently it is well established that each of the three parts of the hair follicle (infundibulum, isthmus, and the inferior portion) originates different types of cutaneous cysts. Thus, follicular cysts include infundibular, trichilemmal. and matricial cysts. Brownstein in 1983 described a mixed type of cutaneous cyst combining epidermoid. infundibular, and trichilemmal types of keratinization. We review and illustrate the different combinations of follicular hybrid cysts reported to date: infundibular and trichilemmal cyst, infundibular and pilomatricoma cyst, trichilemmal and pilomatricoma cyst, eruptive vellus hair cyst and steatocystoma, and eruptive vellus hair cyst and trichilemmal cyst. Therefore, the concept of hybrid cyst should not be restricted to those composed of infundibular and trichilemmal cysts, because any cyst arising from the various parts of the pilosebaceous unit can combine with others to form a large series of follicular hybrid cysts.

ISSN:0193-1091    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Two cases of cutaneous herpesvirus infection are described that clinically masqueraded as pseudolymphoma. Light microscopy demonstrated typical viral changes involving pilosebaceous complexes with sparing of the surface epithelium. Dermal changes consisted of a dense perivascular and perifollicular inflammatory infiltrate. Multinucleated lymphoid cells were found in the dermis in one case and viral inclusions in fibroblasts were present in the other case. Immunoperoxidase stains with antisera to herpes simplex virus types I and II were positive in one case and negative in the other case. Ultrastructural examination demonstrated viral particles consistent with herpesvirus in both cases. Recognition of typical histologic features of herpesvirus folliculitis will lead to an accurate diagnosis in these types of clinically unsuspected cases.

ISSN:0193-1091    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The biological behavior and appropriate therapy of recurrent basal cell carcinoma (BCCA) is controversial, with some studies suggesting that this tumor becomes more aggressive with each recurrence, and other studies indicating that the majority are aggressive from the onset. The authors studied the histologic evolution of BCCA by comparing 29 original tumors with their subsequent recurrences to determine if there were any predictable histologic changes. There were borderline statistically significant changes only in degree of fibrosis, prominence of nucleoli, and mitotic frequency. There were no statistically significant changes in any of the other parameters, including those that were shown previously to be predictive of recurrence or aggressive behavior. The results of this study clearly indicate that the majority of recurrent BCCAs are aggressive from the onset, and that in many cases this can be predicted from the histomorphology of the original tumor.

ISSN:0193-1091    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The morphology and prevalence of different forms of cell degeneration in hair follicles in acute alopecia areata were investigated. In addition to apoptosis and necrosis, a third morphological pattern of cell degeneration, dark-cell transformation, was evident. Fifteen patients with untreated acute alopecia areata and three normal adults without hair loss were studied. Electron microscopy revealed that although apoptosis of outer root sheath keratinocytes produces normal hair follicle involution (catagen), increased levels of apoptosis. necrosis, and darkcell formation appear to be related to the pathology of alopecia areata. Although cell degeneration was generally restricted to keratinocytes of the lower follicle, melanocytes, Langerhans' and dermal papilla cells were also affected. Keratinocytic degeneration may affect layers of matrix cells in alopecia areata, unlike the apoptosis of scattered outer root sheath cells in normal catagen. The extent of cell death suggests a pathological rather than a physiological event in alopecia areata.

ISSN:0193-1091    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

In order to clarify the three-dimensional structure of Kaposi's sarcoma (KS) five cases of KS of the skin were observed with a scanning electron microscope (SEM). KS lesions were investigated both in vascular and spindle cell areas and were compared with similar areas observed by light microscopy. KS appears as a spongelike neoplasm consisting of irregular vascular channels lacking endothelial cells and well-developed basement membranes. Vascular spaces and vascular slits are packed with numerous red blood cells (RBCs). SEM features of KS share some similarities with those of hemangiopericytoma, a vascular tumor composed of mature endothelial cells surrounded by pericytes. These findings are consistent with the hypothesis according to which the proliferating cells of KS are viewed as immature endothelial cells with partial differentiation into pericytes.

ISSN:0193-1091    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

We studied biopsy specimens taken from the scalp of four normal volunteers by transmission electron microscopy (TEM). At the suprabulbous level of the follicle, where the cells of Henle's layer are fully keratinized but the cells of Huxley's layer are not, the cytoplasmic processes of Huxley's layer (“Flügelzellen”) reach the cells of the outer root sheath through the keratinized cylinder of Henle's layer. This junction between the outer root sheath cells and the “Flügelzellen” has not been previously characterized ultrastructurally. It is peculiar in its total lack of desmosomes, and it may have the features of a gap junction. The function of this structure and its possible role in hair growth is unknown. It may be related to nutrition, differentiation, or both.

ISSN:0193-1091    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

In some individuals habitual cheek and lip biting becomes a fixed neurosis. Pieces of oral mucosa are actually torn free from the surface, producing a distinctive clinical appearance termed morsicatio buccarum et labiorum. Sometimes it may be confused with other dermatological disorders involving the oral mucosa, and can lead to misdiagnosis. Most patients with this condition are unaware of their habit and will not aid in the diagnosis. We suggest that the histopathological features of this condition are distinctive, if not pathognomonic, and that an accurate diagnosis should be rendered if a biopsy sample is taken. Two cases are reported herein that were originally misdiagnosed as pemphigus, one of which resulted in complications of improper oral corticosteroid use.

ISSN:0193-1091    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

An unusual adnexal tumor on the scalp of a 59–year-old woman with hereditary trichoepithelioma is reported. After the initial removal, the tumor recurred twice during a 4–year period. Mohs micrographic surgery resulted in full excision of the lesion. Two years later there was no evidence of recurrence. Histologic examination of the tumor showed it to merge with adjacent areas of classic trichoepithelioma. The tumor showed cytologic atypia, mitotic figures, necrosis, deep infiltration, and features of pilar differentiation including clear cells, reminiscent of cells of the follicular outer root sheath, and focal shadow-cell formation. The differential diagnosis of this malignant follicular neoplasm included pilomatrix carcinoma and basalcell carcinoma with matrical differentiation. The unique clinicopathologic features, however, raised consideration of a “malignant trichoepithelioma.”

ISSN:0193-1091    

出版商:OVID    

年代:1991

数据来源: OVID