Cutaneous mixed tumor containing ossification, hair matrix, and sebaceous ductal differentiation

A 58-year-old Japanese male presented with a cutaneous mixed tumor containing ossification and hair matrix differentiation on the left side of the chin. Histologically, the tumor consisted almost exclusively of apocrine-type epithelial ductal structures and chondroid stroma. Strands and aggregation of basaloid cells which contained keratinous cystic structures with a column of shadow cells arising from basophilic basaloid cells, sebaceous duct-like structures, and ossification in the stroma were also evident. These findings suggest that cutaneous mixed tumors with ossification and hair matrix differentiation are related to both the whole hair follicle and the sweat apparatus.

Postmenopausal frontal fibrosing alopecia: a frontal variant of lichen planopilaris

BACKGROUND

Lichen planopilaris usually produces multifocal areas of scarring alopecia. Recently, a condition in postmenopausal women characterized by progressive frontal hairline recession associated with scarring has been described.

OBJECTIVE

Our purpose was to study the clinical and histopathologic features and results of treatment in a group of women with the frontal variant of lichen planopilaris and to compare the immunohistochemical profile of scalp biopsy specimens from this subset with that found in the multifocal variant of lichen planopilaris.

METHOD

The clinical data as well as the histopathologic findings in 16 women with frontal fibrosing alopecia were collated. The immunohistochemical profile of six scalp biopsy specimens from the frontal hairline were compared with six specimens from women with multifocal lichen planopilaris.

RESULTS

In addition to the progressive frontal fibrosing alopecia in all 16 women, total loss or a marked decrease of the eyebrows was observed in 13. No evidence of lichen planus was observed at other sites. In one patient multifocal areas of lichen planopilaris developed in the scalp. The frontal fibrosing alopecia was slowly progressive but has stabilized in five patients. Biopsy specimens from the frontal hairline showed histologic changes identical to lichen planopilaris. Immunophenotyping failed to reveal any significant differences between the frontal and multifocal variants. No effective treatments emerged although oral steroids and antimalarials may temporarily slow the course. Hormone replacement therapy did not appear to influence the course of the alopecia.

CONCLUSION

Progressive frontal fibrosing alopecia is a clinically distinct variant of lichen planopilaris that affects in particular elderly women and frequently involves the eyebrows. The basis for this lichenoid tissue reaction targeting frontal scalp follicles and eyebrows is unknown.

Congenital alopecia areata

Alopecia areata has never been documented in a newborn. Thus, it is generally assumed that alopecia areata is acquired only postnatally, and it is believed that the presence of an alopecia at birth virtually excludes its diagnosis. In this report we document a case of alopecia areata in a premature newborn.

Congenital midline sinus of the upper lip: case report and review of literature

A case report of a congenital midline sinus of the upper lip in a 5-year-old girl is presented. The patient complained of intermittent swelling around the frenulum of the upper lip. The sinus was located on the midline of the philtrum just below the base of the columella. Excision of the sinus tract via an intraoral approach gave a satisfactory result. Microscopic examination of the resected sinus revealed it to be lined by stratified squamous epithelium with sebaceous glands and hair follicles. Fifteen other cases have been reported in the English literature and are reviewed. There are two postulates that can account for the formation of the upper lip sinus based on two major theories of the development of the face: the fusion theory and the merging theory. However, the etiology of this rare congenital sinus remains obscure.

Leukaemia inhibitory factor: induction in the early phase of allergic contact dermatitis

It has been suggested that leukaemia inhibitory factor (LIF), may be involved in the pathogenesis of cutaneous inflammation. In 5 patients with previously proven contact allergy to nickel, LIF mRNA and protein expression were assessed by reverse transcription-polymerase chain reaction and immunohistochemistry in 5% nickel sulfate patch test biopsies 24 h after application of the patch. Control specimens were obtained from non-tested and vehicle-tested skin from the same individuals. LIF mRNA expression was significantly increased in nickel-tested skin compared with both vehicle-tested (p = 0.045) and non-tested skin (p = 0.041). All biopsies showed similar patterns of LIF immunoreactivity, with no significant differences between nickel-tested, vehicle-tested and non-tested skin. Immunostaining was cytoplasmic and was present in the epidermis and hair follicles. No dermal staining was observed. This study suggests that LIF may play a role in the early phase of allergic contact dermatitis.

Chronic telogen effluvium: increased scalp hair shedding in middle-aged women

BACKGROUND

Diffuse loss of scalp hair is a common problem in middle-aged women. A segment of these cases represents idiopathic chronic telogen effluvium (CTE).

OBJECTIVE

The purpose was to establish distinctive clinical and pathologic criteria for the diagnosis of CTE to facilitate its differentiation from androgenetic alopecia (AGA) and systemic causes of chronic diffuse hair loss.

METHODS

A group of 355 patients (346 females, 9 males) with diffuse generalized thinning of scalp hair of unknown origin were classified as having CTE and were included in the study. Characteristically they presented with a history of hair loss with both increased shedding and thinning of abrupt onset and fluctuating course and showed diffuse thinning of hair all over the scalp, frequently accompanied by bitemporal recession. Two 4 mm punch biopsy specimens were taken mostly from the mid or posterior parietal scalp of these patients. The biopsies were performed at these same areas in 412 patients with AGA (193 male, 219 female). Similar paired biopsy specimens were also taken from 22 normal control subjects (13 males, nine females). Specimens were sectioned horizontally and vertically and were examined for terminal and velluslike (miniaturized) hairs, follicular stelae, follicular units, and perifollicular inflammation and fibrosis.

RESULTS

In horizontal sections of 4 mm punch biopsy specimens from patients with CTE the average number of hairs was 39, the terminal/velluslike hair ratio was 9:1, 89% of the terminal hairs were in anagen, and 11% were in telogen. In AGA these values were 35, 1.9:1, 83.2%, and 16.8%, respectively, and in normal control subjects 40, 7:1, 93.5%, and 6.5%, respectively. Significant degrees of inflammation and fibrosis were present in only 10% to 12% of cases of CTE and normal controls, but occurred in 37% of cases of AGA. CTE ran a prolonged and fluctuating course in many patients.

CONCLUSION

CTE, which usually affects 30- to 60-year-old women, starts abruptly with or without a recognizable initiating factor. It may be distinguished from classic acute telogen effluvium by its long fluctuating course and from AGA by its clinical and histologic findings.

Damage to hair follicles by normal-mode ruby laser pulses

BACKGROUND

Although many temporary treatments exist for hirsutism and hypertrichosis, a practical and permanent hair removal treatment is needed.

OBJECTIVE

Our purpose was to study the use of normal-mode ruby laser pulses (694 nm, 270 microseconds, 6 mm beam diameter) for hair follicle destruction by selective photothermolysis.

METHODS

Histologically assessed damage in ex vivo black-haired dog skin after the use of different laser fluences was used to design a human study; 13 volunteers with brown or black hair were exposed to normal-mode ruby laser pulses at fluences of 30 to 60 J/cm2, delivered to both shaved and wax-epilated skin sites. An optical delivery device designed to maximize light delivery to the reticular dermis was used. Hair regrowth was assessed at 1, 3, and 6 months after exposure by counting terminal hairs.

RESULTS

Fluence-dependent selective thermal injury to follicles was observed histologically. There was a significant delay in hair growth in all subjects at all laser-treated sites compared with the unexposed shaven and epilated control sites. At 6 months, there was significant hair loss only in the areas shaved before treatment at the highest fluence. At 6 months, four subjects had less than 50% regrowth, two of whom showed no change between 3 and 6 months. Transient pigmentary changes were observed; there was no scarring.

CONCLUSION

Selective photothermolysis of hair follicles with the normal-mode ruby laser produces a growth delay consistent with induction of prolonged telogen with apparently permanent hair removal in some cases.

Demodex-associated folliculitis

Examination of 388 follicles in 24 large resections of skin for the presence of histologic folliculitis and Demodex mites uncovered a nonrandom association between these two phenomena. Demodex mites were found in 42% of follicles with inflammation, but in just 10% of the follicles without inflammation. Eighty-three percent of follicles with Demodex showed inflammation. The probability that this result could occur by random chance alone was < 0.001, thus suggesting that Demodex is associated with histologic folliculitis, even minor folliculitis. The results do not, however, decide whether Demodex is causative, whether it preferentially selects follicles with histologic inflammation, or whether some of both processes operate.

[Tumor of the follicular infundibulum. Study of determining follicular differentiation]

Tumor of the follicular infundibulum is a rare proliferation of cells and its histogenesis or differentiation at the morphological level has been the subject of some controversy. In recent years cytokeratins have been recognized as important markers of epithelial differentiation, and of late new retrieval methods have meant it is possible to detect them in formalin-fixed and paraffin-embedded tissue. Four patients were studied, the ages ranging between the 2nd and 7th decade. The tumors were all located in the head and neck and in one case the lesion developed in a pre-existing sebaceous nevus. The morphological investigation revealed a flat, proliferation of polygonal, pale eosinophilic cells connected to epidermis or follicular infundibulum and with a centrally located nucleus. In addition, a few ductal structures resembling sebaceous ducts were seen and in one case a hair germ papilla and a follicular papilla was noted. Immunohistochemical investigations with antibodies against cytokeratins revealed differentiation comparable to that in the fetal follicular isthmus and, in one case, also differentiation in keeping with the fetal follicular infundibulum.

The pathogenesis of alopecia areata

Knowledge of the disease mechanisms in alopecia areata is discussed in the light of progress in hair biology, immunology, and genetics. A disease model is presented incorporating polygenic determination of disease severity and susceptibility with largely unknown trigger factors responsible for initiating clinical disease expression. Experimental systems including animal models for alopecia areata offer new opportunities for investigation of alopecia areata and developing novel therapies.

Cicatricial alopecia

Scarring alopecias are of diverse etiology and pathogenesis. They may be histologically classified as primary or secondary, depending on involvement of reticular dermis. The most important primary scarring alopecias include pseudopelade, lichen planopilaris, and diffuse scarring of the vertex in African-Americans. The most important secondary scarring alopecias include folliculitis decalvans and late-stage lupus erythematosus.

Transverse scalp sections: a proposed method for laboratory processing

BACKGROUND

Transverse sections of human scalp biopsy specimens can provide both qualitative and quantitative information about follicular histopathology not readily available in vertically sectioned specimens.

OBJECTIVE

We propose a method for making the processing and interpretation of such specimens easier.

METHODS

All scalp biopsy specimens obtained during the past 18 months in our institution for the evaluation of alopecia were processed for transverse sections by means of a technique employing trisection or quadrisection (rather than the standard bisection), and maintaining all sections in the same anatomic orientation (deep to superficial) in all tissue pieces on microscopic slides.

RESULTS

More than 120 transversely sectioned specimens from more than 75 patients have been processed with this technique. The typical number of slides cut per specimen decreased from between 12 and 20 to between 1 and 4, with no loss of clinical information.

CONCLUSION

This technique allows transverse sections for evaluation of alopecia to be processed in a more cost-effective manner and compares favorably with previously published techniques in providing diagnostic information.

Histopathology of cutaneous changes in non-drug-induced coma

To compare the histological features of non-drug-induced and drug-induced coma blister, we performed histopathological and immunopathological studies of four biopsy specimens from three patients with non-drug-induced coma. These results were compared with the previously well-documented histology of drug-induced coma. The findings of the present study of non-drug-induced coma included (a) a variable degree of epidermal cell degeneration, including vacuolation of basal cells, intraepidermal blister formation with pale cytoplasm, and extensive coagulation necrosis with pale nuclei; (b) alteration of the outer root sheath of telogen follicles, ranging from focal necrosis to total coagulation necrosis, and degeneration of sebaceous gland with disappearance of the germinative cell layer; (c) secretory eccrine cells with pyknotic nuclei, vacuolation of the cytoplasm, and intercellular edema, resulting in poorly defined cytoplasm, although the nuclei of the outer basal layer were partially preserved; (d) from slight edema of the vessel wall of the venules to fibrinoid, thrombosis and/or fibrinoid necrotic degeneration of arterioles and venules; and (e) deposits of immunoglobulins or complement as detected by direct immunofluorescent technique in all the three cases. One significant difference between non-drug-induced and drug-induced coma blister was the presence of fibrinoid thrombi in the lumina of non-drug-induced coma blisters. Since one of the three cases of non-drug-induced coma studied in the present report did not show thrombi in the lumina, this feature may not always be available for the differential diagnosis of these two conditions. However, fibrinoid thrombi may be a good marker for the differentiation of these two conditions, when the depth and duration of non-drug-induced coma are severe enough to induce these lesions.

Proliferating tricholemmal cyst: a possible pitfall in cytological diagnosis

We report a case of proliferating tricholemmal cyst, which made difficulties in the cytological analysis of the fine-needle biopsy aspirates. This rare dermatopathologic entity is a possible diagnostic pitfall due to its close cytological resemblance to squamous cell carcinoma-the abundance of material, with predominance of squamoid cells, which form concentric structures (so-called squamous eddies), that simulate keratin pearls of well-differentiated squamous cell carcinoma. However, careful and strict application of the cytological criteria prevents overdiagnosis; the small squamoid cells that predominate in the smears occur mainly in clusters and sheets, they do not show prominent atypia, and the squamous eddies may not undergo complete keratinization.

[Postmenopausal frontal fibrosing alopecia]

We report on two patients with postmenopausal frontal fibrosing alopecia. This recently described disease affects postmenopausal women and is characterized by progressive recession of the frontotemporal and parietal hair margins. It leads to a symmetrical band-like scarring area of alopecia 3-6 cm wide. Histological examination shows perifollicular fibrosis and lymphocytic inflammation concentrated around the isthmus and infundibular areas of the follicles. One of our two patients also had vulvar lichen sclerosus et atrophicus. An effective treatment for this type of postmenopausal alopecia is yet not known, but the course of the disease seems to be self-limited.

Impaired expression of stem cell factor in dermatofibroma fibroblasts

The number of mast cells is increased in dermatofibroma lesions and plays a role in the induction of fibrosis or its proliferation. We have investigated stem cell factor expression in solitary and multiple dermatofibromas by immunohistochemical straining. We also analyzed messenger RNA (mRNA) expression of stem cell factor in dermatofibroma tissues and cultured fibroblasts derived from dermatofibromas, using reverse transcriptase polymerase chain reaction. We found immunoreactive stem cell factor in keratinocytes, dermal fibroblasts, melanocytes and hair follicles. Unexpectedly, a reduced expression of immunoreactive stem cell factor in dermatofibroma fibroblasts was observed in solitary and multiple type. However, mRNA expression of stem cell factor was detected both in the dermatofibroma tissue and cultured dermatofibroma-derived fibroblasts. We speculate that the altered expression of stem cell factor of tumor cells in dermatofibroma lesions can be associated with the tumor cell proliferation and induction of dermatofibroma.

Successful treatment of chronic leg ulcers with epidermal equivalents generated from cultured autologous outer root sheath cells

The outer root sheath cells of hair follicles can substitute for interfollicular epidermal keratinocytes, as during healing of skin wounds when these cells migrate onto the denuded area and contribute to epidermal regeneration. Using improved culture techniques, we generated epidermal equivalents from cultured outer root sheath cells of patients suffering from recalcitrant chronic leg ulcers, primarily of vascular origin. In such epidermal equivalents, tissue organization as well as immunolocalization of epidermal differentiation products (keratin 10, involucrin, filaggrin) and integrins were indistinguishable from normal epidermis. As determined by the number of bromodeoxyuridine-incorporating cells, the basal layer contained a large compartment of proliferative cells irrespective of donor age. FACS analysis of the outer root sheath cells, used to prepare the epidermal equivalents, disclosed a fraction of small cells with enhanced expression of beta1-integrin, a potential stem cell marker. in contrast to acute wounds, a major definitive take of grafted cultured autologous keratinocytes has not been convincingly demonstrated in chronic wounds. In a pilot study, grafting of epidermal equivalents generated in vitro from autologous outer root sheath cells on 11 ulcers in five patients resulted in a definitive take rate of about 80%, with subsequent complete healing within 2 to 3 wk of five out of seven ulcers grafted with densely arranged cultures. This improvement in the treatment of chronic leg ulcers with cultured autologous keratinocytes probably depends on the large compartment of proliferative cells as well as on a well-developed horny layer which prevents disintegration of the grafts. Practical advantages of the new technique are its noninvasiveness, the lack of need for surgical facilities or anesthesia, and a short immobilization period after grafting.

Hair follicle involvement in herpes zoster: pathway of viral spread from ganglia to skin

Herpes zoster is caused by reactivation of varicella-zoster virus (VZV) persisting in dorsal root or trigeminal ganglia. To clarify the pathway of viral spread from the ganglia to skin, 16 biopsy specimens of early skin lesions of herpes zoster obtained from the face and trunk of 13 patients were studied histologically and immunohistochemically using monoclonal antibodies to the structural proteins of VZV. VZV-infected cells were detected in the hair follicles in 10 of the 16 specimens and in the epidermis in 2 specimens. Infected cells were localized in the isthmus of every involved follicle (12/12), frequently in the stem (8/10) and infundibulum (6/10), and never in the bulb. The high frequency of follicular involvement in herpes zoster suggests that VZV spreads to the area of skin innervated by myelinated nerves, which end around the isthmus of hair follicles and sebaceous glands.

Trichoblastic fibroma. A case report and an immunohistochemical study of cytokeratin expression

A 47-year-old woman noticed a nodule on her right shoulder that had been gradually increasing in size without symptoms. Histologic features of the biopsied nodule included round to irregularly shaped epithelial lobules demarcated by abundant sclerotic stroma located within the lower dermis and extending to the subcutis. The epithelial lobules consisted of cuboidal to columnar basaloid cells and were frequently arranged in narrow strands with many bifurcations and branching. Cystic structures containing lamellar keratinous material were occasionally found in connection with the lobules. The histologic findings were interpreted as trichoblastic fibroma. Immunohistochemical studies with antibodies directed against cytokeratins (CK) and involucrin revealed positive staining in most of the tumor cells with RCK102 and 34 beta E12 antikeratin antibodies, whereas the epithelial cords and the peripheral cells of the cystic structures stained with 170.2.14, 4.1.18, and CAM 5.2 antikeratin antibodies. However, CK1 or simple epithelial cytokeratins were not detected in any neoplastic elements. Based on comparative immunohistochemical findings in normal hair follicles, we propose that trichoblastic fibroma may first differentiate toward the outermost cell layer of the outer root sheath between the lower permanent portion and the upper transient portion and then into various other parts of the hair follicle.

Lymphomatoid papulosis and cutaneous CD30+ lymphoma

Lymphomatoid papulosis and cutaneous CD30+ lymphoma are closely related conditions in which large atypical lymphocytes that have similar immunophenotypic features occur. In lymphomatoid papulosis, the lesions are papules and nodules that spontaneously involute. There are two polar histologic patterns, type A and B, in which the large atypical cells resemble those of Hodgkin's disease and mycosis fungoides, respectively, but in many cases, features of both types are present, either separately or in the same lesions. Variants of lymphomatoid papulosis include cases with a perifollicular distribution and those with lymphocytic vasculitis or dermal mucin deposits. Clinical lesions that tend to be stable, a monomorphous cellular composition, and in the case of immunocompromised patients, the presence of Epstein-Barr viral genome characterize cutaneous CD30+ lymphoma. A loss of response to transforming growth factor-beta, which normally dampens cellular proliferation, may differentiate CD30+ lymphoma from lymphomatoid papulosis.

Hair cortex comedo

We report two cases of skin lesions that clinically resemble a comedo. Both lesions demonstrated a firm black papule which was histopathologically reminiscent of a dilated hair follicle associated with an abnormality of the hair cortex. These findings are thus considered to represent a unique and peculiar variant of the dilated pore of Winer, and the term "hair cortex comedo" is therefore believed to be suitable for such lesions.

Diffuse sebaceous gland hyperplasia. A case report and an immunohistochemical study with cytokeratins

We report a 43-year-old woman with sebaceous gland hyperplasia that occurred in a diffuse pattern of aggregated papular lesions involving her entire face, neck, and upper chest. Comedones, pustules, and inflammatory papules were absent. The eruption was accompanied by marked seborrhea. Histopathological examination showed enlargement of sebaceous acini, an increased number of immature sebocytes in foci, and a dilated follicular infundibulum. Immunohistochemical investigation showed cytokeratin 14 (CK 14) expression in the keratinocytes of the infundibulum, the isthmus, and sebaceous duct and in the mature and immature sebocytes; CK 17 expression in the keratinocytes of the sebaceous duct; CK 1 expression in the keratinocytes of the infundibulum; and an enhanced expression of the proliferation cell antigen Ki-67 (MiB1) in the immature sebocytes. With CK 18 and CK 19, no staining was observed. Oral therapy with isotretinoin (13-cis-retinoic acid) resulted in remarkable improvement in < or = 3 months. Histopathological and immunohistochemical examination after therapy showed markedly reduced sebaceous glands, a decrease in the staining of MiB1-positive immature sebocytes, and enhanced expression of CK 19 in immature sebocytes and sebaceous duct cells. Diffuse sebaceous gland hyperplasia is a rare variant of seboglandular proliferative disorders that is distinct from the well-known circumscribed type.

An objective measurement of the anchoring strength of anagen hair in an adult with the loose anagen hair syndrome

A 21-year-old male presented with the life-long symptom of slowly growing, easily extractable hair lacking sheath remnants. The distribution and density of all his hair regions appeared normal and there was no alopecia. A hair-pull test was painless and resulted in all hairs being removed, all in keeping with a diagnosis of loose anagen hair syndrome (LAHS). The trichogram was normal. Electronically measured epilation revealed values which were significantly lower than controls. His hair follicles were remarkable for this syndrome in that they looked perfectly normal with light microscopy; however, the segment of the follicle with the keratogenous zone was significantly shorter than normal. It is postulated that a subtle intercellular defect must reside in the line of shear proximal to the level of cuticular differentiation to account for the weak anchoring of the root in the follicle. A consequence of a genetic error probably causes both the weak anchoring and the slow hair growth.

Trichohyalin expression in skin tumors: retrieval of trichohyalin antigenicity in tissues by microwave irradiation

BACKGROUND

The antitrichohyalin antibody AE 15 is effective for identifying the cell lineage that undergoes the pathway of inner root sheath-type differentiation. Unfortunately, the AE 15 does not react with trichohyalin in tissue that is formalin-fixed and embedded in paraffin according to routine procedures.

METHODS

We attempted to retrieve the trichohyalin antigenicity in formalin-fixed, paraffin-embedded biopsy specimens that included normal skin as well as skin tumors such as trichofolliculoma and pilotricoma.

RESULTS

We found that the use of a metal solution in combination with microwave oven heating improves the trichohyalin immunoreactivity substantially. Further, trichohyalin was found to be expressed not only in the secondary hair structure in trichofolliculoma but also in a certain cell lineage that differentiates to squamoid cells in pilomatricoma.

CONCLUSIONS

Our findings established that surgical specimens processed under routine procedures can be successfully investigated with AE 15 using the microwave irradiation method. Studies of epidermal diseases expressing trichohyalin should provide valuable insights into our understanding the functional significance of trichohyalin during abnormal keratinization.

Benign cutaneous adnexal tumors with combined folliculosebaceous, apocrine, and eccrine differentiation. Clinicopathologic and immunohistochemical study of eight cases

Benign cutaneous adnexal tumors displaying divergent differentiation are rare, with very few well-documented cases reported in the literature. We describe eight cases of benign adnexal tumors showing a variable combination of eccrine, apocrine, and folliculosebaceous differentiation. Clinically, all tumors presented as solitary, slowly enlarging dermal or subcutaneous nodules located in the head and neck and the extremities. Histologically, they were characterized by well-circumscribed, unencapsulated nodules composed of a lobular proliferation of epithelial cells displaying a spectrum of trichogenic, sebaceous, apocrine, and eccrine differentiation. The histological spectrum included lobules and trabeculae of basaloid cells with glandular and ductal elements, well-formed folliculosebaceous units, primitive follicles, and foci of tricholemmal keratinization. Immunohistochemical evaluation in four cases showed similar cytokeratin, carcinoembryonic antigen, and epithelial membrane antigen staining profiles as those reported for sweat gland adenomas; in addition, focal S-100 protein positivity and GCDFP-15 positivity could also be demonstrated, suggesting eccrine-apocrine differentiation. The tumors were most frequently confused histologically with other adnexal neoplasms, including sebaceoma, sebaceous adenoma, basal cell carcinoma, chondroid syringoma, and trichoepithelioma. The present series highlights the capability.

Multiple pigmented follicular cysts: a subtype of multiple pilosebaceous cysts

Pigmented follicular cyst is a rare disorder which typically presents as a pigmented papule on the head or neck and which, histologically, exhibits terminally differentiated, pigmented hair shafts in an epidermoid cyst. We report a 22-year-old man with the multiple variant of this disorder. Clinically he had numerous brown-blue to flesh-coloured, domed-shaped papules, on the anterior chest and abdomen, of 10 years duration. Histologically, hybrid cysts exhibiting trichilemmal and epidermoid keratinization were seen. The cysts contained numerous pigmented, terminally differentiated hair shafts and, embedded in the wall of one cyst, was a sebaceous gland. The condition of multiple pigmented follicular cysts, is thought to represent a distinct subtype within the spectrum of multiple pilosebaceous cystic disorders.

Unilateral localized failure of beard growth

Hair may be classified by type as vellus or terminal. The transformation of vellus follicles into terminal follicles is induced by androgens in androgen-dependent areas by promoting the genetic program existing within individual follicles. Patients with normal androgen plasma levels and absent hair growth in certain areas under androgenic control have been described. One explanation of this condition may be abnormal target tissue sensitivity. We report a 17-year-old man whose only complaint was inability to grow a beard on the left side of his face.

A comparison of the culture and growth of dermal papilla cells from hair follicles from non-balding and balding (androgenetic alopecia) scalp

Male pattern baldness is a common, androgen-dependent skin problem in adult men which is not well understood, although androgens are believed to act on the hair follicle via the mesenchyme-derived dermal papilla situated in the middle of the hair follicle bulb. Since dermal papilla cells retain specific characteristics in culture, such as hair-growth promoting ability and appropriate features of the mechanism of androgen action, dermal papilla cells from follicles undergoing androgen-stimulated miniaturization may provide a useful in vitro model system. Therefore, dermal papilla cells have been derived from intermediate follicles from balding and nearly clinically normal sites of men with androgenetic alopecia. Balding dermal papillae were much smaller than non-balding ones and grew much less well under normal growth conditions. Supplementing the medium with human serum, rather than fetal calf serum, increased both the yield of established cultures and the number and health of the dermal papilla cells produced. Non-balding cells also grew faster in human serum. Balding cells retained the normal fibroblastic shape and aggregative behaviour of dermal papilla cells, but always grew less well than non-balding cells. Nearly clinically normal dermal papillae were similar, or slightly smaller, in size to non-balding ones, but their growth resembled balding cells. Since balding dermal papilla cells can be cultured, though with much greater difficulty than nonbalding ones, and exhibit differing growth characteristics to non-balding cells, they merit further investigation which may increase our understanding of, and ability to control, androgenetic alopecia.

Hair follicle nevus: case report and review of the literature

The study of hair follicle tumors can be confusing, and hair follicle nevi are no exception. Analogous lesions frequently have divergent appellations. We evaluated the English-language literature on hair follicle nevi and histologic equivalents from 1921 to 1994. In addition, we reviewed four standard dermatopathology textbooks for further examples. We found 20 published valid cases of hair follicle nevi. Two of the cases were called congenital vellus hamartoma. Hair follicle nevi are rare, benign, often congenital hamartomas composed of multiple vellus hairs. They are typically on the face. We present an infant girl with a hair follicle nevus and review the histologic features and nomenclature of the lesion.

Acquired pili torti--a structural hair shaft defect in anorexia nervosa

The hair of seventeen girls aged 13 to 19 years with anorexia nervosa (AN) was studied and compared with the hair of fifteen healthy girls aged 13 to 18 years with no complaints of hair loss but with similar habits of hairstyling and care. Light microscopic examination of the hair revealed no defect in the control group. In the AN group, fourteen patients (82.3 percent) had pili torti, an acquired hair shaft defect that has not yet been described in association with this disease. We estimate that the hair defect was due to malnutrition combined with ingestion of exaggerated amounts of yellow vegetables and vitamin supplements, causing a significant increase in levels of serum carotene, retinyl esters, retinol, and retinoic acid. We suggest a possible link between excess vitamin A and pili torti in patients with AN.

Flesh-coloured micropapules on the face and upper trunk

The following case report is of a 49 year old man who presented with a 20 year history of small asymptomatic flesh coloured firm papules which were concentrated on his face, neck and upper trunk. The diagnosis of multiple fibrofolliculomas of the familial type was reached.

Hair follicle nevus: case report and review

Hair follicle nevus has been variously defined as a specific type of neoplasm with follicular differentiation or as a synonym for trichofolliculoma; the latter view has predominated in recent years. We report a nodular lesion that was identified histopathologically as a hamartoma with follicular differentiation and that systematic serial sectioning showed not to be a trichofolliculoma. After reviewing previous descriptions of lesions diagnosed as hair follicle nevus, and in the light of our own observations, we believe that hair follicle nevus is a distinct type of adnexal hamartoma.

Folliculosebaceous cystic hamartoma with perifollicular mucinosis

An 8-year-old boy had a congenital, solitary verrucous lesion on his ear that histologically showed numerous maloriented infundibulocystic structures from which radiated immature sebaceous lobules as well as hair germs with rudimentary papillae. The surrounding stroma was fibrillary, containing large quantities of mucin. We conclude that perifollicular mucinosis, considered to be specific to Carney's syndrome, can also be observed in solitary folliculosebaceous hamartoma.

Loose anagen hair in hypohidrotic ectodermal dysplasia

We report a 4 year-old boy affected with hypohidrotic ectodermal dysplasia in whom loose anagen hair syndrome (LAHS) was suspected clinically. The diagnosis was confirmed by examination of hair by optic and scanning electron microscopy. Loose anagen hairs have not been previously described in the ectodermal dysplasias. It is possible that our patient had real LAHS or an ectodermal dysplasia with loose anagen hair as an epiphenomenon.

Measurement of apoptotic fragments in growing hair follicles following gamma-ray irradiation in mice

The usefulness of apoptotic fragments assay for investigating radiation response of hair follicles was examined. Frequency was defined as the ratio of the total number of apoptotic fragments to the number of hair follicles per section examined. The curve of dose-effect relationship for the data of apoptotic fragments was obtained by fitting the linear-quadratic model y= a+bD+cD2. When plotting on a linear scale against radiation dose, the line of best fit was y= 0.549 +/- 1.775) + 3.578 +/- 1.236)D + (-0.124 +/- 0.139)D2. The dose-response curves were linear-quadratic and a significant relationship was found between the frequency of apoptotic fragments and dose. The morphological findings of the irradiated groups were typical apoptotic fragments in the matrix region of hair follicles, but the spontaneous occurrence of apoptotic fragments was not observed. Since the apoptotic fragments was not observed. Since the apoptotic fragment assay is simple and reproducible in the whole body irradiation range of 0.5 to 8 Gy, it may be a good tool for evaluating the dose response of low dose radiation in vivo and provide a potentially valuable biological dosimeter for dose distribution determinations following accidental exposure.

Merkel cells in nevus sebaceus. An immunohistochemical study

Nevus sebaceus, considered to be a hamartoma, is known to develop several secondary hyperplastic and neoplastic proliferations. By the use of immunohistochemical studies, we were able to describe a sometimes very striking increase of Merkel cells in nine of 19 nevi sebacei. Only nevi sebacei that formed follicular germ structures and trichoblastomas showed a Merkel cell hyperplasia. In the hyperplastic epidermis of some cases a slight hyperplasia of singular Merkel cells was observed. In foci with follicular germs and trichoblastomas, however, the Merkel cells were much more abundant and sometimes arranged in clusters. Merkel cell hyperplasia is likely to represent another facet of hamartomatous hyperplasia in nevi sebacei. Our observation that trichoblastomas in nevus sebaceus possess, as a rule, hyperplasia of Merkel cells, might be an additional aid to distinguish these tumors from basal cell carcinomas, which are usually devoid of Merkel cells. Furthermore, our findings are a hint that development of follicular germs and trichoblastomas in nevi sebacei may be promoted by Merkel cells.

[Hair-like hyperkeratoses in patients with kidney transplants. A new cyclosporin side-effect]

We report a 31-year-old renal transplant patient treated with cyclosporin A who developed an unusual sebaceous gland hyperplasia accompanied by a disseminated follicular spiny hyperkeratosis. Those alterations were most evident on his face and limbs. In some locations hairy hyperkeratosis with authentic hair neogenesis was found. The histology of these alterations showed a marked hyperkeratosis of the hair follicles with formation of hair-like spikes either alone or in connection with hairs. The presence of true hairs distinguishes our case from the morphologically similar disseminated spiked hyperkeratosis and other spiny keratinization disorders. Scanning electron microscopy helped to demonstrate the hair-like structure of these keratoses. Some of the sebaceous glands showed cystic widening of their lumina, which were filled with abundant amorphous eosinophilic material, a finding similar to earlier observations. Our case demonstrates that these skin alterations should be classified as side effects of cyclosporin A and that they are apparently dose-dependent.

Tumor of the follicular infundibulum: a clinicopathologic study

BACKGROUND

Tumor of the follicular infundibulum (TFI) is a rare benign adnexal tumor that has characteristic histopathologic features.

OBJECTIVE

Our purpose was to describe the clinical and pathologic features of 12 patients with TFI.

METHODS

Of 121,500 cutaneous biopsy specimens recorded between 1981 and 1993, all TFIs were identified and examined by conventional microscopy. The clinical and histologic findings were compared with those of previously published cases.

RESULTS

Of the 12 patients, seven had a solitary tumor, two had eruptive TFI involving the face, and three TFIs were incidentally discovered in association with nevus sebaceus or fibroma. TFI-like changes were also observed in the wall of a hybrid cyst. The most discriminating features of TFI were the horizontal platelike organization of the tumor and the dense elastic network beneath the tumor. Of the different forms of TFI, only eruptive tumors can be clinically identified because they are small hypopigmented macules.

CONCLUSION

We classify TFIs as (1) solitary tumors, (2) eruptive tumors, (3) TFI associated with other lesions of Cowden's disease, (4) TFI associated with a single tumor such as nevus sebaceus, and (5) TFI-like epidermal changes.

Localization of intercellular adhesion molecule-1 in middle ear cholesteatoma

Intercellular adhesion molecule-1 (ICAM-1) may have a role in acquired cholesteatoma, which is usually associated with an inflammatory reaction occurring in the middle ear cavity. The presence of ICAM-1 in human cholesteatomas was demonstrated by an immunoblotting assay using a specific monoclonal anti-ICAM-1 antibody after protein extraction. Distribution of ICAM-1 in the cholesteatoma tissues was then studied by avidin-biotin-peroxidase complex staining. ICAM-1 appeared to be localized on keratinocytes in all layers of the epithelium and on Langerhans cells in both the epithelium and granulation tissue of cholesteatoma. ICAM-1 was not found in the epidermis of normal external ear canal skin, normal tympanic membrane or normal facial skin, but significant staining was seen on keratinocytes of hair follicles and glands in the facial skin. The present study is the first to demonstrate ICAM-1 in cholesteatoma and suggests that it may have an important role in the clinical development of cholesteatoma, including migration, adhesion and proliferation of lymphocytes, Langerhans cells and keratinocytes.

Histopathologic findings in the clinically uninvolved skin of patients with mycosis fungoides

Several of the methods of treating plaque-stage mycosis fungoides (MF) advocate treatment of the whole skin, although relatively little information exists on the histologic appearance of clinically uninvolved MF skin. Our study was performed to elucidate the histologic appearance of the clinically uninvolved skin of plaque-stage MF patients. Biopsies were taken from the clinically uninvolved skin of 18 untreated patients with plaque-stage MF, 1 cm (near) and > or = 10 cm (far) from the MF plaques, and from 23 normal, healthy controls. Eight to 12 serial sections from each specimen were examined. The most common histologic finding, which was observed in six (33%) biopsies of near skin and four (22%) biopsies of far skin compared with only one (4%) biopsy of normal control (p = 0.02 and 0.1, respectively), consisted of mononuclear-cell infiltrate around a blood vessel in the papillary dermis, with extension of some of these cells into the overlying epidermis. More diffuse and epidermotropic mononuclear cell infiltrates were seen in an additional three (17%) biopsies of near skin, whereas mild nonepidermotropic superficial perivascular or perifollicular mononuclear cell infiltrates were observed in an additional four (17%) biopsies of the normal controls. In conclusion, the most common histologic finding in our study, which was observed predominantly in the MF group, might represent an earlier stage and clinically undetectable involvement of the normal-looking skin in MF patients.

Merkel cells are integral constituents of desmoplastic trichoepithelioma: an immunohistochemical and electron microscopic study

The incidence of Merkel cells has previously been investigated in a number of inflammatory and tumorous lesions of the skin. Special attention was given to tumors with follicular differentiation. In the present study we examined the localization of Merkel cells in another adnexal tumor, the desmoplastic trichoepithelioma (n = 15), as well as in its main differential diagnosis, the morpheiform basal-cell carcinoma (n = 30). Using immunohistochemical methods, we found Merkel cells as a stable constituent in desmoplastic trichoepitheliomas, but failed to detect them in morpheiform basal-cell carcinomas. These findings might therefore be an important tool in the sometimes very difficult but clinically imperative distinction between these two conditions. Furthermore, our study may be of interest in the discussion about the origin of desmoplastic trichoepitheliomas. High numbers of Merkel cells in desmoplastic trichoepitheliomas indicate a bulge-derived origin of this adnexal tumor, since high numbers of Merkel cells, especially in the bulge, were recently discovered. Although the significance of Merkel cell hyperplasia in desmoplastic trichoepithelioma is not presently understood, a regulatory role of the Merkel cell in growth and development of this adnexal tumor is suggested.

Basaloid folliculolymphoid hyperplasia with alopecia as an expression of mycosis fungoides (CTCL)

Follicular mucinosis, papules, cysts and comedones have been previously described as expressions of follicular involvement by mycosis fungoides. We report a patient with mycosis fungoides who developed extensive alopecia. Multiple scalp biopsies showed perifollicular and intrafollicular infiltrate of lymphocytes but no evident follicular mucinosis. On transverse sections many of the follicles showed an absence of differentiation towards hair sheath, canal, sebaceous gland or hair formation, but instead formed undifferentiated basaloid structures. These basaloid structures showed transition from atrophic telogen follicles to hypertrophic basaloid islands infiltrated by lymphocytes, resembling the pattern previously described in cutaneous lymphadenoma. Immunophenotyping showed a predominance of helper T-cells which, on ultrastructural examination, showed cerebriform nuclei. The unusual histological findings in our case may be analogous to the hyperplasia seen in sweat glands in syringotropic mycosis fungoides (syringolymphoid hyperplasia), and we propose the term basaloid folliculolymphoid hyperplasia to describe this feature. Basaloid follicular hyperplasia has been previously described as a component of follicular mucinosis but may apparently develop in the absence of overt mucinosis.