Follicular Infundibulum Research Articles

Cornoid lamellae associated with follicular infundibulum and acrosyringium in porokeratosis

Skin lesions of porokeratosis consist of an atrophic center bordered by a peripheral grooved keratotic ridge that corresponds histopathologically to the cornoid lamella. Originally porokeratosis was named based on the assumption that the columns of parakeratosis emerge from the ostia of eccrine ducts. Despite this, it is generally accepted that the cornoid lamellae are rarely related to the acrosyringium. We recently encountered two cases of porokeratosis, where the cornoid lamellae were related to the follicular infundibulums. Therefore, we analyzed the location of the cornoid lamellae in 86 lesions of porokeratosis from 73 patients from our archives. We found that many cornoid lamellae are also detected at follicular infundibulum and acrosyringium. The existence of so many cornoid lamellae at follicular infundibulum and acrosyringium inside the plaques cannot be explained by pure coincidence and may be more than fortuitous.

Demodicosis: A clinicopathological study

Demodex mites are common commensal organisms of the pilosebaceous unit in human beings and have been implicated in pityriasis folliculorum, rosacea-like demodicosis, and demodicosis gravis. We sought to describe the spectrum of clinicopathological findings and therapeutic responses of demodicosis in Taiwanese patients. We conducted a retrospective study to review clinicopathologic findings and therapeutic responses of 34 cases of diagnosed demodicosis. Fifteen cases with positive results of potassium hydroxide examination, standardized skin surface biopsy specimen, and/or skin biopsy specimen, and resolution of skin lesions after anti-Demodex treatment were included for final analysis. Nineteen cases were excluded because of insufficient positive data to make a definite diagnosis. There were 4 male and 11 female patients (age 1-64 years, mean age 38.7 years). The disease was recurrent or chronic with a duration ranging from 2 months to 5 years (mean 15.7 months). The skin lesions were acne rosacea-like (n = 8), perioral dermatitis-like (n = 5), granulomatous rosacea-like (n = 1), and pityriasis folliculorum (n = 1). Skin biopsy was performed in 7 patients. Overall, the histopathology was characterized by: (1) dense perivascular and perifollicular lymphohistiocytic infiltrates, often with abundant neutrophils and occasionally with multinucleated histiocytes; (2) excessive Demodex mites in follicular infundibula; and (3) infundibular pustules containing mites or mites in perifollicular inflammatory infiltrate. The skin lesions resolved after treatment including systemic metronidazole, topical metronidazole, crotamiton, or gamma benzene hexachloride. Small sample size and a fraction of patients without long-term follow-up are limitations. Demodicosis should be considered in the differential diagnosis of recurrent or recalcitrant rosacea-like, granulomatous rosacea-like, and perioral dermatitis-like eruptions of the face. Potassium hydroxide examination, standardized skin surface biopsy, skin biopsy, or a combination of these are essential to establish the diagnosis.

Máculas hipopigmentadas vitiligóides e tumor do infundíbulo folicular

Tumor of the follicular infundibulum is an uncommon cutaneous lesion with different forms of clinical presentation, namely solitary and multiple/eruptive variants. The former shows predilection for head and neck and presents as a papulonodular scaly tumor. The latter is less frequent and occurs on facial, neck and upper chest areas as brown, reddish or more commonly hypopigmented macules leading to the differential diagnosis with vitiligo. The different clinical forms share the same histopathologic aspect. The present report describes a case of the multiple variant of tumor of the follicular infundibulum disclosing facial vitiligoid macules in a 35-year-old male patient.

Multiple clear cell trichoblastoma

Clear cell trichoblastoma is a very rare neoplasm with follicular differentiation described recently. Only three cases of clear cell trichoblastoma were reported in literature and all of them were presented as single lesion. Here, we report a case of clear cell trichoblastoma with multiple lesions in a child. Two biopsies from the patient showed that the neoplasm was located in the dermis, and step sections showed that they were connected with the follicular infundibulum. The neoplasm was almost made of clear cells that had clear cytoplasm and eccentrically disposed nucleus. At the periphery of the neoplasm, the clear cells showed palisade array with the nucleus at the pole opposite the thick basement membrane, and only a few basal cells were located at the periphery of the neoplasm. Periodic acid-Schiff stain was almost negative in the clear cells. Immunohistochemistry studies showed the neoplasm stained positive for AE1/AE3 but negative for CAM 5.2, cytokeratin 7, cytokeratin 20, epithelia antigen, carcinoembryonic antigen, epithelial membrane antigen, androgen receptor, S-100 and CD34. The clinical and histopathological characters suggested the diagnosis of multiple clear cell trichoblastoma. After 20 months' follow up, the lesions of the patient showed incomplete regression, which is a rare phenomenon in neoplasm with follicular differentiation.

Pênfigo foliáceo em cabra Boer

Pênfigo foliáceo é uma doença auto-imune crônica da pele observada com freqüência em cães e, com menor freqüência, em outras espécies animais. Neste trabalho é descrito um caso desta enfermidade no semi-árido da Paraíba, em uma cabra da raça Boer, que apresentava lesões crônicas de pele com extensas áreas alopécicas irregulares, esfoliativas, com crostas amareladas e bilaterais que afetavam a região dorsal da escápula, do tórax, do dorso, da parede do abdominal, da garupa, dos membros pélvicos e da cauda. No rodete coronário, havia espessamento da pele e lesões crostosas. Microscopicamente foram observadas hiperqueratose, espongiose e pústulas intracorneais ou subcornais afetando epiderme e infundíbulos. Nas pústulas, havia grande quantidade de neutrófilos, eosinófilos e células acantolíticas. Na derme, havia acentuada congestão e moderado infiltrado inflamatório composto por eosinófilos, raros plasmócitos, linfócitos e macrófagos, principalmente na periferia de capilares e nos folículos pilosos. Os achados macro e microscópicos são característicos de pênfigo foliáceo. Esta enfermidade é rara em caprinos e, provavelmente, este seja o primeiro relato da doença no Brasil.

Basal Cell and Squamous Cell Carcinoma Occurring within a Field of Multiple Tumors of the Follicular Infundibulum

Basal Cell and Squamous Cell Carcinoma Occurring within a Field of Multiple Tumors of the Follicular Infundibulum

Basal Cell and Squamous Cell Carcinoma Occurring within a Field of Multiple Tumors of the Follicular Infundibulum

Basal Cell and Squamous Cell Carcinoma Occurring within a Field of Multiple Tumors of the Follicular Infundibulum

The 2 Clinical Subbands of the Distal Nail Unit and the Nail Isthmus. Anatomical Explanation and New Physiological Observations in Relation to the Nail Growth

The distal region of the nail unit, which marks the transition of the nail bed to the hyponychium, is known clinically as the onychodermal band (ODB). For several authors, the ODB is described as 2 subbands of tonal values: slightly milky and pink from proximal to distal. However, its 2 subbands show individual variation and are often scarcely visible. It has been stated that the proximal subband, that is, the white band of Pinkus, corresponds histologically to the attachment of the compact orthokeratotic layer of the hyponychium to the nail plate. In 2 studies, I have individualized a transitional zone between the nail bed and the hyponychium: the nail isthmus. In these previous studies, the ODB was not visible. The purpose of this article is to analyze the anatomo-clinical correlations between the nail isthmus and the ODB and to highlight some new physiological information concerning the nail growth. A case showing clearly the 2 clinical subbands of ODB was investigated. In addition, all the longitudinal sections of the 5 normal nail unit specimens, used in the 2 previous studies, were reviewed to analyze the ventral surface of the nail plate in longitudinal planes. The nail isthmus can be described synthetically by 2 features: (1) a stair-like appearance of the epithelium of the distal nail bed with a marked depression of the epithelium below the inferior surface of the nail plate (2) a specialized mode of attachment of its horny layer to nail plate via a horizontal mode of differentiation. The white band of Pinkus corresponded histologically to the nail isthmus. Its white color was caused by alteration in light diffraction in the thin compartment of pale parakeratotic corneocytes squeezed between the nail plate and the epithelium of the nail isthmus. The pink middle band corresponded to the 2 horny layers surmounting the epidermis of the hyponychium: the compact horny layer of the hyponychium and the thin pale "tongue-like" parakeratotic extension of the nail isthmus. The variable thinness of both the suprapapillary plates of hyponychium and the 2 horny layers surmounting this area explained the variable visibility of the well-developed vascular network of the dermal papillae of hyponychium, that is, the variegation of the middle subband. The review of all step sections of the normal distal nail unit cut longitudinally showed that the ventral surface of the nail plate was slightly serrated in longitudinal planes. The nail isthmus belongs functionally to the nail bed. The strong adherence between the nail plate and the nail bed is replaced by an effective sealing between the thin pale tongue-like parakeratotic extension of the nail isthmus and the nail plate. In contrast, the hyponychium belongs functionally to fingertip and exhibits an epidermal-type horny layer, that is, the horny layer of the distal hyponychium is a supportive structure. As the ventral surface of the nail plate is undulated in its transversal and to a lesser extend in its longitudinal axis, the nail bed and the nail plate grow forward together. The nail plate is "pushed" out by 2 factors: (1) the matrix which makes a new plate, (2) the nail bed which moves slowly, parallel to the direction of the nail growth, toward the tiny grooves and ridges of the inferior border of the nail plate. According to the anatomo-clinical description of the distal nail unit, the nomenclature of this region could be simplified. The term nail isthmus should be proposed as equivalent of the white band of Pinkus. The hyponychium could be compared with the follicular infundibulum as a zone bordering the surrounding epidermis, and the term nail infundibulum could be considered to be synonymous for hyponychium and ODB.

Human papillomavirus infection and ultraviolet light exposure as epidermoid inclusion cyst risk factors in a patient with epidermodysplasia verruciformis?

Epidermoid inclusion cysts are common lesions with unclear etiology. We sought to examine evidence for human papillomavirus (HPV) infection and ultraviolet light (UV) exposure as risk factors in the formation of epidermoid inclusion cysts. We performed HPV typing of biopsied cysts with polymerase chain reaction for a patient with darkly-pigmented skin, epidermodysplasia verruciformis (EV) and more than 250 photodistributed cysts. HPV types 8 and 6 DNA was demonstrated within biopsy specimens of 3 cysts. In one biopsy specimen, abnormal keratinocytes bridging the follicular infundibulum were seen. We concluded that UV exposure and HPV viral infection may be risk factors for the formation of epidermoid inclusion cysts.

A tumor of follicular infundibulum in 81-year-old healthy female: A unique case report

A tumor of follicular infundibulum in 81-year-old healthy female: A unique case report

Metastasizing Adenocarcinoma and Multiple Neoplastic Proliferations Arising in a Nevus Sebaceus

Nevus sebaceus of Jadassohn is a hamartoma of multiple skin structures. Many neoplasms have been reported to arise in association with nevus sebaceus, most commonly trichoblastoma/basal cell carcinoma and syringocystadenoma papilliferum. We report a case of a 66-year-old woman with an adenocarcinoma as well as multiple neoplastic proliferations arising in a long standing nevus sebaceus on the scalp, with subsequent occipital neck metastatic disease. On histologic evaluation, the epidermis showed changes reminiscent of tumor of the follicular infundibulum as well as basaloid proliferations resembling superficial trichoblastoma. A focus suggestive of syringofibroadenoma was also present. A small dermal collection of basaloid and more mature sebocytes was consistent with a sebaceoma/sebaceous epithelioma. Most of the lesion was composed of an adenocarcinoma with areas showing ductal differentiation with decapitation secretion, well-formed papillae and focal cribriform structures. Other portions demonstrated a high-grade neoplasm with prominent nuclear atypia and a solid pattern of growth resembling high-grade breast carcinoma. Anti-epithelial membrane antigen strongly labeled tumor cells and highlighted ductal structures. Less than 1% of cells expressed progesterone or estrogen receptors. Her2/neu reactivity was focally present, showing 1+ membranous reactivity in 10% of cells. Anti-p63 labeled basaloid cells surrounding the tumor lobules. A breast primary was ruled out by clinical and radiologic examination. This report illustrates an extraordinary case of adnexal neoplasia displaying various lines of differentiation arising in association with nevus sebaceus.

Dry dermoscopy in clinical treatment of alopecia areata

Although dermoscopy is conventionally utilized with immersion gel for diagnosis of pigmented tumor, we utilized dry dermoscopy, which is dermoscopy without immersion gel, for clinical treatment of alopecia areata (AA). The scalp skin and hair of a 38-year-old Japanese male, and 23-, 22- and 47-year-old Japanese females with AA, whose normal hair color was black, were examined by dry dermoscopy. Exclamation mark hairs, short hairs, fractured hairs and black dots, all characteristic of AA, were detected by dry dermoscopy of the scalp of the 23-year-old female with ophiasis type AA. In the case of the 47-year-old female with round hair loss on the occipital scalp and diffuse hair loss over the fronto-vertical region, dry dermoscopy was useful for diagnosis of AA based on hair characteristic of AA. After she received corticosteroid pulse therapy with 500 mg of i.v. methylprednisolone on 3 successive days, her hair showed apparent regrowth and disappearance of the abnormal hairs characteristic of AA, evidenced by dry dermoscopy 1 month later. In a case of long-lasting AA in the 23-year-old female, we found a follicular plaque-like appearance at the opened hair follicle pores by dry dermoscopy. Histopathologically, the incompletely differentiated remnant hair shaft was packed in the follicular infundibulum. In addition, regrowing vellus hairs, which were difficult to clinically recognize, were detected by dry dermoscopy. Dry dermoscopy is therefore useful for both diagnosis and follow up of AA.

Pseudoepitheliomatous hyperplasia – an unusual reaction following tattoo: report of a case and review of the literature

A 59-year-old woman presented with an itchy and uncomfortable raised lesion at a tattoo site (Fig. 1) on the lateral aspect of the left leg, just above the ankle. The tattoo had been placed 2 years before her presentation and the tattoo site was sun exposed. Immediately after she had the tattoo, she noticed redness of the skin. After a week, a pruritic and red scaly nodule developed that continued to gradually enlarge until her presentation. The patient had tried topical vitamin A and D ointment with no relief. The patient also had tattoos on the arms without any noticeable skin changes. The patient reported that the tattoo procedure on her leg was more painful than that on her arms, and was performed by a different (and perhaps inexperienced) tattoo artist. The original tattoo contained red, green, and yellow pigments. A diagnosis of tattoo granuloma was considered; squamous cell carcinoma and fungal infection were included in the differential diagnosis. A punch biopsy was performed, followed by complete surgical excision of the lesion with a split-thickness skin graft from the right thigh. The skin excision specimen showed a 3 x 2.5-cm granular and pitted pink lesion with well-demarcated, somewhat irregular borders. The lesion was raised 0.5 cm above the skin surface. The lesion was present in the center of the original tattoo. Portions of the original tattoo with green and blue-green pigmentation were visible on either side of the lesion. No satellite lesions were identified. Microscopically, the raised lesion demonstrated striking pseudoepitheliomatous hyperplasia, with irregular acanthosis of the epidermis and follicular infundibula, hyperkeratosis, and parakeratosis (Fig. 2). Follicular plugging was present with keratin-filled cystic spaces. There was a brisk mononuclear inflammatory infiltrate in the dermis, composed primarily of lymphocytes, with admixed plasma cells and histiocytes. Giant cells were occasionally identified. Dermal pigment deposition was noted both within the lesion and in the surrounding skin, corresponding to the original tattoo. Variable dermal fibrosis was noted, with thick collagen bundles in some areas. There was no evidence of epidermal keratinocytic atypia, dyskeratosis, or increased suprabasal mitotic activity. Special stains (periodic acid-Schiff and acid-fast) for microorganisms were negative.

Tubular Adenoma and Syringocystadenoma Papilliferum: A Reappraisal of Their Relationship. An Interobserver Study of a Series, by a Panel of Dermatopathologists

Tubular adenoma (TA) and syringocystadenoma papilliferum (SCAP) may show histopathological overlap, with some lesions having features of both neoplasms (SCAP + TA). TA has been recently suggested to represent a carcinoma. Four observers blindly assessed 67 cases of TA, SCAP, and their lookalikes (poroma, apocrine adenoma, apocrine carcinoma; all lesions focally featuring a pseudopapillary pattern), and classified the lesions into one of four categories: (1) TA, (2) SCAP, (3) SCAP + TA, and (4) others. Lesions were also classified as benign or malignant. In only 29 cases was there unanimous agreement among the four observers, who classified 22 lesions as TA, three as SCAP, and four cases as others. Of the 38 cases where there was interobserver diagnostic variation, in 30, the diagnosis varied between TA or SCAP or SCAP + TA; the remainder fell in the others category. Analysis of the factors leading to interobserver variability indicated that diagnostic problems occurred when there were any of the following: epidermal acanthosis, papillomatosis, connection of the neoplastic tubules to the overlying epidermis and/or follicular infundibula, and plasma cell infiltration. These features accounted for the morphological overlap between TA and SCAP. All observers agreed that the lesions were benign; the only apocrine carcinoma included was recognized as such by all observers. From the study, it was concluded that TA may arise in the deep dermis without any epidermal connection, or, in other cases, it may be more superficially located with or without an epidermal connection. It may be reasonably inferred that, possibly as a response to infection, there may be accompanying plasma cells and variable acanthosis and papillomatosis, such that the appearances are those of "pure" SCAP, or lesions may have features "intermediate" or overlapping between TA and SCAP.

이주에 생긴 단발성 섬유모낭종 1예

Fibrofolliculoma is a rare benign follicular neoplasm in pilar complex, histopathologically characterized by hyperplastic follicular infundibulum with a central keratinous plug, and anastomosing strands of basaloid cells branching into dense surrounding stroma. Fibrofolliculoma is benign skin tumor with the following features, multiple growths, autosomal inheritance, and associated skin lesions, while solitary form with identical clinical and microscopic features are relatively rare and nonhereditary. We report on a 41-year-old man with a solitary, bean sized mass on his left tragus which histopathologically shows a typical fibrofolliculoma. (J Clinical Otolaryngol 2007;18:122–124)

Functional significance of non-neuronal acetylcholine in skin epithelia

In recent years, the physiological role of non-neuronal acetylcholine (ACh) and its receptors (AChR) in epidermal physiology has been under intense investigation. However, little is known about the role of the non-neuronal cholinergic system in inflammatory skin diseases. We chose the clinically nicotine-dependent skin disease hidradenitis suppurativa (HS) as model to study the influence of long term nicotine ingestion on epidermal morphology and AChR expression. HS is a chronic inflammatory, disabling disease of unknown pathogenesis emerging from the pilosebaceous unit of the intertriginous areas. In order to correlate our findings to specific nicotine effects, we used the organotypical coculture system (OTC) and raised artificial epidermis in the presence of nicotine. After 12 days in culture control OTC showed a mature epithelium, while nicotine treated OTCs were significantly thicker. Using immunofluorescence analysis, nicotine treated OTCs produced significantly stronger immunoreactivity (IR) for the α3, M3 and M5 AChR antisera than control. In contrast, the α7 nAChR antiserum showed a slightly reduced IR in the granular layer and the α9 nAChR IR retracted to the lower suprabasal layers. In HS epidermis we found the strongest IR for all AChR around the follicular infundibulum while in the sinus epithelia it was only weak. In contrast to the nicotine treated OTC, the α7 nAChR IR in the hyperplastic HS epidermis was clearly extended to all living layers. Altogether we provide first hints for a causative role of the non-neuronal cholinergic system in the pathogenesis of HS by promoting infundibular epithelial hyperplasia and thus follicular plugging.

Squamous Eddies in Irritated Seborrheic Keratosis

Seborrheic keratosis is related to the intraepidermal hair follicle in its morphogenesis. Squamous eddies in irritated seborrheic keratosis (ISK) are known to develop by focal maturation of basaloid cells, but the significance of squamous eddies is not understood. The purpose of this study was to elucidate the nature of squamous eddies in ISK. Serial sections of paraffin blocks of 20 cases of ISK were examined. We tracked each squamous eddy through the serial sections to observe the different shapes and positions of the same squamous eddy. In 4 cases, squamous eddies revealed hair shafts at their centers in different sections. In 14 cases, squamous eddies contained acrotrichial canals. In 13 cases, squamous eddies were connected to keratotic invaginations we thought to be follicular infundibula. Eighteen of the 20 cases of ISK showed at least 1 of the morphological features of intraepidermal hair follicle structures. We have found that the squamous eddies of ISK are anatomically related to acrotrichia.

Quantitative research on skin pore widening using a stereoimage optical topometer and Sebutape®

The treatment of skin pore widening is concerned with cosmetics sciences, but an objective and quantitative measurement method of the severity of skin pore widening has not been developed. In this study, bioengineering methods were applied to evaluate skin pore widening. The results from bioengineering measurements were compared with clinical visual assessment. In order to quantify skin pore widening, three-dimensional data of skin pore were produced by a stereoimage optical topometer (SOT). The sizes of follicular infundibulum were measured quantitatively, with reserved sebum by Sebutape. 50 female volunteers were divided into two groups. Group A was tested by the cosmetics including active ingredient and group B by placebo. The constricting effect of skin pores by cosmetics was measured for immediate effect and long-term effect. In the immediate effect, there was no statistical difference between groups A and B in visual scoring. In SOT, the size of the skin pores of group A had changed after application of cosmetics but there were no changes in group B. In the long-term effect, there was no statistical difference between groups A and B in visual scoring. TA, TV, SA, and SV of skin pores of groups A and B were decreased in 3 and 6 months by SOT. In Sebutape measurement, there was decreased volume of reserved sebum in groups A and B. The result of the Sebutape study was similar to that of SOT. Evaluation of skin pore change by visual assessment is difficult, but bioengineering tools are more reliable and useful methods for the assessment of skin pore change.

Angiolymphoid hyperplasia with follicular mucinosis

Follicular mucinosis occurring along with angiolymphoid hyperplasia with eosinophils (ALHE) has been described in a 54-year-old female. The patient presented with pruritic erythematous papules on the left frontoparietal scalp. Histopathological examination showed prominent blood vessels in the dermis lined by plump histiocytoid endothelial cells that were surrounded by a dense lymphoid infiltrate with numerous eosinophils; these findings are typical of angiolymphoid hyperplasia with eosinophils. Features of follicular mucinosis were observed in the same section with several hyperplastic follicular infundibula containing pools of mucin in the infundibular epithelium. The concurrent occurrence of these two distinct histopathological patterns in the same biopsy specimen has been described in only three cases to date.

Follicular Germinative Cells in Pilomatricoma

Pilomatricoma is a follicular neoplasm that shows differentiation towards the follicular matrix, as characterized by matrical cells and shadow cells. In addition, this is sometimes accompanied by differentiation toward the follicular infundibulum and outer root sheath. These finding suggest that pilomatricoma can subtly differentiate towards any structure of the follicle. However, morphologically, no distinct germinative cells resembling embryonic follicular germ cells have been found in pilomatricoma to date. We report on two cases of pilomatricoma in which distinctive follicular germinative cells palisaded at the edges of collections of matrical cells. We propose two explanations: one is that the metrical cells of pilomatricoma can focally de-differentiate to form follicular germinative cells, and the other is that these follicular germinative cells are the precursor cells of pilomatricoma.