CD34 expression in human hair follicles and tricholemmoma: a comprehensive study

CD34 and BerEP4 Are Helpful to Distinguish Basaloid Tricholemmoma From Basal Cell Carcinoma

Tricholemmoma, a benign follicular neoplasm with outer root sheath differentiation, typically comprises clear or pale cells, and when multiple is pathognomic of Cowden's syndrome. The tumor is probably underrecognized and in basaloid examples can be difficult to distinguish from basal cell carcinoma (BCC). We studied 55 tricholemmomas (including 15 basaloid cases) and compared immunohistochemical profile with nodular BCC from our archives. Basaloid and non-basaloid tricholemmomas had similar staining characteristics. BerEP4 was focally positive (range 10%-20%) in only 3/39 (7.7%) tricholemmomas compared with widespread positivity in BCC (90.8%, 139 of 151 cases with ≥50% tumor area stained). CD34 was expressed, usually focally (median 20%, range 10%-90%), in 52/53 (98.1%) tricholemmomas and was negative in all 21 BCCs stained. EMA staining lacked sensitivity or specificity in differentiating tricholemmoma from BCC. Five or more Merkel cells were found in 7/17 (40.1%) tricholemmomas and 1/23 (4.3%) nodular BCCs studied. In summary, immunohistochemistry is helpful in distinction between tricholemmoma, including difficult basaloid examples (BerEP4 negative or focal, CD34 positive) compared with BCC (BerEP4 widespread in most cases, CD34 negative). The presence of 5 or more Merkel cells is a relatively specific but not a particularly sensitive discriminator.

Androgenic alopecia, premature graying, and hair thinning as independent predictors of coronary artery disease in young Asian males

We herewith aimed to explore the association of premature graying, androgenic alopecia (AGA), and hair thinning with coronary artery disease (CAD) in young (≤40 years) male individuals from Western India.

Patients and methods

In this prospective, case-control study, 1380 male individuals from a super speciality cardiac care center were enrolled, of which 468 were established cases of CAD and 912 were age-matched healthy male individuals not having history of any major illness including CAD. Details of demographics, cardiovascular risk factors, and cutaneous markers were collected for both the groups.

Results

Prevalence of hypertension (30.3 vs. 13.6%), obesity (28.8 vs. 12.2%), hair thinning (36.3 vs. 14.6%), premature graying (49.6 vs. 29.9%), AGA (49.1 vs. 27.4%), and lipid abnormalities (total cholesterol - 16.7 vs. 8.8%; low-density lipoprotein - 7.3 vs. 2.2%; and high-density lipoprotein - 92.5 vs. 88.7%) were higher in cases as compared with control. Multiple logistic regression analysis showed that AGA [5.619, 95% confidence interval (CI): 4.025-7.845, P<0.0001] is the strongest predictor of CAD among young Asian male individuals, closely followed by premature graying (5.267, 95% CI: 3.716-7.466, P<0.0001), obesity (4.133, 95% CI: 2.839-6.018, P<0.0001), and hair thinning (3.36, 95% CI: 2.452-4.621, P<0.0001). SYNTAX score, left ventricle ejection fraction, and degree of disease severity were also found to be independent associates of premature graying and AGA.

Conclusion

Our findings support the hypothesis that cutaneous markers are independently associated with underlying CAD irrespective of other classical cardiovascular risk factors. This, in combination with classical markers, could be effectively used for early identification and risk stratification of young patients with occult or established CAD.

Premature Graying of Hair: An Independent Risk Marker for Coronary Artery Disease in Smokers - A Retrospective Case Control Study

BACKGROUND

Premature graying of hair as a risk marker among young smokers has a potential of identifying coronary artery disease (CAD) at a very early stage. There is absence of literature that assesses premature graying of hair as an independent marker of CAD in smokers.

MATERIAL AND METHODS

The present single-centre case control study enrolled a total of 62 consecutive chronic smokers (≤ 45 years) (Group I) and 60 consecutive young CAD patients (≤45 years) who were chronic smokers (Group II). Another group comprising of 114 patients (≤45 years) having no smoking history and no cardiac ailments either (Group III) was enrolled as control population. All subjects were males. A detailed history and clinical examination regarding conventional coronary risk factors and carotid intima media thickness was done in both groups.

RESULTS

The carotid intima media thickness, dyslipidemia and blood pressure were significantly higher in group I and II as compared to group III. When the groups were compared for graying of hair, it was found that the group II (i.e., smokers and CAD) had maximum prevalence of graying which was significantly higher than the control as well as smoker groups. The presence of premature graying of hair was associated with 3.24 times the risk of CAD on multiple logistic regression analysis.

CONCLUSION

The presence of premature graying of hair was associated with an increased risk of CAD in young smokers. Premature graying of hair can be used as preliminary evidence by clinicians for classifying patients at risk for premature CAD especially in smokers.

Human epithelial hair follicle stem cells and their progeny: current state of knowledge, the widening gap in translational research and future challenges

Epithelial hair follicle stem cells (eHFSCs) are required to generate, maintain and renew the continuously cycling hair follicle (HF), supply cells that produce the keratinized hair shaft and aid in the reepithelialization of injured skin. Therefore, their study is biologically and clinically important, from alopecia to carcinogenesis and regenerative medicine. However, human eHFSCs remain ill defined compared to their murine counterparts, and it is unclear which murine eHFSC markers really apply to the human HF. We address this by reviewing current concepts on human eHFSC biology, their immediate progeny and their molecular markers, focusing on Keratin 15 and 19, CD200, CD34, PHLDA1, and EpCAM/Ber-EP4. After delineating how human eHFSCs may be selectively targeted experimentally, we close by defining as yet unmet key challenges in human eHFSC research. The ultimate goal is to transfer emerging concepts from murine epithelial stem cell biology to human HF physiology and pathology.

The changes in the expression levels of follicular markers in keratoacanthoma depend on the stage: keratoacanthoma is a follicular neoplasm exhibiting infundibular/isthmic differentiation without expression of CK15

BACKGROUND

Although the precise etiology of keratoacanthoma (KA) is unknown, KA is generally assumed to differentiate toward hair follicles based on previous studies of experimental carcinogenesis.

METHODS

We performed a comprehensive immunohistochemical study of various follicular markers in all stages of KA. A total of 67 tumors, including 16 early or proliferative stage lesions, 43 well-developed stage lesions, five regressing stage lesions and three regressed stage lesions, were subjected to the analysis.

RESULTS

CK15 (clone C8/144B), CK19 and CD34 were not expressed at any stage. CK1, CK10, CK16, CK17, CK15 (clone LHK15) and calretinin showed dynamic changes in their expression in KA depending on the stage.

CONCLUSIONS

KA is a follicular neoplasm with infundibular/isthmic (upper segmental region of hair follicles) differentiation. It is considered that early or proliferative stage tumors show keratin-filled invaginations with infundibular differentiation and gradual isthmic differentiation. Well-developed examples of KA generally show isthmic differentiation in the whole lesions. The regressed stage KAs lose the features of this type of follicular differentiation and show epidermal characteristics. No expression of CK15 (clone C8/144B) was observed in KAs, although this finding is insufficient to completely rule out the correlation between the regression of KA and the hair follicle cycle.

The concept of the onychodermis (specialized nail mesenchyme): an embryological assessment and a comparative analysis with the hair follicle

BACKGROUND

Recently, an intriguing concept was introduced into the literature that defines the area underlying the nail bed as a specific mesenchymal substructure unique to the nail organ. It has been termed onychodermis. The onychodermis expresses CD10 with remarkable specificity. Herein, we compare adult and fetal human hair follicles with fetal nail organs in an attempt to draw analogies for the mesenchyme associated with both adnexal structures.

METHODS

We examined immunohistochemically samples from adult and fetal hair follicles for the expression of CD10, CD34 and the mesenchymal stem cell marker nestin and compared the antigen profile with that of the fetal nail organ.

RESULTS

The CD10-positive/CD34-negative onychodermis is prominently visible at the end of the second trimester. A corresponding follicular structure was not identified, either in the adult or in the developing hair follicle. Nestin staining does not define the onychodermis.

CONCLUSIONS

The concept of the onychodermis is equally valid in the developing nail organ where it is also defined by its expression for CD10. Its function may be related to the anchorage of the overlying nail bed but may also involve a more dynamic role in the induction of hard keratins in the latter, contributing to the formation of the nail plate.

Tricholemmoma and clear cell squamous cell carcinoma (associated with Bowen's disease): immunohistochemical profile in comparison to normal hair follicles

There have been only a few reported comparative immunohistochemical studies of normal hair follicles and tricholemmomas. Clear cell squamous cell carcinomas (SCCs), which are derived from Bowen's disease, histopathologically mimic or are difficult to distinguish from tricholemmal carcinoma. The purpose of and methods used in the present study are as follows: (1) evaluation of whether the immunohistochemical profile (cytokeratin (CK)1, CK10, CK17, CD34, and D2-40) in normal hair follicles is retained in tricholemmomas (11 lesions); and (2) a study of the immunohistochemical profile of in situ or superficially invasive clear cell SCCs (associated with Bowen's disease) (10 lesions) to investigate the presence or absence of tricholemmal differentiation markers in these lesions. The present study demonstrated that (1) the immunohistochemical profile of the normal outer root sheath cells was generally retained in tricholemmomas; (2) in contrast to the D2-40 expression in tricholemmomas (only a peripheral pattern, which is similar to that in the normal outer root sheath), the CD34 expression in tricholemmomas represented in a diffuse pattern, a peripheral pattern, and a combined diffuse and peripheral pattern; (3) tricholemmomas are benign neoplasms with outer root sheath (below the isthmus) differentiation, which characteristically show upregulation of CD34 expression with some functionally similar conditions to the terminal hair follicles in the anagen phase; and (4) there is no clear immunohistochemical evidence of tricholemmal differentiation in clear cell SCC (associated with Bowen's disease).