Viktoryia Kazlouskaya

Phosphohistone‐H3 and Ki‐67 immunostaining in cutaneous pilar leiomyoma and leiomyosarcoma (atypical intradermal smooth muscle neoplasm)

The mitotic index is important in the assessment of tumors such as leiomyoma (LM) and leiomyosarcoma (LMS), which may exhibit a range of cytological atypia. The mitotic marker phosphohistone‐H3 (PHH3) was shown to improve interobserver and intraobserver variability in many tumors.

The utility of elastic Verhoeff‐Van Gieson staining in dermatopathology

Elastic fibers are important components of the skin and are responsible for skin elasticity. Genetic defects are well‐known in numerous hereditary elastic tissue disorders and skin biopsies are often the first step in the evaluation of those disorders. Verhoeff‐Van Gieson elastic staining is a simple method that is used for visualizing elastic fibers. With the development of modern immunohistochemical methods, the value of routine histochemical staining is sometimes underestimated. Histochemical stains are less expensive, easy to perform and help to resolve numerous diagnostic quandaries in dermatopathology. This article focuses on the value of elastic tissue staining in dermatopathology, with a focus on primary elastic tissue disorders, alopecia, inflammatory skin disorders and neoplastic proliferations.

Annular lichenoid dermatitis of youth: a separate entity or on the spectrum of mycosis fungoides? Case report and review of the literature

Annular lichenoid dermatitis (ALDY) is a rare dermatosis that is most often seen in children and young adults and is characterized by annular patches with raised borders, most frequently on the trunk and the groin. A distinct lichenoid tissue reaction involving the base of the rete, resulting in squared‐off rete ridges, helps to differentiate this from other lichenoid dermatoses and mycosis fungoides (MF). Herein, we report an additional case of this condition in a 7‐year‐boy, whose biopsy exhibited the typical quadrangular rete alteration and also contained distinct aggregates of CD8+ lymphocytes, Langerhans cells and colloid bodies within the involved rete. A literature review with emphasis on the clinical and histopathological differential diagnosis reveals additional clinical features of ALDY to potentially help differentiate this entity from annular presentations of mycosis fungoides.

Elastic staining versus fluorescent and polarized microscopy in the diagnosis of alopecia

BACKGROUND Recently, polarized microscopy was reported as helpful in the evaluation of alopecia biopsy specimens. OBJECTIVE We sought to determine the usefulness of polarized microscopy relative to elastic tissue staining and fluorescent microscopy. METHODS Histologic sections from 60 alopecia specimens were evaluated to determine the pattern of elastic tissue in elastic van Gieson-stained sections. Comparable hematoxylin-eosin sections were examined under a fluorescent microscope to determine the elastic tissue pattern and examined under polarized microscopy to determine the pattern of birefringence. RESULTS Elastic van Gieson staining demonstrated high sensitivity (1.0) and high specificity (1.0) for the identification of nonscarring alopecia. In 54 of 60 cases, fluorescent microscopy demonstrated an identical pattern of elastic tissue. High background eosin fluorescence made it impossible to interpret the elastic tissue pattern in the remaining 6 specimens. Strong birefringence in dermal collagen sparing fibrous tracts had high specificity (1.0) but lower sensitivity (0.59). Strong collagen birefringence within the dermis and broad fibrous tracts were present in all 6 cases of central centrifugal cicatricial alopecia. LIMITATIONS Elimination of the 6 uninterpretable specimens with high background fluorescence from our calculations may be a source of bias, as these cases could potentially all have been either negative or positive. CONCLUSION Elastic tissue staining is the most reliable means to determine the pattern of scarring in alopecia biopsy specimens. In most cases, fluorescent microscopy of hematoxylin-eosin sections shows an identical pattern. Although a pattern of collagen birefringence on polarized microscopy distinctly sparing fibrous tract is specific for nonscarring alopecia, not all cases of nonscarring alopecia demonstrate this pattern. Strong collagen birefringence within both the dermis and fibrous tracts suggests a diagnosis of central centrifugal cicatricial alopecia.

Dermal changes in superficial basal cell carcinoma, melanoma in situ and actinic keratosis and their implications

Basal cell carcinoma (BCC) has a characteristic stroma, but less is known about the dermal characteristics associated with melanoma in situ (MIS) and actinic keratosis (AK).

Expression of p16 protein in lesional and perilesional condyloma acuminata and bowenoid papulosis: Clinical significance and diagnostic implications

BACKGROUND The histopathological and clinical overlapping features between condyloma acuminata and bowenoid papulosis can present a diagnostic challenge and we sought to determine if immunochemistry can be helpful in this setting. OBJECTIVE In this study, we evaluate the specificity and sensitivity of p16 immunohistochemistry in condyloma and bowenoid papulosis lesions compared with uninvolved perilesional skin and discuss the possible clinical implications. METHODS A total of 36 skin biopsy specimens (24 samples of condyloma and 12 samples of bowenoid papulosis with adjacent uninvolved perilesional skin) were stained with an antibody to p16 protein. RESULTS In all, 75% of condyloma lesions showed sporadic and focal positive staining for p16 protein. All cases of bowenoid papulosis showed diffuse positive staining with p16 protein. Normal-appearing adjacent skin was negative in all cases. LIMITATIONS Studies with a larger number of cases are needed to confirm our data. CONCLUSION This immunostain has high sensitivity and specificity for the detection of bowenoid papulosis. Although p16 is expressed in both conditions, the staining pattern in bowenoid papulosis is strongly and diffusely positive involving the full thickness of the epidermis compared with the mostly focal or sporadic pattern observed in condyloma.

Solitary epidermolytic acanthoma

Solitary epidermolytic acanthoma is thought to be an uncommon lesion. It can present as a solitary, localized or disseminated process that is unrelated to the genetic form of icthyosis.

Perforating elastic fibers ('elastic fiber trapping') in the differentiation of keratoacanthoma, conventional squamous cell carcinoma and pseudocarcinomatous epithelial hyperplasia.

Keratoacanthoma (KA), an epithelial neoplasm occurring in sun‐exposed skin of the elderly, is considered a well‐differentiated form of conventional squamous cell carcinoma (SCC) that often follows a course of spontaneous regression. Distinguishing KA from conventional SCC or pseudocarcinomatous epithelial hyperplasia ensures proper diagnosis, treatment and management. For some time, perforating elastic fibers have been utilized in differentiating KA from SCC. This phenomenon may also occur in association with scars and hypertrophic lupus erythematosus (LE). To assess the diagnostic utility of perforating elastic fibers, we compared their incidence in KA, SCC, scars with overlying pseudocarcinomatous hyperplasia, hypertrophic LE, hypertrophic lichen planus (LP) and lichen simplex chronicus (LSC). A retrospective case search identified 359 lesions and the presence of perforating elastic fibers was evaluated using routinely stained sections. This phenomenon was documented in all studied groups except hypertrophic LP. The incidence was found to be 71% in KA, 37% in SCC, and was lowest in inflammatory conditions with associated pseudocarcinomatous hyperplasia (hypertrophic LP 0%, hypertrophic LE 5.9% and LSC 28.2%). The observed frequency in pseudocarcinomatous hyperplasia overlying scars (57.8%) vs. KA (71%) was not statistically different. Although elastic fiber trapping has potential value as a diagnostic criterion for KA, dermatopathologists should consider its limitations. Its diagnostic utility was greatest in distinguishing KA from hypertrophic LE and hypertrophic LP. Conversely, elastic trapping is not helpful differentiating pseudocarcinomatous hyperplasia from recurrent/persistent KA following surgery.

Pustular secondary syphilis: report of three cases and review of the literature.

Pustular syphilis is an extremely rare manifestation of secondary syphilis. Failure to recognize the disease can have devastating consequences.

Diagnostic cellular abnormalities in neoplastic and non‐neoplastic lesions of the epidermis: a morphological and statistical study

Distinguishing cellular abnormalities in reactive and malignant lesions is challenging. We compared the incidence and severity of cytological abnormalities in malignant/premalignant and benign epidermal lesions.