Amira Elbendary

BACKGROUND: Interpretation of Clark's nevi has generated debate over the years; although criteria have been proposed for grading morphological features of melanocytes, there is still confusion and variability in the assessment of these lesions.

METHODS: This is a retrospective observational study conducted on 100 Clark's nevi and 84 melanomas. A single expert dermatopathologist evaluated all blinded and randomized photomicrographs of both the Clark's nevi and melanomas for the presence of 14 cytologic features. Subsequently, a multivariate model was used to obtain sensitivity and specificity.

RESULTS: Clark's nevi showed a significantly higher frequency of absent-or-inconspicuous nucleoli over melanoma, whereas mitotic figures, pleomorphism, notching, multiple nucleoli, peppered moth nuclear pattern, flattened adjacent nuclei, prominent nucleoli and vesicular nucleus with rounded nucleoli were found significantly higher in frequency in melanomas.

CONCLUSION: Our data suggest that nuclear alterations are of value in the differentiation of atypical nevi from melanoma.

BACKGROUND: Paget disease, Bowen disease, and malignant melanoma in situ are intraepidermal neoplasms, characterized by the presence of pagetoid scatter of atypical cells in the epidermis. This study reviewed the frequency of select histologic criteria to validate their usefulness in the histologic distinction between these entities.

METHODS: One hundred forty-four specimens with the diagnosis of Bowen disease, 144 specimens with Paget disease (mammary and extramammary), and 144 specimens with malignant melanoma in situ were examined microscopically to define frequencies of select histologic criteria present in each disease.

RESULTS: Comparison between mammary Paget and extramammary Paget disease showed no significant differences in the features studied. Crushing of basal keratinocytes, presence of atypical cells in the corneum, and presence of large cells with amphophilic cytoplasm were significantly noted in Paget disease. Transition between the atypical clear cells and surrounding keratinocytes was absent in all cases of melanoma in situ and in 87 (60.4%) cases of Paget disease, but it was significantly associated with Bowen disease (98.6%). Dyskeratotic cells were significantly associated with Bowen disease cases.

CONCLUSION: Our study demonstrated a practical histologic approach to differentiate between intraepidermal pagetoid neoplasms. Careful histologic study of the proposed criteria may reduce reliance on immunohistochemical stains.

BACKGROUND: Precancerous high-grade squamous intraepithelial lesion (HSIL), the current consensus terminology for anogenital squamous cell carcinoma in situ (SCCIS), often presents with distinctive histopathologic findings that may be a function of anatomic site or associated human papillomavirus infection.

METHODS: Fifty-six specimens of anogenital HSIL were compared with an equal number of specimens of SCCIS from non-anogenital sites in regard to the presence of parakeratosis, flag sign in the stratum corneum, compact stratum corneum, hypergranulosis, koilocytes, small blue cells, clonal populations of keratinocytes, pagetoid scatter of atypical keratinocytes, clear cell change, glassy red cytoplasm, pigmentation, nuclear/cytoplasmic(N/C) ratio >2/1, nuclear hyperchromasia, pleomorphic nuclei, mitotic figures, abnormal mitotic figures, dyskeratotic keratinocytes, involvement of skin appendages, acantholysis and amyloid deposition.

RESULTS: Hypergranulosis, koilocytes, small blue cells, pigmentation, nuclear hyperchromasia, dyskeratotic keratinocytes and amyloid deposition were more frequently noted in anogenital HSIL. Parakeratosis, clear cell change, pleomorphic nuclei, skin appendages involvement and acantholysis were strongly associated with non-anogenital location. There was no significant difference in the incidence of the remaining features.

CONCLUSION: The strongest predicators of an anogenital location included hypergranulosis, koilocytes, small blue cells and nuclear hyperchromasia. Pigmentation and amyloid deposition were also strongly associated with an anogenital location.

BACKGROUND: The histopathologic features of tinea vary widely and its diagnosis could be easily missed if the index of suspicion is not high. We aimed in this study to detect histopathologic features that could be a clue for diagnosis

METHODS: We retrospectively reviewed 103 cases of tinea, confirmed by Periodic acid-Schiff (PAS) staining. For each case, gender, biopsy site, and pre-biopsy suspicion were recorded. The presence or absence of 17 microscopic features was noted.

RESULTS: Concordance between pre-biopsy and histopathologic diagnosis was noted in 57.28% of cases, suggesting that the diagnosis is often not suspected clinically. Among the histopathologic features studied, a compact stratum corneum (either uniform or forming a layer beneath a basket weave stratum corneum), parakeratosis, mild spongiosis and neutrophils in the stratum corneum and within the blood vessels were the most frequent features noted.

CONCLUSION: This study suggests histopathologic clues that should prompt the pathologist to order a PAS stain, especially when diagnosis is not suspected clinically.

BACKGROUND: Many authors have described cytologic features in a variety of melanocytic lesions but, to our knowledge, a statistical analysis of sensitivity, specificity, and overall accuracy of these features alone or in combination has not been performed.

OBJECTIVE: We sought to determine the diagnostic value of nuclear and cytoplasmic characteristics in the diagnosis of melanocytic lesions via multivariate statistical analysis.

METHODS: This is a retrospective observational study conducted on 300 melanocytic lesions. We evaluated a series of distinctive features; subsequently a multivariate model was used to determine sensitivity and specificity.

RESULTS: Major features that favor a diagnosis of melanoma include: pleomorphism with enlarged nuclei, mitotic figures, notching/corrugation of the nuclear envelope, and peppered moth nucleus. Features with intermediate value include: solid hyperchromasia, vesicular nucleus with single round nucleolus, and nuclear/cytoplasmic ratio greater than 4:1.

LIMITATIONS: Limitations of this study include its retrospective nature, and the reliance on the original diagnostic classification of each neoplasm.

CONCLUSION: Our data suggest that some nuclear alterations have greater value in the diagnosis of benign and malignant melanocytic lesions.

Hidradenoma papilliferum is a benign cutaneous adnexal neoplasm, commonly occurring in the vulva and perianal region of adult women. It has characteristic histopathological features composed of anastomosing and branching tubules, lined by columnar cells, and a basal layer of myoepithelial cells. A 39-year-old woman was evaluated for 2 asymptomatic labial masses. The histopathological examination revealed a Bartholin's cyst and a hidradenoma papilliferum. The latter contains a distinct area of oncocytic/oxyphilic metaplasia. Immunohistochemical stains revealed positive staining for gross cystic disease fluid protein (GCDFP)-15 and androgen receptor. GATA-3, a protein expressed in sweat glands, highlights a similar positive staining pattern with weaker staining in areas of oncocytic metaplasia. P63 highlighted the myoepithelial differentiation. In situ hybridization for Human Papilloma Virus 6, 11, 16, and 18 was negative. P53 was negative and Ki-67 was low, confirming its benign nature. Oncocytes are enlarged epithelial cells with voluminous eosinophilic granular cytoplasm resulting from staining of nonribosomal cytoplasmic components. Few reports documented it in hidradenoma papilliferum. Our case demonstrated a florid distinct appearance of this metaplasia. The immunoprofiles of this oncocytic metaplasia such as p53 negativity and positivity for androgen receptor and GCDFP-15 demonstrates similarity to apocrine metaplasia in the breast. The authors' case demonstrates the benign nature of oncocytic metaplasia and supports the common origin of oncocytic cells and columnar cells in hidradenoma papilliferum.