Sarcoidosis Coexisting With Distinct Forms of Alopecia on the Scalp: A Case Series.

ABSTRACT: Sarcoidosis is an idiopathic multisystem inflammatory disease that can affect virtually any part of the body. Often, it can initially present solely in the skin. Histologically, it is characterized by noncaseating, 'naked' granulomas in the dermis and subcutaneous tissue. Clinically, sarcoidosis is often referred to as a 'mimicker' of many other pathologic processes because of its wide array of presentations. Occasionally, sarcoidosis can present in the scalp as both a scarring and nonscarring alopecia. There are countless reports of sarcoidosis mimicking various other alopecias including acne keloidalis nuchae, discoid lupus erythematosus, frontal fibrosing alopecia, lichen planopilaris, and alopecia areata totalis. In this case series, we present 2 novel cases of sarcoidosis not just clinically mimicking other forms of alopecia but occurring in conjunction with a separate and histologically distinct primary alopecia.

Interpretive disparity among pathologists in breast sentinel lymph node evaluation.

BACKGROUND: Immunohistochemical staining on breast sentinel lymph nodes (SLN) is controversial. METHODS: Twenty-five SLN cases were reviewed by 10 pathologists (three academic, seven private) including 5 negative by both hematoxylin and eosin (H&E) and immunohistochemistry, 11 micrometastases (<2 mm) negative by H&E but positive by immunohistochemistry, and 8 micrometastases and 1 macrometastasis (>2 mm) positive for both H&E and immunohistochemistry. Answers included "positive," "negative," and "indeterminate" for each slide. RESULTS: The mean number of incorrect responses was 6.6 for immunohistochemistry and 5 for H&E. Twelve percent of cases were correct by all 10 pathologists; 80% of positive IHC cases had at least one pathologist score it incorrectly. As tumor cells decrease in number, incorrect responses increase. When tumor cells numbered less than 10, more than 30% of pathologists answered incorrectly. CONCLUSIONS: As tumor cells decrease in number pathologists' ability to recognize them decreases. We propose adding "indeterminate" to "positive" and "negative" when tumor cells number less than 10.