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The College of American Pathologists offers these templates to assist pathologists in providing clinically useful and relevant information when reporting results of biomarker testing. The College regards the reporting elements [...]

Context.--Primary cutaneous lymphoma is a common extranodal non-Hodgkin lymphoma. These lesions share common features with their nodal counterparts, but also have differences in morphology, unique clinical presentations, and immunohistochemical features. Objective.--To review the 2008 World Health Organization (WHO) and 2005 consensus WHO-EORTC (European Organisation for Research and Treatment of Cancer) classifications, and address the immunohistochemical findings in the most common primary cutaneous T- and B-cell lymphomas. Since clonality testing is commonly used as an ancillary test in the evaluation of cutaneous lymphoma, a brief section in the use and pitfalls of clonality testing is included. Data Sources.--The WHO and EORTC classification publications and the relevant recent literature were used to compile appropriate and practical guidelines in this review. Conclusions.--The practice of dermatopathology and hematopathology varies widely. Thus, while this review provides an overview and guideline for the workup of lymphoid lesions of the skin, the practitioner should understand the importance of clinical correlation as well as appropriate utility of available resources (such as clonality testing) in arriving at a diagnosis in cutaneous lymphoid lesions. (Arch Pathol Lab Med. 2015; 139:338-350; doi: 10.5858/arpa.2014-0018-CP), The skin is the second most common extranodal site for non-Hodgkin lymphoma after the gastrointestinal tract. Primary cutaneous lymphomas comprise a diverse group of distinct lesions, arising from T cells [...]

Clear cell melanoma is a rare clear cell malignancy. Accurate diagnosis of clear cell melanoma requires integration of immunohistochemical and morphologic findings, with molecular studies to rule out clear cell sarcoma. The differential diagnosis includes melanoma, carcinoma, perivascular epithelioid cell tumor, and epidermotropic clear cell sarcoma. We use a case of a lesion on the helix of an 86-year-old man as an example. Histologic examination revealed an ulcerated clear cell malignant tumor. Tumor cell cytoplasm contained periodic acid-Schiff-positive, diastase-sensitive glycogen. Tumor cells showed positive labeling for S100, HMB-45, and Melan-A, and negative labeling for cytokeratins, p63, and smooth muscle actin. Molecular studies demonstrated BRAF V600E mutation, copy gains at the 6p25 (RREB1) and 11q13 (CCND1) loci, and absence of EWSR1-ATF1 fusion. These findings supported a diagnosis of clear cell melanoma. The rare pure clear cell morphology occurs due to accumulation of intracytoplasmic glycogen. We review the differential diagnosis of clear cell melanoma and describe the utility of immunohistochemical and molecular studies in confirming this diagnosis. (Arch Pathol Lab Med. 2014; 138:1328-1336; doi: 10.5858/arpa.2014-0307-CC), STUDY CASE Clear cell melanoma is a rare clear cell malignancy. Accurate diagnosis of clear cell melanoma requires integration of immunohistochemical and morphologic findings, with molecular studies to rule out [...]

To the Editor.--We read with interest the article by Chaudhry and Zembowicz, (1) entitled 'Adnexal Clear Cell Carcinoma With Comedonecrosis: Clinicopathologic Analysis of 12 Cases,' in which they described a [...]

To the Editor.--We read with great interest the recent article entitled "Synchronous Occurrence of Epithelial and Stromal Tumors in the Stomach," by Maiorana et al,[1] in which the authors report [...]

To the Editor: We report a 66-year-old female seen in consultation for psoriasis not responding to topical therapy. Upon examination, she had well-demarcated erythematous scaly plaques on her elbows, knees [...]