Best practices in diagnostic immunohistochemistry: workup of cutaneous lymphoid lesions in the diagnosis of primary cutaneous lymphoma.
BACKGROUND
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.


METHODS
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.
From the Department of Pathology, Beth Israel Deaconess Medical Center, and Harvard Medical School, Boston, Massachusetts (Dr Dewar); the Department of Pathology, University of Michigan, Ann Arbor (Dr Andea); the Department of Pathology and Dermatology, Northwestern University, Chicago, Illinois (Dr Guitart); the Department of Pathology, Stanford University Medical Center, Stanford, California (Dr Arber); and the Department of Hematopathology, Clarient Pathology Services, Inc, Aliso Viejo, California (Dr Weiss).
Rajan
R
Dewar
Aleodor Alexandru
AA
Andea
Joan
J
Guitart
Daniel A
DA
Arber
Lawrence M
LM
Weiss
D006801:Humans; D007150:Immunohistochemistry / Q000379:methods / Q000592:standards; D016393:Lymphoma, B-Cell / Q000175:diagnosis*; D016410:Lymphoma, T-Cell, Cutaneous / Q000175:diagnosis*; D012878:Skin Neoplasms / Q000175:diagnosis*