title: Evaluation of classic architectural criteria in non-mycosis fungoides cutaneous lymphomas.
abstract: Ninety-seven cases of non-mycosis fungoides (non-MF) cutaneous lymphoma were evaluated employing published criteria for the categorization of B- and T-cell cutaneous malignancies. Included in the study were 77 primary and secondary cutaneous B-cell lymphomas, in which the diagnosis was supported by immunohistochemical studies identifying lineage. These cases were randomized with 20 cases of non-MF and T-cell lymphoma. Hematoxylin and eosin (H & E)-stained slides from each case were reviewed by at least two dermatopathologists, who were unaware of the previous diagnoses, and a judgment regarding histologic pattern was rendered. The histologic criteria employed emphasized architectural features. For B-cell patterns, these included the presence of dense perivascular, periappendageal and/or nodular collections of lymphocytes, centering in the deep dermis, and separation from the epidermis by a grenz zone. Employed criteria for cutaneous T-cell pattern included location restricted primarily to the upper dermis, interstitial pattern, the presence of epidermotropism, and the lack of a grenz zone. Three B-cell lymphomas were judged to have indeterminate patterns. Four of 74 (5.4%) of the remaining B-cell lymphomas were incorrectly categorized as T-cell lymphomas by architectural criteria. The most striking findings included epidermotropism in rare B-cell lymphomas. Three of the four miscategorized cases were large-cell lymphomas. A preference for B-cell pattern was also confirmed in non-MF T-cell lymphomas. We conclude that most B-cell lymphomas in the skin demonstrate a recognizable B-cell pattern, but rarely a pattern more reminiscent of T-cell lymphoma may be seen. This may occur more often with B-large-cell lymphomas. In addition, this study supports previous work indicating that many non-MF T-cell lymphomas show prominent architectural features typically ascribed to B-cell lymphomas. In summary, our findings support the impression that the vast majority of non-MF lymphomas show a B-cell pattern regardless of their lineage. As such, caution is indicated with regard to pattern interpretation.
authors.affiliation: Department of Pathology, Yale University Medical Center, New Haven, Connecticut 06520-8059, USA.
authors.forename: E J
authors.initials: EJ
authors.lastname: Glusac
authors.forename: S E
authors.initials: SE
authors.lastname: Kindel
authors.forename: R A
authors.initials: RA
authors.lastname: Soslow
authors.forename: B R
authors.initials: BR
authors.lastname: Smoller
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D019070:Cell Lineage; D003937:Diagnosis, Differential; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016393:Lymphoma, B-Cell / Q000145:classification / Q000473:pathology*; D016410:Lymphoma, T-Cell, Cutaneous / Q000145:classification / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009182:Mycosis Fungoides / Q000473:pathology*; D012867:Skin / Q000166:cytology / Q000473:pathology; D012878:Skin Neoplasms / Q000145:classification / Q000473:pathology*