Reassessment of diagnostic criteria in cutaneous lymphocytic infiltrates.
BACKGROUND
Non-specific lymphocytic infiltrates of the skin pose difficulties in daily practice in pathology. There is still a lack of pathognomonic signs for the differential diagnosis between benign and malignant lymphocytic infiltrates.


OBJECTIVE
To evaluate the morphological and immunohistochemical profile of lymphocytic infiltrations of the skin according to clinical outcome.


METHODS
Retrospective; histopathological and immunohistochemical analysis.


METHODS
Referral center, university hospital.


METHODS
28 cases of lymphocytic infiltrates of difficult differential diagnosis selected from the records.


METHODS
Eighteen histological variables and the immunophenotypic profile were assessed using the CD4, CD8, CD3, CD20 and CD30 lymphoid markers and compared to subsequent follow-up.


RESULTS
The most common diagnoses were: initial mycosis fungoides (eight cases) and drug reactions (five cases). Single morphological variables did not discriminate between benign and malignant infiltrates except for the presence of Pautrier-Darier's microabscesses, which were found only in mycosis fungoides (p = 0.015). Patterns of superficial and deep infiltration (p = 0.037) and also the presence of eosinophils (p = 0.0207) were more frequently found in benign lymphocytic infiltrates. Immunohistochemical profile of T-cell subsets showed overlap between benign and malignant infiltrates with a predominance of CD4-positive (helper) lymphocytes in the majority of cases.


CONCLUSIONS
A combination of clinical and histological features remains the most reliable approach for establishing a definite diagnosis in cases of lymphoid skin infiltrates.
Cotta
Ana Cristina
AC
Department of Pathology, School of Medical Sciences, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil.
Cintra
Maria Letícia
ML
de Souza
Elemir Macedo
EM
Magna
Luis Alberto
LA
Vassallo
José
J
D015703:Antigens, CD / Q000032:analysis; D016516:CD4-CD8 Ratio; D016009:Chi-Square Distribution; D003937:Diagnosis, Differential; D005500:Follow-Up Studies; D006801:Humans; D009182:Mycosis Fungoides / Q000473:pathology*; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000473:pathology*; D018709:Statistics, Nonparametric
D015703:Antigens, CD