Reassessment of diagnostic criteria in cutaneous lymphocytic infiltrates

• Main Author: Cotta, Ana Cristina
• Publication Date: 2004
• Other Authors: Cintra, Maria Letícia, Souza, Elemir Macedo de, Magna, Luis Alberto, Vassallo, José
• Format: Article
• Language: eng
• Source: São Paulo medical journal (Online)
• Download full: https://periodicosapm.emnuvens.com.br/spmj/article/view/2514
• topic: Linfoma de Células T Cutâneo; Pseudolinfoma; Micose fungóide; Imunohistoquímica; Diagnóstico diferencial; Cutaneous T-cell lymphoma; Pseudolymphoma; Mycosis fungoides; Immunohistochemistry; Differential diagnosis

CONTEXT: 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. TYPE OF STUDY: Retrospective; histopathological and immunohistochemical analysis. SETTING: Referral center, university hospital. SAMPLE: 28 cases of lymphocytic infiltrates of difficult differential diagnosis selected from the records. MAIN MEASUREMENTS: 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.