Sandy Lucero Granados-López1, Sonia Tousaint-Caire2, Clemente Moreno-Collado3, Mauricio Brindis-Zabaleta4, Carlos Ortiz-Hidalgo5. 1. Departamento de Patología Quirúrgica y Molecular, Centro Médico ABC, México, D.F. 2. Departamento de Dermatología, Hospital General Dr. Manuel Gea González. SS, México, D.F. 3. Departamento de Dermatología, Centro Médico ABC, México, D.F. 4. Laboratorio de Anatomía Patológica. Hospital de Especialidades ISSTEH. Tuxtla Gutiérrez, Chiapas, México, D.F. 5. Departamento de Patología Quirúrgica y Molecular, Centro Médico ABC, México, D.F.; Departamento de Biología Celular y Tisular, Universidad Panamericana, México, D.F.
Abstract
INTRODUCTION: Pseudolymphomatous folliculitis (PLF) is a rare benign cutaneous lymphoid hyperplasia that most commonly occurs in the facial region as a dome-shaped or flat elevated nodule. MATERIALS AND METHODS: We studied the clinicopathologic and immunohistochemical characteristics of 19 cases of PLF. RESULTS: The patients comprised 11 females and eight men (mean age 44.9; age range 9-77 years). All cases were solitary except one case with multiple lesions. The lesions were located in the facial region except one that was located in the back. Histologically, there was a diffuse or nodular lymphoid infiltrate with hyperplastic and distorted hair follicles and occasionally enlarged eccrine units with a clear nuclear morphology. Immunohistologically, three cases showed predominantly B-cells, eight cases predominantly B-cells with numerous T-cells, six cases predominantly T-cells with numerous B-cells, and two cases predominantly T-cells. All lesions showed increased numbers of perifollicular dendritic cells expressing anti-S-100 protein and CD1a. DISCUSSION: PLF is a rare, benign, cutaneous lymphoid hyperplasia that may resemble cutaneous lymphoma. It has characteristic clinical and pathologic features showing abundant periadnexal S-100/CD1a -positive dendritic cells with dilated and activated pilosebaceous units. The lesion may resolve with complete excision or present spontaneous regression.
INTRODUCTION:Pseudolymphomatous folliculitis (PLF) is a rare benign cutaneous lymphoid hyperplasia that most commonly occurs in the facial region as a dome-shaped or flat elevated nodule. MATERIALS AND METHODS: We studied the clinicopathologic and immunohistochemical characteristics of 19 cases of PLF. RESULTS: The patients comprised 11 females and eight men (mean age 44.9; age range 9-77 years). All cases were solitary except one case with multiple lesions. The lesions were located in the facial region except one that was located in the back. Histologically, there was a diffuse or nodular lymphoid infiltrate with hyperplastic and distorted hair follicles and occasionally enlarged eccrine units with a clear nuclear morphology. Immunohistologically, three cases showed predominantly B-cells, eight cases predominantly B-cells with numerous T-cells, six cases predominantly T-cells with numerous B-cells, and two cases predominantly T-cells. All lesions showed increased numbers of perifollicular dendritic cells expressing anti-S-100 protein and CD1a. DISCUSSION: PLF is a rare, benign, cutaneous lymphoid hyperplasia that may resemble cutaneous lymphoma. It has characteristic clinical and pathologic features showing abundant periadnexal S-100/CD1a -positive dendritic cells with dilated and activated pilosebaceous units. The lesion may resolve with complete excision or present spontaneous regression.