[Histological and clinical characteristics of cases of immunoglobulin G4-related disease in a tertiary hospital, in Cali, Colombia]. / Caracterización histológica y clínica de pacientes con enfermedad relacionada con inmunoglobulina G4 en un centro de alta complejidad en Cali, Colombia.

INTRODUCTION: Immunoglobulin G4 (IgG4)-related disease has been described in the last decade. It is a fibro-inflammatory condition capable of affecting almost every organ and diagnosis requires both clinical and paraclinical confirmation. We present the largest study to date in Colombia. OBJECTIVE: To describe the clinical and histopathological characteristics of patients diagnosed with IgG4-related disease at the Fundación Valle del Lili. METHODS: Observational-descriptive retrospective study. The clinical and pathological records of patients diagnosed with IgG4-related disease at the Fundación Valle del Lili were reviewed and a descriptive statistical analysis made. RESULTS: From 2013-2016, 16 patients were diagnosed. Median age was 44 years (RIC 30-58) and 10 (62.5%) were women. The most common clinical presentation was a combination of a tumefactive mass, constitutional symptoms and site-related symptoms (43.8%) (n=7). No preference for any organ was seen. Histopathology revealed all cases had dense lymphoplasmacytic infiltrate and storiform-type fibrosis; 75% also had obliterative phlebitis. In all cases≥10 cells/HPF of IgG4+ were found and 81% had a ratio of IgG4+/IgG+>50%. CONCLUSION: IgG4-related disease appears to be underdiagnosed, probably due to its broad clinical spectrum as well as a low index of awareness among clinicians. We recommend that, when dense lymphoplasmacytic infiltrates, storiform-type fibrosis or obliterative phlebitis are found, immunohistochemistry for IgG and IgG4should be requested. Positive results then must be correlated with complementary studies to confirm the disease.