Abstract
In the spectrum of diffuse large B-cell lymphomas (DLBCL), both T-cell/histiocyte-rich large B-cell lymphoma (TCHRBCL) and most lymphomatoid granulomatosis (LG) cases are characterized by the relative rarity of the neoplastic B-cell population, with respect to the overwhelming non-neoplastic counterpart of T cells or histiocytes. Here we report a case of aggressive B-cell lymphoma with unusual clinicopathological features partially overlapping these two entities. The patient was a previously healthy 55-year-old male, presenting with a computed tomography finding of a pelvic mass, inguinal lymphadenopathies, and pulmonary nodules. Two excisional lymph node biopsies resulted inconclusive for lymphoproliferative disease. Because of a colonic perforation, the patient underwent an urgent laparotomy, which disclosed a large pelvic abscess. The pathological examination of the surgical specimen could not discriminate between a primary aggressive B-cell lymphoproliferative disorder and an abnormal inflammatory hyper-reaction. The patient developed a septic state, not resolving until death, which occurred because of an abdominal hemorrhage. A second perimortem surgical specimen consisting of a nodal mass revealed a diagnosis of an Epstein-Barr virus-negative high-grade large B-cell lymphoma with massive necrosis, angiocentric pattern of growth, and prominent T-cell infiltrate. The unique clinicopathological features did not allow to classify this tumor within any of the recognized WHO entities, potentially representing a new clinicopathological variant of DLBCL in-between TCHRBCL and LG.