Blue Blob-Like Bodies Mimicking Malignancy

Abstract

Background: Incidental morphologic findings in lymph node tissue may represent a diagnostic challenge in surgical pathology. We have characterized, for the first time to our knowledge, dense globular structures that most likely represent degenerated lymphoid cells found in a Mascagni-Lund's lymph node, and resemble Blue Blobs (Bbs) described in vaginal Papanicolaou-stained smears, or Hematoxylin Bodies (Hbs) commonly seen in patients diagnosed with Systemic Lupus Erythematosus (SLE), respectively. These Blue Blob-Like Bodies (Bbbs) are not associated with SLE, and immunohistochemistry may be necessary to rule out malignancy or viral infection.Objective: To characterize Blue Blob-Like Bodies (Bbbs) in a Mascagni-Lund's lymph node from a cholecystectomy specimen performed for acute cholecystitis. Materials and Method:A paraffin-embedded cholecystectomy specimen that included a Mascagni-Lund's lymph node was evaluated by routine microscopy in a busy surgical pathology service. Special stains, immunohistochemistry, and electron microscopy were performed to characterize the unusual structures observed.Results: Many scattered, round-to-oval, dense globular basophilic novel structures with smooth borders were identified and named Blue Blob-Like Bodies (Bbbs). Conclusion:Bbbs mimic malignant (primary or metastatic) or virally infected cells in lymph node tissue. However, they most likely represent degenerated lymphoid cells resulting from reactive lymphadenopathy secondary to acute cholecystitis.Pathologists need to recognize Bbbs and properly distinguish them from other pathological structures, in order to avoid misdiagnosis.