CASE REPORT: A 34-year-old woman with intractable epigastric pain was referred to have repeated endoscopy with biopsy. She was found to multiple gastric erosions and nodules that were diagnosed as inflammatory lesions both endoscopically and histologically. Meanwhile, she developed an acute onset of severe back pain associated with a pathologic compression fracture in the T3 thoracic vertebral body. Imaging studies disclosed a disseminated systemic disease involving abdominopelvic lymph nodes and cervical and thoracic vertebral bodies. The needle biopsy of the pelvic lymph node disclosed diffuse proliferation of monomorphic small round cells that were diffusely positive for CD30 and ALK. A diagnosis of ALK+ ALCL with a monomorphic SC pattern was rendered.
DISCUSSION: A retrospective review of the gastric biopsies with the aid of immunohistochemistry enabled us to recognise the presence of lymphomatous infiltrates with a mixed LH and SC pattern in every piece of gastric biopsies that were repeatedly misdiagnosed as inflammatory lesions. This case illustrates a significant diagnostic pitfall of the LH- and SC-patterns in ALK+ ALCL, in which the tumour cells featuring lymphoid, plasmacytoid or histiocytoid appearance can be masqueraded as inflammatory cells.
METHODS: A synthetic human scFv phage antibody library was used to select phage-displayed antibody fragments that recognized CD1b-Ac2SGL using CD1b-transfected THP-1 cells loaded with Ac2SGL.
RESULTS: One clone, D11-a single, light-variable domain (kappa) antibody (dAbκ11)-showed high relative binding to the Ac2SGL-CD1b complex.
CONCLUSION: A ligand recognizing the Ac2SGL-CD1b complex was obtained, which is a potential candidate to be further tested for diagnostic and therapeutic applications.