Sepideh Amin1, Alan Ramsay. 1. Department of Eye Pathology, Institute of Ophthalmology, London, UK. s.amin@doctors.org.uk
Abstract
AIMS: Progressive transformation of germinal centres (PTGC) is a reactive process of undetermined aetiology. Although usually seen as nodal disease, it can occur at extra-nodal sites, such as oral cavity, gastrointestinal tract and skin. To determine if PTGC occurs in the orbit, we reviewed cases of 'florid reactive lymphoid hyperplasia' affecting this region. METHODS: The cases were retrieved and were investigated using a panel of immunohistochemical stains and PCR clonality studies. Cases were jointly assessed by a specialist ophthalmic pathologist and a haematopathologist. RESULTS: Eight cases were retrieved from file, and all showed morphological features that fell within the spectrum of changes seen in PTGC. A diagnosis of PTGC was made in cases with expanded germinal centres showing >90% infiltration by mantle cell lymphocytes. Cases where there were other PTGC features, but <90% infiltration by mantle lymphocytes, were classified as incomplete or focal PTGC. CONCLUSIONS: The authors observed the spectrum of changes previously described in nodal tissue, finding follicular hyperplasia, follicular lysis and PTGC in the orbit. They also identified one specimen that harboured a malignant lymphoma. The study demonstrated that lymphoid proliferations within the orbit can be difficult to evaluate. The authors recommend that such proliferations are investigated with a broad panel of immunohistochemical stains together with PCR where appropriate, and that there should be a low threshold for referral to a specialist haematopathologist.
AIMS: Progressive transformation of germinal centres (PTGC) is a reactive process of undetermined aetiology. Although usually seen as nodal disease, it can occur at extra-nodal sites, such as oral cavity, gastrointestinal tract and skin. To determine if PTGC occurs in the orbit, we reviewed cases of 'florid reactive lymphoid hyperplasia' affecting this region. METHODS: The cases were retrieved and were investigated using a panel of immunohistochemical stains and PCR clonality studies. Cases were jointly assessed by a specialist ophthalmic pathologist and a haematopathologist. RESULTS: Eight cases were retrieved from file, and all showed morphological features that fell within the spectrum of changes seen in PTGC. A diagnosis of PTGC was made in cases with expanded germinal centres showing >90% infiltration by mantle cell lymphocytes. Cases where there were other PTGC features, but <90% infiltration by mantle lymphocytes, were classified as incomplete or focal PTGC. CONCLUSIONS: The authors observed the spectrum of changes previously described in nodal tissue, finding follicular hyperplasia, follicular lysis and PTGC in the orbit. They also identified one specimen that harboured a malignant lymphoma. The study demonstrated that lymphoid proliferations within the orbit can be difficult to evaluate. The authors recommend that such proliferations are investigated with a broad panel of immunohistochemical stains together with PCR where appropriate, and that there should be a low threshold for referral to a specialist haematopathologist.