Purpose Reactive lymphoid hyperplasia (RLH), also called inflammatory pseudotumor, benign lymphoma or pseudolymphoma, is a benign and reversible enlargement of lymphoid tissue probably as a reaction to antigen hyperstimulation. RLH consists of dense sheets of small mature lymphocytes with the formation of primary and secondary follicles reminiscent of normal lymph node architecture. In this study we wanted to evaluate the clinical presentation of RLH on the ocular surface. Methods We reviewed 6 patients (3 males, 3 females) with RLH of the ocular surface. The mean age at the time of diagnosis was 28 yrs (range: 8 to 77 yrs). Paraffin sections were stained with H&E and PAS and further evaluated using immunohistochemistry. Results In 2 patients, RLH was confined to the caruncle. One patient presented with a large cyst‐like lesion, another one with a conjunctival nodule near the medial canthus, and in the oldest patient the RLH manifested itself as a pemphigoid‐like conjunctival lesion in the lower fornix. A 26‐years old female patient with a Non‐Hodgkin‐Lymphoma of the left conjunctiva developed conjunctival RLH one month later in the lower fornix of the fellow eye. Follow‐up (1‐11 yrs) was uneventful in all patients. Conclusion In our case series, RLH presented as a singular lesion with varying clinical morphology. Obviously, it has to be carefully distinguished from lymphoma and should be considered in the differential diagnosis even of cyst‐like lesions and at unusual sites such as the caruncle.

Purpose On histology, the crystalline lens is – especially in fetal and infant eyes ‐ an organ susceptible to numerous artifacts. Nevertheless, evaluation of the lens is often of paramount importance in the classification of fetal syndromes or forensic questions. Thus, the aim of our study is to evaluate various factors that might have an impact on lens histomorphology. Methods Our collection of eyes by now comprises more than 500 specimens from fetuses with a gestational age between 8 and 38 weeks, including a variety of syndroms. Apart from induced fetocid, death occured due to spontaneous abortion or post‐natally. Specimens were fixed in formalin, and in selected cases one eye was put into Karnovsky's solution for comparison. All systemic findings as well as data related to the termination procedure were recorded. ‐ Some individual cases shall be presented to demonstrate the variability of histopathologic findings. Results Most of the eyes revealed lens features different from the descriptions available in textbooks. At all ages, there were various morphologic changes particularly of the subcapsular cortex, compatible with cataractous lenses in the adult, while the well‐known phenomenon of an indentation at the posterior pole was seen especially in older fetuses. The difference in fixatives had only a moderate impact on structural alterations. Conclusion Alterations in fetal lens morphology are extremely frequent and variable. These can be due to delayed fixation, cutting artifacts and other variables and have to be carefully taken into account particularly when interpreting post‐mortem findings. The diagnosis of a fetal cataract should therefore only be made with great caution and not without a careful macroscopic evaluation.

Purpose IgG4‐related sclerosing disease is a systemic disease characterized histopathologically by extensive infiltration of various organs by IgG4‐positive plasma cells (and T lymphocytes). Frequently associated with elevation of serum IgG4 levels, major clinical manifestations are apparent in organs in which tissues fibrosis is induced, e.g. in the pancreas. Some variants of inflammatory pseudotumour of the orbit reveal histopathologically a close relationship to multifocal fibrosclerosis. We therefore evaluated the presence of IgG4‐positive plasma cells in this disease to possibly find an association with systemic IgG4‐related sclerosis. Methods We investigated 10 specimens of orbital pseudotumours that had been diagnosed by the Dep. of Pathology using HE&PAS staining. Immunohistochemical labeling was performed using antibodies against κ‐ and λ‐chains, IgA, IgD, IgM, IgG, and IgG4 and the staining intensity was independently evaluated by MCH and HPF. Results 3 specimens showed an increased immunoreactivity with anti‐IgG4 (2/3 intensive staining, 1/3 moderate staining). In addition, in these specimens there was only a slight expression of IgA, IgD and IgM. With regard to all specimens, plasma cells secretion of λ‐chains was insignificantly stronger than that of κ‐chains. Conclusion This being the first investigation of IgG4‐immunostaining in ocular pseudotumours, our results indicate a possible relationship between this disease entity and IgG4‐related sclerosing disease. Further investigations including IgG4 serum levels and a more detailed history regarding associated systemic disease is warranted.