Conjunctival squamous intraepithelial neoplasia and its differential diagnosis.

Conjunctival squamous intraepithelial neoplasia (CSIN) represents the in situ precursor of squamous cell carcinoma. The graded severity of intraepithelial dysplasia is considered a measure of risk for progression to invasive carcinoma. The range of cytoarchitectural changes in CSIN overlaps those of reactive atypia, squamous epithelial papilloma and in situ sebaceous carcinoma. Pseudoepitheliomatous hyperplasia and benign hereditary dyskeratosis of the conjunctiva are conditions without risk of neoplastic transform that are potentially mistaken for CSIN.

Periocular intraepithelial sebaceous neoplasia: critical appraisal of nomenclature and prognostic importance.

Intraepithelial sebaceous neoplasia in the forms (or subclassification) of pagetoid spread and carcinoma in situ is a common feature of periocular sebaceous carcinoma and is associated with less favourable outcomes. Seminal studies of periocular sebaceous carcinoma in the 1980s indicated that the two patterns of intraepithelial spread had differing influences on prognosis with pagetoid invasion being worse. Later studies reported conflicting results, but careful inspection of those studies revealed considerable variation in what was meant by pagetoid invasion. Different interpretations of pagetoid spread continue, leading to ambiguous results in clinical studies and miscommunication with potential unintended decisions affecting clinical management. This paper reviews the background leading to the frequent interchangeable use of pagetoid spread with in situ sebaceous carcinoma and how this problem confounds interpretation of clinical studies. The author recommends that for effective communication, all morphological patterns of in situ spread of sebaceous carcinoma fall under the term intraepithelial sebaceous neoplasia, which can be accompanied by subclassification whenever desired.

Histopathological evaluation of scleritis.

The sclera is an uncommon site of primary inflammation. Biopsy is infrequently employed in the evaluation of scleritis, but familiarity with its differential diagnosis is instrumental in ensuring efficient histological evaluation. This review provides a clinical overview of scleritis and describes the context in which scleral biopsy might arise. Most cases are associated with systemic autoimmune disease, but a sizeable proportion occur as an isolated disorder. Conditions mimicking autoimmune scleritis include infection and neoplasm. Histological patterns of inflammation in eyes removed surgically or at autopsy have been placed into three groups: (1) autoimmune scleritis characterised by varying mixtures of palisading granulomas, necrosis and vasculitis; (2) infectious scleritis, characterised by acute inflammation and necrosis; and (3) idiopathic scleritis, characterised by chronic non-specific inflammation with follicles and varying amounts of fibrosis. This traditional system of classification may be oversimplified. Aetiological or categorical classification is not always possible on small biopsies given the histopathological overlap of infectious and non-infectious scleritis.