polymorphonuclear leukocyte response to gonococcal conjunctivitis. Note the intracellular gram-negative diplococci (arrow). D, A case of Moraxella lacunata angular conjunctivitis demonstrating the bacilli, which often are found in pairs (arrow). E, Chlamydia, conjunctival scraping, Giemsa stain. The cytoplasmic inclusion body (asterisk), composed of multiple chlamydial organisms, can be seen capping the nucleus (N). A distinct space separates the inclusion body from the nuclear chromatin.
Figure 5-9 Ocular cicatricial pemphigoid (OCP). A, Clinical appearance. B, Histology shows epithelial bullae (arrows) and dense plasma cell infiltrate in the substantia propria (arrowheads). C, Immunofluorescent staining of the epithelial basement
membrane (arrowheads) in OCP. (Part A courtesy of Andrew J.W. Huang, MD; part B courtesy of George J. Harocopos, MD.)
Pyogenic Granuloma
A pyogenic granuloma appears as a reddish nodular elevation on the ocular surface, typically occurring in association with a chalazion (on the palpebral conjunctiva), or at a site of prior accidental or surgical trauma. Classic examples of the latter include a site of strabismus surgery (at the muscle insertion), retinal surgery, or enucleation. The name of this condition is somewhat of a misnomer because the lesion is not necrotic, nor is it a true granuloma. Rather, it consists of granulation tissue, that is, a pedunculated mass composed of a mixture of acute and chronic inflammatory cells, with proliferating capillaries that classically form a “spoke-wheel” pattern (Fig 5-10).
Degenerations
Pinguecula and Pterygium
A pinguecula is a small, yellowish nodule, often bilateral, situated at the nasal and/or temporal limbus (Fig 5-11A). It is a manifestation of actinic damage (exposure to sunlight) and is therefore more common with advancing years. Pingueculae are typically asymptomatic and may generally be observed. On histology, the stromal collagen shows fragmentation and basophilic degeneration called elastotic degeneration because the degenerated collagen stains positively with histochemical stains for elastic fibers such as the Verhoeff–van Gieson (VVG) stain (Fig 5-11B, C). See Chapter 6 for a discussion of actinic keratopathy, which may be regarded as the corneal analogue of pinguecula.
Figure 5-10 Pyogenic granuloma. A, Clinical appearance, at a site of prior strabismus surgery. B, Histology at low magnification shows a pedunculated mass of granulation tissue, with a “spoke-wheel” vascular pattern. C, High magnification shows a mixture of acute and chronic inflammatory cells: note neutrophils (N), both within the lumen of blood vessels and also infiltrating the tissue; chronic inflammatory cells are also present, predominantly lymphocytes (L) in this field. (Part A
courtesy of Gregg T. Lueder, MD; parts B and C courtesy of George J. Harocopos, MD.)
A pterygium has similar etiology and location, but it differs from a pinguecula in that it exhibits prominent vascularity and also encroaches onto the cornea in a winglike fashion (Fig 5-12A). Pterygia are excised when they threaten the visual axis, thereby becoming visually significant, or when they cause chronic irritation. Histology typically shows elastotic degeneration, as in a pinguecula, but also shows prominent blood vessels, correlating with the vascularity seen clinically
(Fig 5-12B, C), and variable degrees of chronic inflammation. So-called recurrent pterygia may completely lack the histologic feature of elastotic degeneration and are more accurately classified as an exuberant fibroconnective tissue response.
In pingueculae and pterygia, the overlying epithelium may exhibit mild squamous metaplasia, for example, loss of goblet cells and surface keratinization. Some studies have demonstrated that there is abnormal expression of Ki-67 (a proliferation marker) and of tumor suppressor genes such as p53 and p63, as well as loss of heterozygosity and microsatellite instability. Thus, as with actinic damage to the skin, there is always the potential for future malignant transformation, although this occurs only rarely in association with pingueculae and pterygia. When conjunctival squamous neoplasia does arise, however, it often occurs overlying an area of preexisting elastotic degeneration. If features such as epithelial hyperplasia, nuclear hyperchromasia and pleomorphism, and excessive mitotic figures are identified in an excised pinguecula or pterygium, then a diagnosis of ocular surface squamous neoplasia should be assigned (see the section “Ocular surface squamous neoplasia” under Squamous Lesions). See also BCSC Section 8, External Disease and Cornea.
Dong N, Li W, Lin H, et al. Abnormal epithelial differentiation and tear film alteration in pinguecula. Invest Ophthalmol Vis Sci. 2009;50(6):2710–2715.
Figure 5-11 Pinguecula. A, Clinical appearance adjacent to the nasal and temporal limbus. B, On histology, note the acellular, slightly basophilic material in the substantia propria (asterisk) and thick curly fibers (arrows) indicative of elastotic degeneration. C, With VVG stain for elastin, the material stains black. (Parts A and C courtesy of George J. Harocopos, MD; part B
courtesy of Hans E. Grossniklaus, MD.)
Amyloid Deposits
Amyloid deposition in the conjunctiva is most commonly an idiopathic, primary localized process seen in healthy young and middle-aged adults. Less often, it occurs secondary to preexisting, longstanding inflammation, such as with trachoma (ie, secondary localized amyloidosis). Occasionally, conjunctival amyloidosis may occur secondary to a systemic disease such as multiple myeloma. Localized or systemic amyloidosis may also involve the orbit. Clinically, conjunctival amyloidosis typically presents as a salmon-colored nodular elevation (Fig 5-13). The color may resemble the