Ocular Surface Fibroma: Clinical, Histopathological, and Immunohistochemical Features of 10 Cases.

AIM: To describe the clinical, histological, and immunohistochemical (IHC) features of a series of 10 cases of ocular surface fibroma (OSF) and correlate the findings with other similar histological entities. METHOD: The patient demographics and features of the lesions were analysed from the clinical notes. All cases in the series had routine diagnostic excisional biopsies with standard histopathological and IHC evaluation. Each case was analysed by histology and immunohistochemistry with antibodies to: CD34, Factor XIIIa, desmin, smooth muscle actin, S100, Melan-A, ß-catenin, neurofilament, and Ki67. RESULTS: OSF occurred on the bulbar, tarsal, or forniceal conjunctiva, and typically presented as a white, pink, or yellow sheet-like or nodular lesion. The most common symptom was irritation or a foreign-body sensation. Lesions ranged in size from 4 to 13 mm. Only 1/10 cases showed a recurrence after an incomplete excision. Histologically, OSF comprised bland spindle cells in a collagen stroma. The spindle cells were CD34-positive (in 10/10 cases) and a smaller subset was positive for Factor XIIIa (6/10 cases). Normal resident spindle cells in the conjunctival stroma, Tenon's capsule, and tarsal plate were positive for CD34 and Factor XIIIa, implicating these cells in the origin of OSF. CONCLUSION: OSF is a benign lesion of resident CD34- and Factor XIIIa-positive spindle cells in the conjunctiva and Tenon's capsule. We have called to attention another lesion to be included by clinicians in the differential diagnosis of benign ocular surface lesions composed of CD34- and Factor XIIIa-positive spindle cells.

Keratin dynamics: modeling the interplay between turnover and transport.

Keratin are among the most abundant proteins in epithelial cells. Functions of the keratin network in cells are shaped by their dynamical organization. Using a collection of experimentally-driven mathematical models, different hypotheses for the turnover and transport of the keratin material in epithelial cells are tested. The interplay between turnover and transport and their effects on the keratin organization in cells are hence investigated by combining mathematical modeling and experimental data. Amongst the collection of mathematical models considered, a best model strongly supported by experimental data is identified. Fundamental to this approach is the fact that optimal parameter values associated with the best fit for each model are established. The best candidate among the best fits is characterized by the disassembly of the assembled keratin material in the perinuclear region and an active transport of the assembled keratin. Our study shows that an active transport of the assembled keratin is required to explain the experimentally observed keratin organization.

Reversible canal wall down mastoidectomy for acquired cholesteatomas: preliminary results.

OBJECTIVES: The educational objectives were to discuss a new technique to manage acquired cholesteatomas and to compare this with standard approaches used for cholesteatoma removal. The study objective was to determine the feasibility of using a new approach, the reversible canal wall down approach, in conjunction with bone cement to remove acquired cholesteatomas and, potentially, preserve the ossicular chain. STUDY DESIGN: Retrospective review of five patients who underwent resection of their acquired cholesteatomas using a technique that maximizes exposure, yet preserves the posterior canal wall and, potentially, the ossicular chain. METHODS: In the setting of a tertiary otological referral center, five consecutive patients with acquired cholesteatomas underwent reversible canal wall down surgery. Four patients were male (ages, 41, 53, 26, and 10 y), and one patient was a woman [age, 51 y]). A reversible canal wall down mastoidectomy approach was used in the patients. Main outcome measures were intraoperative findings with respect to cholesteatoma removal and postoperative clinical examination, including postoperative audiograms. RESULTS: Five patients had dry ears postoperatively. One patient initially had granulation tissue forming on the posterior ear canal. This eventually resolved. The patients who had a postoperative audiogram after cholesteatoma resection with ossicular chain preservation noted an improvement or stabilization in their hearing. CONCLUSIONS: Using the reversible canal wall down approach in conjunction with bone cement, one is able to obtain excellent exposure of the cholesteatoma and, potentially, preserve the ossicular chain. This approach may be particularly useful in revision cholesteatoma surgery or in cases of acquired cholesteatoma in which the surgeon may be able to preserve the ossicular chain.