Corneal ulcer

A 62-year-old woman comes to the physician complaining of a “gritty” sensation in the eyes for the last several months. She states her eyes have also been increasingly itchy and red, and she also needs to chew food for a longer period of time in order to swallow it properly. Past medical history is significant for rheumatoid arthritis that is well managed with methotrexate. Vital signs are within normal limits. Physical examination shows redness of both eyes. Bilateral wrist and first metacarpophalangeal joints show mild swelling and tenderness. There is nontender, diffuse parotid gland enlargement bilaterally. Oral examination reveals mucosal atrophy and multiple dental caries. Ophthalmologic examination reveals decreased visual acuity in both eyes. A strip of litmus filter paper is folded at one end and inserted in the patient's lower eyelid; after 5 minutes, there is < 5 mm (normal > 15 mm) of moisture on the filter paper. Multiple corneal punctate spots are noted on fluorescein staining. Labial salivary gland biopsy would most likely show which of the following findings?