Pathology quiz case 2. Pemphigus vulgaris (PV).

A 48-YEAR-OLD man presented to the emergency department with a 2-day history of hemoptysis and an inability to tolerate oral intake because of severe dysphagia and odynophagia. He also reported a 2-week history of symptom progression in association with oral ulcerations, worsening dyspepsia, nausea, and hoarseness, as well as a 1-week history of fevers, chills, and night sweats. His medical history was unremarkable except for excessivealcohol and tobaccoabuse.Hewas takingnomedications and denied any drug use. He was a thin man who appeared mildly distressed, with notable pallor and loss of skin turgor. Initial vital signs revealed tachycardia (pulse rate, 114/min) and a temperature of 38.2°C, with stable blood pressure (139/69 mm Hg) and respiration. Ophthalmologic evaluation revealed bilateral conjunctival injection. The oral examination revealed desquamative mucositis involving the palate, wet labial mucosa, bilateral buccal mucosa, floor of the mouth, tongue, fauces, and posterior pharyngeal wall, with sparing of the gingiva (Figure 1). A positive Nikolsky sign and a negative pathergy reaction were noted. Flexible laryngoscopy revealed extension of mucosal inflammation, with blistering and ulceration involving the hypopharynx and larynx as well. Flexible esophagoscopy revealed erosive esophagitis that was similar in appearance to and contiguous with oropharyngeal lesions. A biopsy was performed at the margin of a lower labial mucosal blister, and the specimen was submitted for microscopic examination (Figure 2 and Figure 3) and immunofluorescence (Figure4). Immunostains were negative for herpesvirus 1 and 2. Laboratory values included a white blood cell count of 5.6 10/μL, with 69% neutrophils, 14.6% monocytes, and 13.4% lymphocytes. Serologic tests were negative for human immunodeficiency virus 1 and 2, and the CD4 count was 1848/μL. The human leukocyte antigen phenotype revealed DR6 antigen expression, and the circulating anti–epidermal antibody IgG titers were elevated. A complete dermatologic evaluation revealed no evidence of cutaneous lesions. What is your diagnosis?