C. Good syndrome
Histopathologic examination revealed epidermal acanthosis with scattered necrotic keratinocytes, basal-layer vacuolation, and a band-like lymphohistiocytic infiltrate in the papillary dermis. Direct immunofluorescence examination showed shaggy fibrinogen deposition along the dermoepidermal junction.
Because of the findings of thymoma, hypogammaglobulinemia, lichenoid oral lesions, and diarrhea, Good syndrome was suspected. A study of the lymphocyte populations revealed a decrease in the total B lymphocyte count and an increase in CD8+ T count, with an inverted CD4:CD8 ratio. These data supported the diagnosis of Good syndrome.
After a thymectomy was performed, the patient’s diarrheal episodes showed a transitory improvement; however, the oral lichenoid lesions persisted. Replacement therapy with immunoglobulins was initiated along with 0.4% tacrolimus oral rinses. After 2 years of follow-up, the lichenoid lesions remained unchanged. Nevertheless, the patient did not experience any new infectious episodes since initiation of treatment with immunoglobulins.