Combined CLL and granulomatous dermatitis at prior sites of herpes zoster was first reported in 1990. 8 In 1995, Cerroni et al 9 reported a series of 5 patients with cutaneous CLL following herpes zoster or herpes simplex virus infection. Three of those patients also demonstrated granuloma formation. 9 Establishing a new diagnosis of CLL from a biopsy of postzoster granulomatous dermatitis with an associated lymphoid infiltrate also has been reported. 10 Cerroni et al 9 postulated that cutaneous CLL in post-herpes zoster scars may occur more frequently than reported due to misdiagnoses of CLL as pseudolymphoma. Two additional cases of postherpetic cutaneous CLL and granulomatous dermatitis have been reported since 1995. 7,10
Diagnosis of Multiple PHIRs
The presence of 3 concurrent PHIRs is rare. The patient in this report had postzoster cutaneous CLL with an associated granulomatous dermatitis and medium-vessel vasculitis. One other case with these 3 findings was reported by Elgoweini et al. 7 Overlooking important diagnoses when multiple findings are present in a biopsy can lead to diagnostic delay and incorrect treatment; we highlighted the importance of careful examination of biopsies in PHIRs to ensure diagnostic accuracy. In cases of postzoster granulomatous dermatitis, assessment of the lymphocytic component should not be overlooked. The presence of a dense lymphocytic infiltrate should raise the possibility of a lymphoproliferative disorder such as CLL, even in patients with no prior history of lymphoma. If initial immunostaining discloses a predominantly B-cell infiltrate, additional immuno-stains (eg, CD5, CD23, CD43) and/or genetic testing for monoclonality should be pursued.
Conclusion
Clinicians and dermatopathologists should be aware of the multiplicity of postherpetic isotopic responses and consider immunohistochemical stains to differentiate between a genuine lymphoma such as CLL and pseudolymphoma in PHIRs with a lymphoid infiltrate.