A Case for Diagnosis

The patient is a 58 yo woman with asymptomatic lesions under breasts, in the axillae and groin.  She is on no medications,  She has breast cancer seven years ago treated with lumpectomy and chemotherapy (no radiation) and has been off therapy for 6 years.

O/E:  slightly hyperpigmented macules in affected areas.  KOH negative.

Clinical Photos:

Left axilla

Pathology:  2 representative punch biopsies were taken. 

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Report: Focal basal layer vacuolization, a mild superficial perivascular and focally band-like lymphocytic infiltrate with rare eosinophils, papillary dermal fibrosis, numerous melanophages, and telangiectasia, consistent with a lichenoid interface dermatitis with post-inflammatory hyperpigmentation.

NOTE: The differential diagnosis could include lichen planus (possibly lichen planus pigmentosus) or a lichenoid drug eruption.

Diagnosis: Lichen Planus Variant.  Is this annular atrophic lichen planus?

Reference:
Annular atrophic lichen planus.

Morales-Callaghan A Jr1, et. al. J Am Acad Dermatol. 2005 May;52(5):906-8.

Abstract: We describe a new case of annular atrophic lichen planus. Annular atrophic lichen planus is a rare variant of lichen planus that is clinically characterized by violaceous plaques of annular morphology with central atrophy and histopathologic findings of annular and atrophic lichen planus, respectively. There have been 4 cases of this entity reported previously.