Cutaneous lymphoma or benign lesion?
A 66-year-old man presented with an erythematous nodule on the distal ulnar aspect of his forearm, consistent with a pyogenic granuloma on inspection. The lesion had grown in diameter from 5 mm to 30 mm over a
few months, was nonulcerated and expressed a
small amount of serous luid (Figure 1A).
He reported a 30-year history of similar lesions that
had spontaneously resolved. Biopsy results from previous lesions had been consistent with inlamed seborrheic keratosis. Complete excisional biopsy of the current lesion showed a regressing CD30-positive lymphoproliferative disorder with pseudocarcinomatous hyperplasia.
We referred our patient to a lymphoma clinic for
staging and treatment. Bone marrow biopsy and
computed tomography (CT) of his neck, thorax,
abdomen and pelvis were normal. No further
treatment was required after the initial surgical
excision; however, the patient was advised to
return for routine surveillance. A subsequent
biopsy of a new lesion showed similar features
and lymphomatoid papulosis was diagnosed.
Although lymphomatoid papulosis is rare,
with an estimated incidence of one to two
instances per million, dome-shaped papules that occasionally characterize it can mimic numerous common skin conditions, including pyogenic granuloma. Lymphomatoid papulosis may also present with multiple lesions, which may be confused with reactions to insect bites and folliculitis.
These lesions must undergo excisional biopsy for accurate evaluation. Lymphomatoid papulosis is part of a spectrum of CD30-positive lymphoproliferative disorders. It presents as spontaneously regressing papules and nodules that recur over decades. Because lymphoma develops in 10%–19% of patients, regular surveillance is required.