Benign lymphoplasmacytic plaque
What is benign lymphoplasmacytic plaque?
Benign lymphoplasmacytic plaque was first described in 2009, with few reported cases. It is defined by chronic skin lesions, either solitary or in clusters, that have characteristic dense lymphocytic and polyclonal plasma cell infiltrates on biopsy.
Benign lymphoplasmacytic plaque has also been called cutaneous lymphoplasmacytic lymphoma, pretibial lymphoplasmacytic plaque and primary cutaneous plasmacytosis.
Who gets benign lymphoplasmacytic plaque?
Benign lymphoplasmacytic plaque has mostly been reported to affect female children between the ages of 7 and 15. Isolated cases have been described in adult males over the age of 60. It seems to predominantly affect people of Caucasian descent, although cases have also been described in Japanese, African and South Asian (Indian) children.
What causes benign lymphoplasmacytic plaque?
The cause of benign lymphoplasmacytic plaque is unknown. Preceding trauma to the affected area has been noted in a few cases, but no direct correlation has been confirmed.
What are the clinical features of benign lymphoplasmacytic plaque?
Benign lymphoplasmacytic plaque presents as a solitary chronic, persistent and asymptomatic skin lesion that is resistant to topical and systemic treatment. Clusters of similar lesions may occur.
- The mean duration is 3 years.
- The lesion is a variable, reddish-brown, painless papule or a scaly plaque.
- They most often affect the lower legs, but may also arise on upper limbs and buttocks.
- There are usually no other lesions elsewhere, and there are no systemic symptoms.
How is benign lymphoplasmacytic plaque diagnosed?
The diagnosis of benign lymphoplasmacytic plaque is made by dermatopathology and clinicopathologic correlation. The defining, compulsory histological findings are:
- Dense lymphohistiocytic infiltrate
- The presence of large numbers of plasma cells
- Absence of clonality of plasma cells
- No atypical cells in the infiltrate
Other tests should be performed to rule out infections, specifically atypical mycobacteria, leishmaniasis, borreliosis, syphilis and fungal infections. The plasma cells must be tested for clonality to exclude the possibility of a lymphoproliferative disorder.
What is the treatment?
Benign lymphoplasmacytic plaque can be removed by surgical excision. Topical steroids and systemic steroids, intralesional steroid injection, partial removal by shave excision, and oral antibiotics have not proved successful.
What is the outcome for benign lymphoplasmacytic plaque?
It is uncertain how benign lymphoplasmacytic plaque progresses long term.