Primary cutaneous B-cell lymphoblastic lymphoma in children. Report of two cases.

Precursor B-cell lymphoblastic lymphoma (B-LBL) is an uncommon high-grade neoplasm. Primary cutaneous B-LBL is uncommon and clinical diagnosis is difficult. We report two cases of primary cutaneous B-LBL that had initially been diagnosed as an infected dermoid cyst and lipoma, respectively, and referred for excision. The cases demonstrate the importance of biopsy and histopathologic examination of subcutaneous tumors to guide appropriate therapy.