Abstract

A 2-year-old female presented with an erythematous, ulcerated, firm nodule on her right abdomen that had been enlarging for six weeks. She had also developed a right upper chest nodule two weeks prior to her presentation. Pathology revealed a proliferation of atypical cells throughout the dermis extending into the subcutaneous fat and muscle.  The cells were pleiomorphic with prominent nucleoli and numerous mitoses. The neoplastic cells were positive for CD30, ALK-1, CD7, EMA, Granzyme B, Perforin, Ki-67 (80-90%), BCL-6 (weakly), MUM1 (weakly), and MYC (weakly). The cells were negative for TdT, CD20, CD5, CD8, CD3, CD4, CD10, BCL2, Cyclin D1, CD21, TIA1, Beta F1, and EBV EBER in situ. This was consistent with the diagnosis of ALK-1 positive anaplastic large cell lymphoma (ALCL). Lumbar puncture and bone marrow biopsy were both negative for malignancy. PET scan showed two masses, both greater than five centimeters, on the right chest wall and right abdominal wall and a hypermetabolic right hilar lymph node. The patient is currently undergoing chemotherapy. ALCL is a rare type of non-Hodgkin lymphoma. Most pediatric patients present at an advanced stage, commonly with extranodal disease. Pathology shows large pleiomorphic cells that stain strongly for CD30. Systemic disease is typically ALK-1 positive, whereas primary cutaneous ALCL is usually ALK-1 negative. Chemotherapeutic regimens have a 75% event-free survival rate in pediatric ALK-1 positive ALCLs. We present a case of a young child with ALK-1 positive lymphoma with disease limited to the skin and soft tissue along with minimal lymph node involvement.