Indolent CD30-Positive Extranodal NK/T Cell Lymphoma with Large Cell Transformation: Case Report and Literature Review.

The nasal type of extranodal natural killer (NK)/T-cell lymphoma (ENKL) is an aggressive form of non-Hodgkin's lymphoma. Although ENKL is most commonly seen in the midline of the nose, face and Waldeyer's ring, it can also occur in the skin, gastrointestinal tract, soft tissues and other parts of the body. Severe ENKL cases are accompanied by hemophagocytosis, with clinical manifestations such as high fever, hepatosplenomegaly, and decreased blood cell count. ENKL at different locations exhibits similar histological features and immunophenotypes, such as a strong affinity for T cell markers CD2 and CD56, cytotoxic molecules, as well as a strong positive for EBER after in situ hybridization. Although indolent ENKL is extremely rare, we hereby present a case study of primary NK/T cell lymphoma in the spinal canal with the initial manifestation of a diffuse growth of small cells, and the survival and recurrence details after 11 years, accompanied by CD30-positive large cell transformation. The patient's condition after treatment has improved and is currently in good health.