Prolymphocytic leukemia of T-cell type, in relapse

This code signifies a diagnosis of prolymphocytic leukemia (PLL) specifically originating from T-lymphocytes, which has recurred after a period of remission or treatment. T-cell PLL is a rare and aggressive mature T-cell neoplasm characterized by a proliferation of small to medium-sized prolymphocytes. The "in relapse" indicator denotes that the disease has reactivated following prior treatment.

Use this code when documentation clearly indicates a diagnosis of T-cell prolymphocytic leukemia that has relapsed. This typically applies to patients who previously achieved remission and are now experiencing a recurrence of the disease, confirmed by laboratory findings and clinical assessment. Supporting documentation would include pathology reports, hematology consultations, and physician notes detailing the relapse.

• Ensure the documentation specifies "T-cell type" and "in relapse" to accurately assign this code.
• Distinguish from B-cell prolymphocytic leukemia (C91.5-) and other types of T-cell leukemias.
• Always sequence this code as the primary diagnosis when it is the reason for the encounter, unless another condition is explicitly identified as the primary reason for admission/visit.