Alphabetic Index FY2027

C84.1

Sézary disease

FY2027Chapter 2: Neoplasms/C81–C96 Malignant neoplasms of lymphoid, hematopoietic and related tissue

Non-billable headerNot valid on its own. Use one of the more specific codes under it.

C84.1 is a non-billable ICD-10-CM code header for sézary disease. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are C84.10 Sézary disease, unspecified site; C84.11 Sézary disease, lymph nodes of head, face, and neck; C84.12 Sézary disease, intrathoracic lymph nodes; C84.13 Sézary disease, intra-abdominal lymph nodes and 7 more. Its coding notes include 1 Excludes1 entry and 4 Excludes2 entries.

Excludes1

Not coded here. The listed conditions generally should not be reported together.

Inherited from C84 Mature T/NK-cell lymphomas
  • personal history of non-Hodgkin lymphoma (Z85.72)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Also from chapter/block level (4 notes)
Inherited from C81–C96 Malignant neoplasms of lymphoid, hematopoietic and related tissue
  • Kaposi's sarcoma of lymph nodes (C46.3)
  • secondary and unspecified neoplasm of lymph nodes (C77.-)
  • secondary neoplasm of bone marrow (C79.52)
  • secondary neoplasm of spleen (C78.89)

Notes

Also from chapter/block level (8 notes)
Inherited from Chapter 2 Neoplasms
  • Functional activity
  • All neoplasms are classified in this chapter, whether they are functionally active or not. An additional code from Chapter 4 may be used, to identify functional activity associated with any neoplasm.
  • Morphology [Histology]
  • Chapter 2 classifies neoplasms primarily by site (topography), with broad groupings for behavior, malignant, in situ, benign, etc. The Table of Neoplasms should be used to identify the correct topography code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology (histologic type) is included in the category and codes.
  • Primary malignant neoplasms overlapping site boundaries
  • A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned.
  • Malignant neoplasm of ectopic tissue
  • Malignant neoplasms of ectopic tissue are to be coded to the site mentioned, e.g., ectopic pancreatic malignant neoplasms are coded to pancreas, unspecified (C25.9).

Alphabetic Index terms

Terms the official Alphabetic Index lists for this code. 2 entries

More specific codes under C84.1 11