Enlarged lymph nodes (R59) ICD-10-CM
The R59 code range covers enlarged lymph nodes with 4 ICD-10-CM diagnosis codes. 3 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Includes
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
- swollen glands
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Codes in the R59 Range 4 codes · 3 billable
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the R59 range.
AIDS-Related Complex
A prodromal phase of infection with the human immunodeficiency virus (HIV). Laboratory criteria separating AIDS-related complex (ARC) from AIDS include elevated or hyperactive B-cell humoral immune responses, compared to depressed or normal antibody reactivity in AIDS; follicular or mixed hyperplasia in ARC lymph nodes, leading to lymphocyte degeneration and depletion more typical of AIDS; evolving succession of histopathological lesions such as localization of Kaposi's sarcoma, signaling the transition to the full-blown AIDS.
Castleman Disease
Large benign, hyperplastic lymph nodes. The more common hyaline vascular subtype is characterized by small hyaline vascular follicles and interfollicular capillary proliferations. Plasma cells are often present and represent another subtype with the plasma cells containing IgM and IMMUNOGLOBULIN A.
HIV
Human immunodeficiency virus. A non-taxonomic and historical term referring to any of two species, specifically HIV-1 and/or HIV-2. Prior to 1986, this was called human T-lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV). From 1986-1990, it was an official species called HIV. Since 1991, HIV was no longer considered an official species name; the two species were designated HIV-1 and HIV-2.
HIV Antibodies
Antibodies reactive with HIV ANTIGENS.
HIV Antigens
Antigens associated with specific proteins of the human adult T-cell immunodeficiency virus (HIV); also called HTLV-III-associated and lymphadenopathy-associated virus (LAV) antigens.
Immunoblastic Lymphadenopathy
A disorder characterized by proliferation of arborizing small vessels, prominent immunoblastic proliferations and amorphous acidophilic interstitial material. Clinical manifestations include fever, sweats, weight loss, generalized lymphadenopathy and frequently hepatosplenomegaly.
Lymph Nodes
They are oval or bean shaped bodies (1 - 30 mm in diameter) located along the lymphatic system.
Lymphadenopathy
Disease of LYMPH NODES which are abnormal in size, number or consistency.
Rickettsia
A genus of gram-negative, aerobic, rod-shaped bacteria often surrounded by a protein microcapsular layer and slime layer. The natural cycle of its organisms generally involves a vertebrate and an invertebrate host. Species of the genus are the etiological agents of human diseases, such as typhus.
Spotted Fever Group Rickettsiosis
A group of arthropod-borne diseases caused by spotted fever bio-group members of RICKETTSIA. They are characterized by fever, headache, and petechial (spotted) rash.
About the R59 Code Range
ICD-10 code R59 and its subcategories classify various forms of enlarged lymph nodes, a condition where lymph nodes swell due to infection, inflammation, or other causes. These codes are used to specify the location and extent of lymph node enlargement in medical records.
The primary code R59 covers general cases of enlarged lymph nodes. R59.0 identifies localized enlarged lymph nodes, corresponding to specific areas such as cervical, axillary, or abdominal lymphadenopathy, with common synonyms like submandibular lymphadenopathy or mediastinal lymphadenopathy helping coders link terms like “facial lymphadenopathy” or “scalene lymphadenopathy” to this code. R59.1 refers to generalized enlarged lymph nodes, involving widespread lymphadenopathy, which may be described as superficial or deep lymphadenopathy, including persistent generalized lymphadenopathy often seen in viral infections like HIV. R59.9 is used when the enlarged lymph nodes are unspecified, capturing terms such as “lymphoid hyperplasia,” “Castleman disease,” or “shotty lymph node.” Understanding these distinctions ensures accurate documentation of lymph node enlargement in clinical and billing contexts, supporting precise diagnosis and treatment planning.
Questions About This Page
How many billable codes are in the R59 range?
Of the 4 codes in this range, 3 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the R59 range classify?
The range classifies enlarged lymph nodes. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
