D47.09 Other mast cell neoplasms of uncertain behavior

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applicable to

• Extracutaneous mastocytoma
• Mast cell tumor NOS
• Mastocytoma NOS
• Mastocytosis NOS

Applies from D47.0 Mast cell neoplasms of uncertain behavior

Excludes1 (never code together)

• congenital cutaneous mastocytosis (Q82.2)
• histiocytic neoplasms of uncertain behavior (D47.Z9)
• malignant mast cell neoplasm (C96.2-)

Risk adjustment (HCC)

• RxHCC V08: HCC 21 — Lymphomas and Other Hematologic Cancers

MS-DRG index

Defines the logic of DRG(s) 820-822 in MDC 17.

Approximate ICD-9-CM (GEMs)

• 238.5 Neoplasm of uncertain behavior of histiocytic and mast cells (approximate)

Code annotations containing back-references to D47.09

Back-references to D47.09

• Type 1 Excludes: D47.01 Cutaneous mastocytosis ("extracutaneous mastocytoma (D47.09)")
• Type 1 Excludes: D89.4 Mast cell activation syndrome and related disorders ("mastocytoma NOS (D47.09)")
• Type 1 Excludes: D89.4 Mast cell activation syndrome and related disorders ("other mast cell neoplasms of uncertain behavior (D47.09)")

Diagnosis Index entries for D47.09

• Mast cell › neoplasm › of uncertain behavior NEC
• Mast cell › tumor
• Mastocytoma (extracutaneous)
• Mastocytosis
• Neoplasm, neoplastic › mast cell, of uncertain behavior NEC
• Tumor › mast cell

Nearby codes

• D47 Other neoplasms of uncertain behavior of lymphoid, hematopoietic and related tissue
• D47.0 Mast cell neoplasms of uncertain behavior
• D47.01 Cutaneous mastocytosis
• D47.02 Systemic mastocytosis
• D47.09 Other mast cell neoplasms of uncertain behavior (this code)
• D47.1 Chronic myeloproliferative disease
• D47.2 Monoclonal gammopathy
• D47.3 Essential (hemorrhagic) thrombocythemia
• D47.4 Osteomyelofibrosis
• D47.Z Other specified neoplasms of uncertain behavior of lymphoid, hematopoietic and related tissue