D49 refers to Neoplasms of unspecified behavior, a category of neoplasms that either originate from hormone-secreting neuroendocrine cells and are confirmed to be benign (D3A), or those whose behavior—benign or malignant—cannot be clearly determined at diagnosis (D49). These codes help flag uncertain or low-risk tumors for observation and follow-up.

Symptoms

Incidental mass – Often found on imaging with no symptoms
Hormonal imbalance – Seen in benign neuroendocrine tumors (e.g., carcinoid, insulinoma)
Non-specific discomfort – Pressure or mild pain in tumor region
Flushing or diarrhea – Linked to hormonally active tumors
Stable growth – Tumors that remain unchanged over time
No systemic signs – Typically no weight loss, fever, or major dysfunction
Normal lab tests – Bloodwork may not show malignant indicators

Diagnosis

Diagnosis of Neoplasms of unspecified behavior involves imaging (CT, MRI, nuclear scans), hormonal testing (if neuroendocrine-related), and biopsy. These tumors are often monitored over time to assess behavior, growth, or potential need for intervention, especially if initial pathology results are inconclusive or benign.

ICD10 Code Usage

ICD10 code D49 is used when documentation requires classification of a neoplasm as benign or undefined in its behavior. It is important in surgical, endocrine, radiology, and oncology workflows to guide next steps, insurance documentation, and care planning.

Related Codes

D3A – Benign neuroendocrine tumors

FAQs

Q1: What is ICD10 code D49?
A: It refers to Neoplasms of unspecified behavior, used to document either benign neuroendocrine tumors (D3A) or neoplasms with unclear behavior (D49).

Q2: Are these cancer?
A: No, D3A is benign, and D49 is unspecified—neither are definitively malignant unless reclassified later.

Q3: Are these tumors removed?
A: Only if symptomatic, growing, or suspicious. Many are monitored over time.

Q4: What does “unspecified behavior” mean?
A: It means there isn’t enough evidence to classify the tumor as benign or malignant.

Q5: Should these be followed up?
A: Yes, regular surveillance is usually recommended to detect changes in behavior.

Conclusion

ICD10 code D49 is essential for accurately documenting Neoplasms of unspecified behavior. It supports clinical decision-making, follow-up care, and billing processes when a tumor is either confirmed benign (D3A) or its biological behavior remains uncertain (D49).