Neoplasm Of Uncertain Behavior Of Endocrine Glands ICD-10-CM Coding

ICD-10-CM Code For Neoplasm Of Uncertain Behavior Of Endocrine Glands: Group Overview

The International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) code group D44 includes neoplasms of endocrine glands whose behavior is uncertain, covering lesions of the thyroid, adrenal, pituitary, and other hormone-producing tissues that cannot be definitively classified as benign or malignant. These ICD-10-CM diagnosis codes are used to document clinical scenarios where histology or clinical follow-up does not confirm benignity or malignancy, capturing diagnostic uncertainty and organ-specific involvement. Accurate coding within the ICD-10-CM D44 group supports proper claim adjudication, complete clinical documentation, and appropriate reimbursement.

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ICD-10-CM D44: Neoplasm Of Uncertain Behavior Of Endocrine Glands Overview

This group represents neoplasms in endocrine glands whose behavior (benign or malignant) is uncertain, including lesions of the thyroid, adrenal, pituitary, and other endocrine tissues. These diagnoses target the endocrine system and related hormone-producing organs. Accurate coding matters for clinical records and reimbursement because it clarifies diagnostic uncertainty and supports appropriate claim processing.

When to Use

Use a code from this group when a clinician documents an endocrine gland neoplasm with uncertain behavior due to indeterminate histology or pending diagnostic workup. These codes apply during diagnostic evaluation, biopsy results that are inconclusive, or when follow-up is required to establish behavior.

ICD-10-CM Codes

11 rows

ICD-10-CM Code	Description
D44.0	Neoplasm of uncertain behavior of thyroid gland
D44.10	Neoplasm of uncertain behavior of unspecified adrenal gland
D44.11	Neoplasm of uncertain behavior of right adrenal gland
D44.12	Neoplasm of uncertain behavior of left adrenal gland
D44.2	Neoplasm of uncertain behavior of parathyroid gland
D44.3	Neoplasm of uncertain behavior of pituitary gland
D44.4	Neoplasm of uncertain behavior of craniopharyngeal duct
D44.5	Neoplasm of uncertain behavior of pineal gland
D44.6	Neoplasm of uncertain behavior of carotid body
D44.7	Neoplasm of uncertain behavior of aortic body and other paraganglia
D44.9	Neoplasm of uncertain behavior of unspecified endocrine gland

DRG Code	Description
054	Nervous System Neoplasms with MCC
055	Nervous System Neoplasms without MCC
643	Endocrine Disorders with MCC
644	Endocrine Disorders with CC
645	Endocrine Disorders without CC/MCC

DRG Code

Description

054

Nervous System Neoplasms with MCC

055

Nervous System Neoplasms without MCC

643

Endocrine Disorders with MCC

644

Endocrine Disorders with CC

645

Endocrine Disorders without CC/MCC

Typical Clinical Scenarios

An adult patient in an outpatient endocrinology clinic is found on imaging and biochemical workup to have a solitary thyroid nodule with indeterminate cytology on fine-needle aspiration (atypia of undetermined significance). The clinician orders serial ultrasound surveillance and refers for possible repeat biopsy because malignancy cannot be excluded; a neoplasm of uncertain behavior code is assigned when the lesion’s behavior remains unconfirmed. Typical codes: D44.0.
A middle-aged patient presents to the emergency department with signs of adrenal hormone excess (hypertension, episodic headaches, sweating) and imaging reveals an adrenal mass of uncertain malignant potential; initial labs and imaging cannot definitively classify it as benign or malignant. The patient is admitted for further endocrine evaluation and perioperative planning while the tumor’s behavior is undetermined, prompting assignment of an uncertain behavior neoplasm code for the endocrine gland. Typical codes: D44.1, D44.2.
An elderly patient with a history of a pancreatic neuroendocrine lesion under observation develops new, progressive local symptoms (abdominal pain and weight loss) but biopsy is inconclusive for malignancy; the lesion is being managed as an indeterminate endocrine neoplasm alongside other comorbidities. Because the tumor’s malignant potential remains unclear and it affects care planning and surveillance, a neoplasm of uncertain behavior code is used. Typical codes: D44.3, D44.4.

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.

DRG Code	Description
054	Nervous System Neoplasms with MCC
055	Nervous System Neoplasms without MCC
643	Endocrine Disorders with MCC
644	Endocrine Disorders with CC
645	Endocrine Disorders without CC/MCC

An adult patient in an outpatient endocrinology clinic is found on imaging and biochemical workup to have a solitary thyroid nodule with indeterminate cytology on fine-needle aspiration (atypia of undetermined significance). The clinician orders serial ultrasound surveillance and refers for possible repeat biopsy because malignancy cannot be excluded; a neoplasm of uncertain behavior code is assigned when the lesion’s behavior remains unconfirmed. Typical codes: D44.0.
A middle-aged patient presents to the emergency department with signs of adrenal hormone excess (hypertension, episodic headaches, sweating) and imaging reveals an adrenal mass of uncertain malignant potential; initial labs and imaging cannot definitively classify it as benign or malignant. The patient is admitted for further endocrine evaluation and perioperative planning while the tumor’s behavior is undetermined, prompting assignment of an uncertain behavior neoplasm code for the endocrine gland. Typical codes: D44.1, D44.2.
An elderly patient with a history of a pancreatic neuroendocrine lesion under observation develops new, progressive local symptoms (abdominal pain and weight loss) but biopsy is inconclusive for malignancy; the lesion is being managed as an indeterminate endocrine neoplasm alongside other comorbidities. Because the tumor’s malignant potential remains unclear and it affects care planning and surveillance, a neoplasm of uncertain behavior code is used. Typical codes: D44.3, D44.4.

ICD-10-CM Code For Neoplasm Of Uncertain Behavior Of Endocrine Glands: Group Overview

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ICD-10-CM D44: Neoplasm Of Uncertain Behavior Of Endocrine Glands Overview

ICD-10-CM Code For Neoplasm Of Uncertain Behavior Of Endocrine Glands: Group Overview

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ICD-10-CM D44: Neoplasm Of Uncertain Behavior Of Endocrine Glands Overview

When to Use

ICD-10-CM Codes

DRG Codes

Typical Clinical Scenarios

Related Codes

References

When to Use

ICD-10-CM Codes

DRG Codes

Typical Clinical Scenarios

Related Codes

References

ICD-10-CM Code For Neoplasm Of Uncertain Behavior Of Endocrine Glands: Group Overview

Sign up for ICD-10-CM Code For Neoplasm Of Uncertain Behavior Of Endocrine Glands: Group Overview policy alerts

ICD-10-CM D44: Neoplasm Of Uncertain Behavior Of Endocrine Glands Overview

ICD-10-CM Code For Neoplasm Of Uncertain Behavior Of Endocrine Glands: Group Overview

Sign up for ICD-10-CM Code For Neoplasm Of Uncertain Behavior Of Endocrine Glands: Group Overview policy alerts

ICD-10-CM D44: Neoplasm Of Uncertain Behavior Of Endocrine Glands Overview

When to Use

ICD-10-CM Codes

DRG Codes

Typical Clinical Scenarios

Related Codes

Which ICD-10-CM codes are included in the D44 group for endocrine neoplasms of uncertain behavior?

When should a coder assign a D44 group code instead of a benign or malignant neoplasm code?

How does accurate coding in the `D44` group affect claims and documentation?

Which endocrine organs are specifically represented in the D44 code list?

Are there related DRGs to consider when coding D44 diagnoses for inpatient cases?

References

When to Use

ICD-10-CM Codes

DRG Codes

Typical Clinical Scenarios

Related Codes

Which ICD-10-CM codes are included in the D44 group for endocrine neoplasms of uncertain behavior?

When should a coder assign a D44 group code instead of a benign or malignant neoplasm code?

How does accurate coding in the `D44` group affect claims and documentation?

Which endocrine organs are specifically represented in the D44 code list?

Are there related DRGs to consider when coding D44 diagnoses for inpatient cases?

References