2026 ICD-10-CM Diagnosis Code D40.10Neoplasm of uncertain behavior of unspecified testis
ICD-10-CM Codes›C00–D49›D37-D48›D40
- Billable — Valid for Submission
- Not Chronic
D40.10 is a billable ICD-10-CM diagnosis code for neoplasm of uncertain behavior of unspecified testis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 715 through 716, 722 through 724. Coders also document this condition as gonadoblastoma. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neoplasms of unspecified nature or uncertain behavior.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Gonadoblastoma
- Gonadoblastoma of testis
- Granulosa cell tumor of testis of uncertain behavior
- Leydig cell tumor of testis of uncertain behavior
- Neoplasm of uncertain behavior of testicular sex cord
- Neoplasm of uncertain behavior of testis
- Neoplasm of uncertain behavior of undescended testis
- Sertoli cell tumor of testis
- Sex cord stromal tumor of testis of uncertain behavior
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- male - D40.10
- male - D40.10
- male - D40.10
- male - D40.10
- male - D40.10
- Tumor - See Also: Neoplasm, unspecified behavior, by site;
- Leydig cell - See: Neoplasm, uncertain behavior, by site;
- male - D40.10
- testicular - D40.10
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Androblastoma
- unspecified site
- male
- Arrhenoblastoma
- unspecified site
- male
- Gonadoblastoma
- unspecified site
- male
- Gonocytoma
- unspecified site
- male
- Gynandroblastoma
- unspecified site
- male
- Tumor
- Leydig cell
- unspecified site
- male
- Tumor
- testicular
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Gonadoblastoma
a complex neoplasm composed of a mixture of gonadal elements, such as large primordial germ cells, immature sertoli cells or granulosa cells of the sex cord, and gonadal stromal cells. gonadoblastomas are most often associated with gonadal dysgenesis, 46, xy.Gonadoblastoma
a mixed germ cell/sex cord-stromal tumor characterized by the presence of large germ cells which resemble seminoma cells and small cells which resemble sertoli or granulosa cells. it occurs in the testis and the ovary and is identified in children and adults. it is often associated with gonadal dysgenesis and abnormal karyotype.Ovarian Gonadoblastoma
a neoplasm that arises from the ovary and is composed of tissues that resemble dysgerminoma or seminoma and are admixed with sex cord tissues. it is found in children or young adults and usually is associated with secondary sex organs abnormalities. the majority of patients present as phenotypic females with virilization. the minority of patients present as phenotypic males with feminization. it typically affects both gonads. if a malignant germ cell component is present, it may metastasize to other anatomic sites.Testicular Gonadoblastoma
a testicular mixed germ cell-sex cord-stromal tumor. it is usually associated with mixed gonadal dysgenesis and ambiguous genitalia. it is characterized by the presence of nests of large neoplastic germ cells and immature cells that resemble sertoli cells.
Table of NeoplasmsClinical
Anatomical sites in the Table of Neoplasms that reference this code family.
| Site | Malig. Primary | Malig. Secondary | Ca in situ | Benign | Uncertain | Unspec. |
|---|---|---|---|---|---|---|
| testis, testes | C62.9 | C79.82 | D07.69 | D29.2 | D40.1 | D49.59 |
| testis, testes › descended | C62.1 | C79.82 | D07.69 | D29.2 | D40.1 | D49.59 |
| testis, testes › ectopic | C62.0 | C79.82 | D07.69 | D29.2 | D40.1 | D49.59 |
| testis, testes › retained | C62.0 | C79.82 | D07.69 | D29.2 | D40.1 | D49.59 |
| testis, testes › scrotal | C62.1 | C79.82 | D07.69 | D29.2 | D40.1 | D49.59 |
| testis, testes › undescended | C62.0 | C79.82 | D07.69 | D29.2 | D40.1 | D49.59 |
| testis, testes › unspecified whether descended or undescended | C62.9 | C79.82 | D07.69 | D29.2 | D40.1 | D49.59 |
Patient EducationClinical
Testicular Cancer
Testicular cancer is a cancer that develops in the tissues of one or both testicles. The testicles, or testes, are part of the male reproductive system. They make male hormones and sperm. They are two egg-shaped glands inside the scrotum, a sac of loose skin that lies below the penis. You can get cancer in one or both testicles.
The full article covers:
- What is testicular cancer?
- Who is most likely to develop testicular cancer?
- What are the symptoms of testicular cancer?
- How is testicular cancer diagnosed?
- What are the treatments for testicular cancer?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert D40.10 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About D40.10Overview
Is D40.10 (Neoplasm of uncertain behavior of testis) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report neoplasm of uncertain behavior of unspecified testis on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does D40.10 group to?
When neoplasm of uncertain behavior of unspecified testis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 715, 716, 722, 723, 724, with relative weights from 0.6117 to 2.2373 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of D40.10?
Under the General Equivalence Mappings, neoplasm of uncertain behavior of unspecified testis converts to ICD-9-CM 236.4 (unc behav neo testis). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
