Neoplasm of uncertain behavior of meninges (D42) ICD-10-CM
The D42 code range covers neoplasm of uncertain behavior of meninges 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.
Codes in the D42 Range 4 codes · 3 billable
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the D42 range.
Arachnoid
A delicate membrane enveloping the brain and spinal cord. It lies between the PIA MATER and the DURA MATER. It is separated from the pia mater by the subarachnoid cavity which is filled with CEREBROSPINAL FLUID.
Arachnoid Cysts
Intracranial or spinal cavities containing a cerebrospinal-like fluid, the wall of which is composed of arachnoidal cells. They are most often developmental or related to trauma. Intracranial arachnoid cysts usually occur adjacent to arachnoidal cistern and may present with HYDROCEPHALUS; HEADACHE; SEIZURES; and focal neurologic signs. (From Joynt, Clinical Neurology, 1994, Ch44, pp105-115)
Arachnoiditis
Acute or chronic inflammation of the arachnoid membrane of the meninges most often involving the spinal cord or base of the brain. This term generally refers to a persistent inflammatory process characterized by thickening of the ARACHNOID membrane and dural adhesions. Associated conditions include prior surgery, infections, trauma, SUBARACHNOID HEMORRHAGE, and chemical irritation. Clinical features vary with the site of inflammation, but include cranial neuropathies, radiculopathies, and myelopathies. (From Joynt, Clinical Neurology, 1997, Ch48, p25)
Medulloblastoma
A malignant neoplasm that may be classified either as a glioma or as a primitive neuroectodermal tumor of childhood (see NEUROECTODERMAL TUMOR, PRIMITIVE). The tumor occurs most frequently in the first decade of life with the most typical location being the cerebellar vermis. Histologic features include a high degree of cellularity, frequent mitotic figures, and a tendency for the cells to organize into sheets or form rosettes. Medulloblastoma have a high propensity to spread throughout the craniospinal intradural axis. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2060-1)
Meninges
The three membranes that cover the BRAIN and the SPINAL CORD. They are the dura mater, the arachnoid, and the pia mater.
Meningocele
A congenital or acquired protrusion of the meninges, unaccompanied by neural tissue, through a bony defect in the skull or vertebral column.
Pia Mater
The innermost layer of the three meninges covering the brain and spinal cord. It is the fine vascular membrane that lies under the ARACHNOID and the DURA MATER.
About the D42 Code Range
The ICD-10 code D42 and its subcodes are used to classify neoplasms of uncertain behavior arising in the meninges, the protective membranes surrounding the brain and spinal cord. These codes are applied when a tumor's exact nature—whether benign or malignant—is not clearly established.
The ICD-10 code D42.0 specifically refers to neoplasms of uncertain behavior located in the cerebral meninges, sometimes called atypical meningiomas or intracranial meningiomas. Code D42.1 identifies tumors in the spinal meninges, including uncertain neoplasms of the spinal cord area. When the exact site or detailed nature of the meninges tumor is unspecified, D42.9 is appropriate; this can include solitary fibrous tumors or meningiomas of uncertain behavior. Using these codes helps healthcare providers and coders accurately document cases where meninges tumors cannot definitively be characterized, facilitating patient management and data reporting. Understanding the synonyms linked to each code, like "meningioma of uncertain behavior" or "solitary fibrous tumor," assists in selecting the correct ICD-10 code for uncertain meninges neoplasms.
Questions About This Page
How many billable codes are in the D42 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 D42 range classify?
The range classifies neoplasm of uncertain behavior of meninges. 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.
