statdx/docs_md/articles/cyst-with-nodule_6cb71737-f574-4121-a8fb-02eeada9f9f7.md

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Cyst With Nodule	6cb71737-f574-4121-a8fb-02eeada9f9f7	key value 4b6589b0-9b8d-4467-8a90-01a0a59742fc Troy A. Hutchins, MD key value 8d5254e9-8dda-478b-8f08-bdee97a32c79 Karen L. Salzman, MD, FACR	name slug treeNodeId Brain brain 6d8829f1-14d7-45af-8675-255189aa526a name slug treeNodeId Differential Diagnosis differential-diagnosis a7fdd139-664e-4bb8-8d18-400e4733ff60 name slug treeNodeId Brain Parenchyma, General brain-parenchyma-general e79be97b-28c0-4023-be87-334c0579d35d name slug treeNodeId Generic Imaging Patterns generic-imaging-patterns 66ab9cf6-74ad-42b7-a40a-4b6224edaa25 name slug treeNodeId Cyst With Nodule cyst-with-nodule null	Brain	a8a6b610-83a2-461f-bc34-b34af327c00c	35	03/14/23	Cyst With Nodule	Brain, Differential Diagnosis, Brain Parenchyma, General, Generic Imaging Patterns, Cyst With Nodule	Cyst With Nodule | STATdx	Cyst With Nodule	DDX	true	Brain Differential Diagnosis Brain Parenchyma, General Generic Imaging Patterns Cyst With Nodule

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title: "Cyst With Nodule" docid: "6cb71737-f574-4121-a8fb-02eeada9f9f7" authors:

• key: "4b6589b0-9b8d-4467-8a90-01a0a59742fc" value: "Troy A. Hutchins, MD"
• key: "8d5254e9-8dda-478b-8f08-bdee97a32c79" value: "Karen L. Salzman, MD, FACR" breadcrumbs:
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• name: "Generic Imaging Patterns" slug: "generic-imaging-patterns" treeNodeId: "66ab9cf6-74ad-42b7-a40a-4b6224edaa25"
• name: "Cyst With Nodule" slug: "cyst-with-nodule" treeNodeId: null category: "Brain" documentVersionId: "a8a6b610-83a2-461f-bc34-b34af327c00c" imageCount: 35 lastUpdated: "03/14/23" pageDescription: "Cyst With Nodule" pageKeywords: "Brain, Differential Diagnosis, Brain Parenchyma, General, Generic Imaging Patterns, Cyst With Nodule" pageTitle: "Cyst With Nodule | STATdx" enhancedTitle: "Cyst With Nodule" type: "DDX" references: true breadcrumbs:
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• "Differential Diagnosis"
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• "Cyst With Nodule"

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ESSENTIAL INFORMATION

• Key Differential Diagnosis Issues

  • Cystic lesions with solid nodular components can be divided into 2 categories - Lesions that typically demonstrate cyst with nodule morphology - Neurocysticercosis (NCC), pilocytic astrocytoma, ganglioglioma, hemangioblastoma, pleomorphic xanthoastrocytoma (PXA), desmoplastic infantile ganglioglioma (DIG), intraparenchymal schwannoma - Lesions that may demonstrate cyst with nodule morphology - Metastases, glioblastoma (GBM), abscess, toxoplasmosis, parasites, dysplastic neuroepithelial tumor (DNET), thrombosed arteriovenous malformation (AVM), supratentorial ependymoma
  • Although metastases, abscesses, & GBMs do not classically present as "cysts with nodules," they are included because of their overall prevalence - Statistically, atypical form of these common diseases may be more likely than some of other "classic" cysts with nodule lesions

• Helpful Clues for Common Diagnoses

  • Neurocysticercosis - Intracranial parasitic infection caused by pork tapeworm Taenia solium - Cyst with "dot" inside representing scolex - Imaging appearance varies with stage; increased enhancement & edema when organism dies (inflammatory host response) - Location: Convexity subarachnoid space > > cisterns > parenchyma > ventricles - Lesions may be at different stages in same patient
  • Pilocytic Astrocytoma - Cerebellar cystic mass with mural nodule in child; rarely supratentorial - T1 C+ MR: Nodule shows intense but heterogeneous enhancement - Cyst wall may show enhancement - T1 & T2 MR: Cyst content iso- to hyperintense to CSF - Most common brain tumor in children
  • Ganglioglioma - Cortically based, slow-growing, enhancing mass in older child or young adult - Circumscribed cyst with mural nodule most common - May be solid and appear well circumscribed - Often expands cortex; calcification common - Most common tumor to cause temporal lobe epilepsy - Cortical dysplasia is commonly associated
  • Hemangioblastoma - Vascular neoplasm of uncertain etiology - Parenchymal posterior fossa cyst with nodule mass in adult - T1 C+ MR: Nodule abuts pial surface & shows intense, homogeneous enhancement - Prominent flow voids may be seen - Multiple in von Hippel-Lindau syndrome (VHL) (25-40% of hemangioblastomas)

• Helpful Clues for Less Common Diagnoses

  • Metastases, Parenchymal - Discrete, gray-white interface mass(es) with adjacent vasogenic edema - Multiplicity, history of primary malignancy helpful if present - Solitary metastasis may mimic GBM - Often known history of primary neoplasm
  • Glioblastoma, IDH-Wildtype - Malignant white matter mass with central necrosis - Predilection to spread across midline along corpus callosum; "butterfly glioma" - T1 C+ MR: Thick, irregular, nodular, enhancing margins - T2/FLAIR MR: Surrounding hyperintensity & mass effect reflect edema + infiltrative tumor
  • Pleomorphic Xanthoastrocytoma - Cortically based cyst + nodule ± involvement of adjacent meninges - T1 C+ MR - Enhancing nodule - Thickening, enhancement of adjacent meninges - 70% have dural tail - Temporal lobe predominance; young adult - Maybe associated with cortical dysplasia
  • Abscess - T2 MR: Hypointense rim with surrounding edema classic - T1 C+ MR: Enhancing capsule thinnest at ventricular side - DWI MR: Cystic component bright (diffusion restriction) - SWI MR: Dual rim sign (hypointense outside, hyperintense inside )
  • Opportunistic Infection, AIDS, Toxoplasmosis - Caused by parasite Toxoplasma gondii - Toxoplasmosis: Ring-enhancing lesion containing eccentric nodule = eccentric target sign specific but not sensitive - Location: Basal ganglia > hemispheres - Clinical: Immunocompromised patient
  • Parasites, Miscellaneous - Multiple enhancing lesions typical - May mimic brain tumor - Travel history critical
  • Dysplastic Neuroepithelial Tumor - Bubbly, wedge-shaped, cortically based mass "points" toward lateral ventricle - T2 MR: Very hyperintense; nodular, septate; no surrounding edema - FLAIR MR: Hyperintense ring sign - Thin rim of well-defined peritumoral hyperintensity separating it from surrounding normal brain - T1 C+ MR: No to minimal enhancement; may be nodular - Temporal lobe predominance

• Helpful Clues for Rare Diagnoses

  • Desmoplastic Infantile Ganglioglioma - Supratentorial cystic/nodular mass with dominance of cyst - Cortically based nodule with intense enhancement & dural tail - May be massive - Peak age: 3-6 months
  • Schwannoma, Intraparenchymal - Only 1-2% of schwannomas are parenchymal - Cyst with strongly enhancing nodule
  • Arteriovenous Malformation - When hemorrhagic with partial or complete thrombosis, may present as cyst with nodule - Blood breakdown products of various ages; fluid-fluid levels
  • Ependymoma, Supratentorial - 40% of supratentorial ependymomas are extraventricular - Large, complex, mixed solid/cystic mass - Calcification, intratumoral hemorrhage common - Moderate but inhomogeneous enhancement
  • Meningioma (Cystic) - Meningioma with intraparenchymal cyst may mimic cyst + nodule mass
  • Rosette-Forming Glioneuronal Tumor - Rare, slowly growing benign tumor of young adults - 4th ventricle most common site > cerebellum - Mixed solid-cystic appearance, variable Ca⁺⁺, hemorrhage - May show cyst with nodule configuration
  • Papillary Glioneuronal Tumor - Temporal lobe predilection - Parenchymal mass with solid, cystic, or cyst/mural nodule architecture - May show calcification - Imaging may be indistinguishable from ganglioglioma

• Alternative Differential Approaches

  • By location - Posterior fossa: Pilocytic astrocytoma, hemangioblastoma, metastasis, Rosette-forming glioneuronal tumor - Temporal lobe: Ganglioglioma, PXA, DNET, papillary glioneuronal tumor - Gray-white junction: Metastases, abscess - Hemispheric: NCC, metastases, GBM, infections, DIG, AVM, supratentorial ependymoma
  • Patient age - Child & young adult: Pilocytic astrocytoma, ganglioglioma, PXA, DNET - Adult: Hemangioblastoma, GBM, metastases - Any age: NCC, abscess, other infections
  • Multiple lesions - Metastases (50-55%), NCC (50-70%), hemangioblastoma (VHL), abscesses (septic emboli), toxoplasmosis, parasites

References

Selected References

1. Sotoudeh H et al: Radiomics for differentiation of the posterior fossa pilocytic astrocytoma versus hemangioblastomas in adults. A pilot study. Clin Imaging. 93:26-30, 2022
2. Medhi G et al: Imaging features of rosette-forming glioneuronal tumours (RGNTs): a series of seven cases. Eur Radiol. 26(1):262-70, 2016
3. Carangelo B et al: Papillary glioneuronal tumor: case report and review of literature. G Chir. 36(2):63-9, 2015
4. Raz E et al: Cyst with a mural nodule tumor of the brain. Cancer Imaging. 12:237-44, 2012
5. Kumar GG et al: Eccentric target sign in cerebral toxoplasmosis: neuropathological correlate to the imaging feature. J Magn Reson Imaging. 31(6):1469-72, 2010
6. Smirniotopoulos JG et al: Patterns of contrast enhancement in the brain and meninges. Radiographics. Mar-Apr;27(2):525-51, 2007

Images

Selected Images

Neurocysticercosis Axial FLAIR MR demonstrates a neurocysticercosis cyst with an eccentric nodule (scolex) . Additional lesions have surrounding edema . Edema and enhancement vary with the stage of neurocysticercosis and host response.

Neurocysticercosis Axial FLAIR MR demonstrates a neurocysticercosis cyst with an eccentric nodule (scolex) . Additional lesions have surrounding edema . Edema and enhancement vary with the stage of neurocysticercosis and host response.

Pilocytic Astrocytoma Axial T1 C+ SPGR MR shows a pilocytic astrocytoma with enhancing, eccentric nodule . There is cyst wall enhancement (present in ~ 50% of cases). Note obstructive hydrocephalus with dilation of superior 4th ventricle secondary to mass effect.

Ganglioglioma Coronal T1 C+ MR in a young adult patient with epilepsy shows a cystic and solid mass in the temporal lobe with intense enhancement of the solid mural nodule . Gangliogliomas are the most common tumor to cause temporal lobe epilepsy.

Hemangioblastoma Coronal T1 C+ MR in an adult patient reveals a cystic mass with an intensely enhancing mural nodule in the posterior fossa. Additional enhancing nodules are noted in this patient with von Hippel-Lindau.

Metastases, Parenchymal Coronal T1 C+ MR in a patient with primary malignancy demonstrates a cystic and solid, enhancing, nodular mass with the surrounding vasogenic edema . Multiple additional lesions and clinical history can help with diagnosis.

Glioblastoma, IDH-Wildtype Axial T1 C+ FS MR shows an infiltrative left frontal lobe glioblastoma with cystic and heterogeneously enhancing, solid, nodular components. Glioblastomas have a predilection for crossing midline through the corpus callosum.

Pleomorphic Xanthoastrocytoma Coronal T1 C+ MR shows a cortically based left temporal lobe cystic mass with an enhancing nodule in a young adult. Enhancement & thickening of the adjacent dura help diagnose PXA & differentiate from a ganglioglioma.

Abscess Sagittal T1 C+ MR in a patient treated for sinusitis who presented with headache, fever, and seizures shows a large, ring-enhancing abscess with an eccentric nodule . DWI (not shown) showed characteristic diffusion restriction in the central nonenhancing component.

Opportunistic Infection, AIDS, Toxoplasmosis Axial T1 C+ FS MR in an immunocompromised patient shows a ring-enhancing lesion with peripheral enhancing nodule . This eccentric target sign is specific but not sensitive for toxoplasmosis. Note the numerous additional nodular and ring-enhancing lesions and surrounding edema .

Parasites, Miscellaneous Axial CECT demonstrates a ring-enhancing lesion with an associated nodule and surrounding vasogenic edema. Multiple punctate lesions are also apparent in this patient with amebic encephalitis.

Dysplastic Neuroepithelial Tumor Axial T1 C+ MR in a patient with epilepsy shows a cortically based, bubbly, cystic mass with an eccentric, enhancing nodule . Faint, nodular enhancement can be seen in 20% of DNETs. FLAIR images often show a well-defined, hyperintense ring surrounding the mass.

Desmoplastic Infantile Ganglioglioma Coronal T1 C+ MR shows a large cyst with a cortically based, intensely enhancing mural nodule in an infant. Note the adjacent dural thickening & enhancement , typical of desmoplastic infantile ganglioglioma.

Schwannoma, Intraparenchymal Axial T1 C+ MR shows a cystic parenchymal mass with an intensely enhancing mural nodule in the right occipital lobe. Although ganglioglioma was the preoperative diagnosis, schwannoma was found on pathology.

Ependymoma, Supratentorial Axial T2 MR shows a recurrent supratentorial ependymoma with a cyst and nodule architecture. 40% of supratentorial ependymomas are extraventricular. They are commonly associated with calcification and hemorrhage.

Additional Images

Neurocysticercosis Axial FLAIR MR demonstrates a classic neurocysticercosis cyst with an eccentric nodule (scolex) in the right parietal lobe with surrounding vasogenic edema. The enhancement and edema varies with the stage of neurocysticercosis and host response.

Neurocysticercosis Axial T1WI MR shows a frontal & left lateral ventricular "cyst with dot." The "dot" or scolex may be T1 hyperintense . Edema & enhancement vary with stage & host response.

Pilocytic Astrocytoma Axial T1 C+ MR shows a classic cerebellar pilocytic astrocytoma. There is well-defined enhancement of the cyst wall with an enhancing eccentric nodule . Note the mass effect on the 4th ventricle with obstructive hydrocephalus.

Pilocytic Astrocytoma Axial T1 C+ MR shows a cystic mass with an intense, heterogeneously enhancing mural nodule in the posterior fossa of a child. Note associated temporal horn dilatation related to the tumor.

Ganglioglioma Coronal T1 C+ MR in a child with epilepsy demonstrates a cystic and solid mass in the temporal lobe with intense enhancement of the solid mural nodule . Gangliogliomas commonly cause temporal lobe epilepsy.

Ganglioglioma Coronal T1 C+ MR shows a circumscribed, cystic and solid mass in the temporal lobe with intense enhancement of the solid mural nodule . Note cortical location and lack of significant mass effect and edema. Gangliogliomas commonly cause temporal lobe epilepsy.

Hemangioblastoma Axial CECT in a middle-aged woman shows a cystic mass with an intensely enhancing mural nodule in the posterior fossa. Note extensive perilesional edema with mass effect and obstructive hydrocephalus. Histopathology revealed a hemangioblastoma.

Hemangioblastoma Sagittal T1 C+ MR shows a cystic mass with an intensely and homogeneously enhancing mural nodule in the posterior fossa of an adult. The nodule typically abuts the pial surface.

Metastases, Parenchymal Axial T1 C+ MR in a patient with breast carcinoma shows multiple metastatic lesions in the posterior fossa with a few showing a cyst and nodule morphology.

Metastases, Parenchymal Coronal T1 C+ MR shows a cystic mass with a large, enhancing nodule in the cerebellar hemisphere with rim enhancement . This is an atypical appearance for a metastasis. History of primary malignancy & presence of other lesions are helpful for diagnosis.

Metastases, Parenchymal Axial T1 C+ FS MR shows a "cystic" mass with nodular enhancement in this patient with colon cancer. Multiple lesions and clinical history are helpful for diagnosis.

Metastases, Parenchymal Coronal T1 C+ MR shows an irregularly enhancing perisylvian cystic & solid mass in this patient with multiple lesions related to metastatic disease. Note the surrounding vasogenic edema in the frontal lobe.

Glioblastoma, IDH-Wildtype Coronal T1 C+ MR shows a large, cystic mass with rim enhancement and an intensely enhancing, eccentric nodule . Note the mass effect with mild subfalcine herniation. Glioblastoma was the final pathology in this case.

Glioblastoma, IDH-Wildtype Axial CECT shows a heterogeneous mass with irregular peripheral enhancement containing a nodular component . Aggressive features help diagnose this malignant tumor.

Abscess Axial T1 C+ FS MR demonstrates a ring-enhancing lesion with a small, enhancing mural nodule . DWI MR (not shown) showed characteristic diffusion restriction in the central nonenhancing component.

Opportunistic Infection, AIDS, Toxoplasmosis Sagittal T1 C+ MR in an HIV-positive patient shows a ring-enhancing lesion in the parietal lobe with marked perilesional edema. Note the target appearance with central nodule , typical of toxoplasmosis.

Opportunistic Infection, AIDS, Toxoplasmosis Coronal T1 C+ MR shows basal ganglia, thalamic, & parenchymal ring-enhancing lesions in an immunocompromised patient. Note the target appearance with a central nodule in the right temporal lobe lesion.

Dysplastic Neuroepithelial Tumor Axial T2WI MR shows a wedge-shaped, extremely hyperintense, cortically based, bubbly mass that "points" toward the lateral ventricle. Faint nodular enhancement can be seen in 20% of cases.

Dysplastic Neuroepithelial Tumor Axial T1 C+ MR shows a left temporal lobe mass with a small focus of mild enhancement within the bubbly, cystic mass. Faint nodular enhancement can be seen in 20% of DNETs. Lesions are typically T2 hyperintense & may erode the adjacent calvarium, as in this case.

Ependymoma, Supratentorial Axial T2 MR shows a recurrent supratentorial ependymoma with a cyst and nodule architecture. NECT showed calcifications with the solid component. Note the old parietal craniotomy.

Arteriovenous Malformation Axial CECT shows a mixed-density, cystic and solid lesion with rim enhancement . There is a fluid-fluid level within 1 of the cysts , representing hemorrhage in this partially thrombosed arteriovenous malformation.