Co-occurring scalp arteriovenous malformation and dural arteriovenous fistula with diploic vein involvement: illustrative case

Abstract

BACKGROUND

Scalp arteriovenous malformations (AVMs) with co-occurring dural arteriovenous fistulas (dAVFs) are a rare combination of vascular pathologies. The additional presence of diploic veins has not yet been documented in the literature. The authors present the first such case and its clinical management accompanied by a review of reported concomitant scalp AVMs and dAVFs in the literature.

OBSERVATIONS

A young woman presenting with a large scalp deformity, diplopia, visual decline, and recurrent epistaxis was found to have a co-occurring scalp AVM and dAVF with diploic vein involvement. Combined endovascular therapy and open resection permitted safe removal of the scalp AVM and obliteration of the dAVF. The patient was discharged on postoperative day 6 without complication.

LESSONS

A combined approach of endovascular therapy for local control, supplemented by surgical ligation and resection, can yield excellent outcomes in these instances.

https://thejns.org/doi/10.3171/CASE26533

Scalp arteriovenous malformations (AVMs) are vascular anomalies wherein the nidus is embedded within the scalp.¹ They are primarily congenital in etiology, although traumatic, iatrogenic, infectious, and familial causes have also been cited.^2–4 Most scalp AVMs (71%) are fed by one dominant feeding artery with the superficial temporal artery (STA) being the main supply to the lesion in 90% of those cases.⁵ Scalp AVMs are generally non–life-threatening but can present with hemorrhage, seizures secondary to vascular steal, or significant impairment when they form near vital structures such as the orbit.^6,7

Dural AVFs (dAVFs) are abnormal connections between dural arteries and venous sinuses and/or cortical veins.⁸ Dural AVFs typically arise along the dural leaflets covering the brain or spinal cord. Arterial supply from dAVFs primarily derives from the carotid or vertebral arteries. Dural AVFs are generally rare and most often present in individuals aged 50–60 years.⁹ The etiology is unclear, with proposed causes including traumatic head injury, infection, prior craniotomy, tumors, and dural venous sinus thrombosis.⁹ Although most dAVFs are asymptomatic, instances of venous congestion and hypertension, pulsatile tinnitus, intracranial hemorrhage or edema, and seizures have been reported.¹⁰

Although dAVFs and scalp AVMs are rare vascular lesions, they are often documented in isolation. However, literature documenting patients with co-occurring scalp AVM and dAVF is scarce. Furthermore, the co-occurrence of these two lesions with diploic vein involvement has not been previously recorded. Thus, we present the case of a young woman with a large scalp AVM and dAVF with diploic vein involvement, and we provide a review of the current literature on concomitant scalp AVMs and dAVFs.

Illustrative Case

History and Presentation

We report the case of a 23-year-old female who presented in the clinic with headaches, recurrent epistaxis, diplopia, visual decline, and a large right frontal scalp deformity. She had no significant past medical history aside from a prior head trauma during childhood.

Neuroimaging

Scalp AVM

CT angiography of the right frontal scalp lesion demonstrated a 2.5 × 4 × 8–cm (anteriorposterior × transverse × craniocaudal) soft tissue lesion with abnormal vessels (Figs. 1 and 2). The lesion was fed by branches of the external carotid artery (ECA), especially the STA. Additional arterial supply arose from branches of the ophthalmic artery, including the supraorbital and supratrochlear arteries. The mass extended inferiorly toward the right nasal bridge and superior nasal portion of the right orbit. Venous drainage was indicated to be primarily to the right temporal region. Large communicating vessels piercing through the right frontal bone were also apparent. Mass effect from venous engorgement in the right orbit caused right-sided proptosis and stretching of the right optic nerve, explaining the patient’s diplopia and visual decline.

FIG. 1.

Pre‑ and postoperative CT images and angiograms of the scalp AVM. A:Three‑dimensional CT angiography reconstructions demonstrating the scalp AVM (box) preoperatively (left) and its absence postoperatively (right). B: Sagittal CT images showing the scalp AVM (box) with associated calvarial hyperostosis (red arrow) and extension into the orbital cavity (yellow arrow) preoperatively (left), with resolution of the lesion postoperatively (right). C: Axial CT angiograms further depicting the scalp AVM and its relationship to the underlying calvarium (box; left).

FIG. 2.

Preembolization angiograms demonstrating the scalp AVM (box) and the dAVF (circle). A: Lateral view of a right ECA injection highlighting the right STA (arrows) and facial artery branches supplying the scalp AVM. B: Lateral venous‑phase view showing early drainage to the cavernous sinus via the right superior ophthalmic vein (white arrow), as well as to the SSS (black arrows) through the diploic-dAVF interface (circle). C: Lateral view of a right ICA injection demonstrating additional AVM supply from the right ophthalmic artery (arrows). D:Frontal view of a left ECA injection visualizing the left STA (arrows) extending to and supplying the scalp AVM.

Dural AVF

The main arterial supply to the dAVF arose from the right STA and right facial artery, with accessory supply from distal left STA branches. Venous drainage occurred through two principal pathways. First, arterialized flow entered engorged diploic veins of the right frontal region (Fig. 1) and then coursed inferiorly and to the right to exit the skull at the nasal aspect of the roof of the right orbit via enlarged emissary veins and the right superior ophthalmic vein before draining into an enlarged right cavernous sinus. Second, a portion of the shunt drained superiorly along dural channels into the anterior aspect of the superior sagittal sinus (SSS), which was enlarged relative to its posterior segment, most likely related to early fistulous drainage into this area. These findings confirm direct involvement of the frontal diploic venous compartment in the dAVF shunt, rather than transosseous venous communication from the scalp AVM alone.

Angiographically, drainage was predominantly through the right superior ophthalmic vein into the cavernous sinus, with comparatively less intense opacification of the anterior SSS and right transverse sinus, indicating secondary, lower‑flow outflow pathways (Fig. 2). No cortical venous reflux was identified, consistent with a low‑grade Borden type I/Cognard type I or IIa lesion.

Treatment

After extensive discussion, the patient elected to undergo a combined, staged approach. First, a targeted endovascular embolization of the arterial feeders to both the scalp AVM and dAVF was utilized to reduce flow through the shared STA and facial arteries prior to open resection and dAVF disconnection (Figs. 2 and 3). Obliteration of the right facial artery was achieved, reducing flow. Following embolization, surgical ligation was performed via bicoronal incision with a right frontal craniotomy to disconnect the large mass from the feeding arteries.

FIG. 3.

Postembolization angiograms. Lateral (A), frontal (B), and inferolateral oblique (C) projections demonstrating complete obliteration of the right facial artery (circle) with markedly reduced flow to the scalp AVM.

In the early phase of open resection, the main arterial feeders to the scalp AVM were severed, allowing for anterior reflection of the AVM. It was noted that the frontal bone, where the scalp AVM was located, was abnormally thick, consistent with radiographic findings. Additionally, there was a large emissary vein penetrating the frontal bone. The AVM was disconnected, and the remaining communicating vessels were targeted via orbitotomy. Extra precautions were taken to protect the globe. After removal of the scalp AVM and disconnection of the dAVF, the frontal sinus was cranialized and the anterior nasal sinus outflow tracts were obliterated to reduce the risk of future CSF leakage and infection.

Because of the extensive drilling, reconstruction was necessary. Reconstruction included dural repair with DuraSeal and placement of the pericranial flap over the exposed dura. The frontal bone defect was reconstructed with a KLS Martin neuroplating system, while harvested autologous bone chips were used to pack remaining bony defects before securing the bone flap. The patient tolerated the procedure well and was discharged home on postoperative day 6 without complication.

Follow-Up

The patient was seen in clinic 1 month postoperatively and was doing well, with complete resolution of the scalp AVM and no recurrent symptoms.

Informed Consent

The necessary informed consent was obtained in this study.

Case Summary and Key Points

We present the case of a 23-year-old woman with a scalp AVM and dAVF involving diploic veins. In our case, the patient had two main arterial feeders: the facial artery and STA. Diploic vein involvement in this case is also unusual and initially raised concern for sinus pericranii. However, the nidus was intradermal within the scalp and not firmly adherent to the calvaria, and venous filling was not gravity dependent, findings that argue against sinus pericranii and instead indicate a scalp AVM with concomitant dAVF shunting to the frontal diploic venous compartment. Arterial inflow and venous outflow pathways of the scalp AVM and associated dAVF are summarized schematically (Fig. 4). Despite the complexity of this case, the combined approach consisting of endovascular therapy, surgical ligation, and resection permitted safe and successful removal of the lesion and resolved the patient’s symptoms. Findings from our literature review also support this approach.

FIG. 4.

Schematic representations of arterial inflow (A) and venous outflow (B) pathways of the scalp AVM and associated dAVF. Panel A was created in BioRender. McGinley, C. (2026) https://BioRender.com/omyh1hh. Panel B was created in BioRender. McGinley, C. (2026) https://BioRender.com/wl8gx82.

Literature Review

We identified 11 eligible articles totaling 11 patients with a concomitant scalp AVM and dAVF (Table 1).^11–21 There were more males (n = 8) than females (n = 3), and the mean age was 19.09 ± 15.61 years. Three patients had reported trauma prior to the formation of their vascular lesions. Most patients (9/11, 81.8%) reported scalp lesions before age 18 years, suggesting a potential congenital predisposition to their development. No patients had a family history of arteriovenous anomalies. Four patients presented with additional vascular abnormalities (4/11, 36.4%) beyond their scalp AVM and dAVF. Almost all patients (9/11, 81.8%) reported an enlarging scalp mass as the primary symptom. Additional symptoms included headaches, visual disturbance, tinnitus, altered consciousness, and vertigo. Most lesions were left-sided and most often involved the SSS. Lastly, equal numbers of patients received endovascular therapy alone (n = 3) or resection alone (n = 3).

TABLE 1.

Literature review results of concomitant scalp AVM and dAVFs

Authors & Year	Sex	Age (yrs)	Diagnosis	Symptoms	Feeding Supply	Draining Supply	Sinus Involvement	Location of Scalp AVM	Intervention	Outcome	Notes
Ibraheem et al., 202421	F	18	Scalp AVM, dAVF	Enlarging scalp mass	Bilat OcA, bilat STA	NA	SSS	Lt parieto-occipital scalp	Resection alone	Uncomplicated recovery	No hx trauma; type IIIa AVM, Yakes classification of AVMs
Kaul et al., 202320	F	51	Scalp AVM, sinus pericranii, SM grade V bAVM, Cognard type I dAVF	Enlarging scalp mass, recurrent bleeding from lesion	Rt STA	Superficial facial veins	SSS	Rt frontal scalp	Endov ascular treatment alone → embolization (transarterial & transvenous) alone	Embolization complicated by iatrogenic stroke producing lt-sided hemiparesis & homonymous hemianopia; DSA was beneficial at first but then led to multiple collateral formations	SM grade V bAVM was receiving supply from rt MCA and rt PCA w/ venous drainage to superficial sylvian vein to transverse-sigmoid junction w/ Trolard vein involvement from the SSS; prior hx trauma; AVM noted at childhood
Shao & Cao, 202419	M	37	Scalp AVM, dAVF	Headaches, blurred vision, tinnitus	Bilat ECA, OcA, & STA	Vein of Labbé, Trolard vein	Lt transverse sinus, lt sigmoid sinus, SSS	Anterior, lateral, posterior, & occipital scalp	None	NA	No significant family hx surgeries; prior hx trauma
Brinjikji et al., 202018	M	26	Scalp AVM, dAVF	Enlarging scalp mass	Posterior meningeal artery, then meningohypophyseal trunks, bilat OcA, posterior divisions of MMA bilaterally, & bilat PCAs	NA	Torcula, then torcula & lt transverse sinus	Lt parietal scalp	Embolization → repeated embolization	Embolizations did not sufficiently obliterate the dAVF, resulting in multiple embolization attempts that were unsuccessful	Pt had progressive development of AVF & cavernous malformation from time of treatment
Ung et al., 202017	M	15	Scalp AVM, dAVF	Enlarging scalp mass, tinnitus, headache, phonophobia, photophobia, vertigo	Lt STA, lt posterior auricular artery, lt OcA, lt OpA	NA	Lt sigmoid sinus, lt transverse sinus	Lt temporal to parieto-occipital scalp	Embolization +resection	Uncomplicated recovery & complete resolution of symptoms	No family hx AVM or other vascular malformations; Cognard type I dAVF; AVM noted since birth
Kanth et al., 201916	M	5	Scalp AVM, dAVF	Enlarging scalp mass, pain & discomfort at lesion	NA	Emissary veins	Lt sigmoid sinus	Lt occipital scalp	Resection alone → re-resection	Initial resection was complicated by swelling at index site 5 mos postop; re-resection permitted complete resolution of symptoms & no recurrence	AVM noted since birth
Li et al., 201815	M	14	Scalp AVM, dAVF	Enlarging scalp mass	Bilat STA, bilat branches of distal OpA (supratrochlear & supraorbital)	Emissary veins	SSS	Forehead	Embolization +resection	Uncomplicated recovery & complete resolution of symptoms	No hx trauma, febrile illness, or family hx vascular malformations
Chen et al., 201114	M	31	Scalp AVM, anterior cranial fossa dAVF	Enlarging scalp mass	Lt anterior ethmoidal artery, bilat STA, supraorbital branches of OpA	Cortical veins	SSS	Lt forehead	None	NA	dAVFs of anterior cranial fossa are exceedingly rare but have a high incidence of intracranial hemorrhage
Massimi et al., 200913	M	2	Scalp AVM, dAVF, SM grade III bAVM, sigmoid sinus atresia	Enlarging scalp mass	Temporal branches of lt PCA	Emissary veins	SSS, transverse sinus	Lt temporomesial scalp	Embolization alone	Uncomplicated recovery	Prior hx trauma
Lanzino et al., 200312	M	4	Scalp AVM, dAVF, intraparenchymal bAVM	Enlarging scalp mass	Posterior STA & OcA	Emissary veins	SSS	Parietal scalp	Resection +SRS	Uncomplicated recovery	No hx trauma
Mizutani et al., 199211	F	7	Multiple AVMs involving cerebrum & extra-axial posterior fossa, calcified cyst, spinal cord, dural, & scalp AVMs, port-wine stain	Sudden onset altered consciousness, visible port-wine stain w/ scalp AVM	Rt ECA, rt MMA	Superficial temporal veins	NA	Rt temporoparietal scalp	Resection alone → re-resection	Complicated by development of bilat motor ataxia & deep sensation in the rt extremities, recovery w/in 6 mos	No sinus involvement indicated

bAVM = brain AVM; DSA = digital subtraction angiography; Hx = history of; MMA = middle meningeal artery; NA = not applicable; OcA = occipital artery; OpA = ophthalmic artery; PCA = posterior cerebral artery; SM = Spetzler-Martin.

Observations

Literature Review Findings

There was considerable variation in the verbiage used throughout the literature, potentially due to the paucity of cases and a lack of consensus on nomenclature. Some authors referred to scalp AVMs as “scalp arteriovenous fistulas or malformations,” “cirsoid aneurysms,” “scalp arteriovenous fistulas without intracranial extension,” “aneurysma serpentinum,” or “plexiform angioma.”⁶ The nomenclature for concomitant scalp AVMs and dAVFs also showed significant variation. Some reports even cited them as a single entity: “scalp arteriovenous fistula with intracranial extension to sinuses.” Our group identifies these as two separate lesions (scalp AVMs and dAVFs). Dural AVFs are distinguished from AVMs by their arterial supply arising from vessels that perfuse the dura mater. Notwithstanding, dAVFs lack a parenchymal nidus, as seen in traditional AVMs.²²

Particular care was taken to distinguish between sinus pericranii and scalp AVMs with concurrent dAVF, as treatment options for these entities can differ substantially. Sinus pericranii can closely mimic scalp AVMs, presenting as an enlarging, compressible scalp mass with headache, vertigo, or nausea.

However, there are several characteristics that are unique to the two pathologies. Sinus pericranii is a collection of thin-walled venous channels that are tightly adherent to the cranium. Filling of the mass in sinus pericranii is gravity dependent and exacerbated by increased intracranial pressure.²³ Sinus pericranii also involves transosseous communications with the sinuses, frequently to the SSS.²⁴ This differs from scalp AVMs, which are typically confined to the scalp and whose feeding and draining vessels arise from scalp vessels.

As for treatment, sinus pericranii is subclassified as either dominant (if the majority of the venous flow communicates through the lesion while bypassing typical venous outlets) or accessory (if only a portion of the intracranial venous flow communicates through the lesion).²⁵ Surgery or endovascular treatment may be indicated for accessory sinus pericranii to ameliorate symptoms, prevent future traumatic bleeding and air embolism, or for cosmetic reasons.^26,27 Alternatively, nonconservative treatment (i.e., surgery or endovascular) for dominant sinus pericranii is contraindicated because disconnection of the major venous outflow could result in severe brain swelling.²⁶

Lessons

Scalp AVM Treatment Considerations

When approaching any AVM, total resection of the nidus is critical as incomplete resection is correlated with increased recurrence. This fact was highlighted in a study conducted by Goldenberg et al., which demonstrated a regrowth rate of 18.2% in cases with total resection of AVMs, compared with a rate of 66.7% when partial resection was performed.²⁸ Other studies have shown that AVMs often recur over time, especially extracranial AVMs, but open surgery, with or without embolization, results in lower recurrence rates and a longer time to recurrence.²⁹

The way nidus resection is achieved for extracranial AVMs, like scalp AVMs, vastly differs from that for intracranial AVMs. Extracranial AVMs, including scalp AVMs, are commonly staged using the Schobinger staging system,³⁰ which guides treatment strategy and aggressiveness. The Schobinger system classifies lesions based on clinical progression from quiescent stage I to stage IV lesions with pain, ulceration, and high‑output cardiac failure. Stage I lesions, even when extensive, are typically managed conservatively with close follow-up and compression stockings, as aggressive intervention could worsen clinical status and recurrence is likely.³¹ Interventional therapy for AVMs, like surgery, is often reserved for progressive lesions of Schobinger stage II AVMs and above.³²

Open surgery, either as an adjunct to endovascular treatment or alone, warrants significant consideration. The main limitations for aggressive intervention for these stages are generally limited to soft tissue loss, cosmetic and functional morbidity, and recurrence. Thus, treatment can be more aggressive toward achieving total nidus resection. Open surgery often yields a favorable response, particularly when the lesions are small and well localized. The major contraindication for aggressive resection is diffuse AVMs, as they tend to fare worse in surgical intervention alone.³¹

Intracranial AVMs carry greater risk for surgical morbidity and mortality and are typically assessed with the Spetzler-Martin grading system, which incorporates nidus size, eloquence of adjacent brain tissue, and venous drainage to estimate surgical risk and morbidity.³³ In our case, the scalp AVM is best described using the Schobinger criteria, rather than Spetzler-Martin grading.

Dural AVF Treatment Considerations

Dural AVFs are classified via the Cognard or Borden system.^34,35 Both systems use a method to evaluate the venous draining pattern and associated hemorrhage risk and degree of subsequent neurological decline. Ultimately, both systems aim to delineate between a benign and malignant dAVF through the presence of venous cortical drainage. This cortical drainage can increase the amount of venous flow through the brain’s cortical veins and cause increased arterial pressure. This, in turn, can result in increased hemorrhage risk and neurological deficits.

Generally, low-grade lesions (i.e., those without cortical venous drainage) correspond to Borden type I and Cognard types I and IIa. They are usually asymptomatic or minimally symptomatic with minimal annual hemorrhage risk and negligible mortality. For higher-grade dAVFs (Borden types II and III and Cognard types IIb–IV), intervention is often needed. Endovascular therapy is often first line of treatment for dAVFs, with the goal to obliterate fistulous points or disconnect cortical venous drainage. Our patient’s dAVF demonstrated venous drainage into dural sinuses (cavernous, anterior superior sagittal, and right transverse) without cortical venous reflux, consistent with a low‑grade Borden type I/Cognard type I or IIa lesion, for which combined endovascular and surgical therapy is appropriate when symptoms and lesion complexity warrant intervention.

Open surgery may also be amenable to dAVF treatment. Dural AVFs that arise in the anterior cranial fossa and ethmoid region often fare exceptionally well from open surgery.³⁶ Open surgery in these regions is managed more safely than endovascular therapy during surgical disconnection of venous drainage.³⁶ Additionally, in instances in which the dAVF is inaccessible transvascularly, surgery can permit better accessibility. Other demonstrations of the utility of open surgery on dAVF management have been seen in cases with cavernous sinus involvement, symptomatic dAVFs with hemorrhage or severe symptoms like seizures or paresis, or cases with residual or partially treated fistulas.³⁷

Endovascular therapy alone is less effective than open surgery as a stand-alone treatment. First, there are potential complications inherent to embolization, such as embolic obstruction of nontargeted arteries, inflammation of local and perivascular tissues, and soft tissue tattooing.³² Second, endovascular therapy alone is associated with a higher recurrence rate of dAVF formation. In an extensive retrospective review of the Consortium for Dural Arteriovenous Fistula Outcomes Research data, Abecassis et al. found that 32 of 457 patients (7%) had recurrence of dAVF formation.³⁹ More importantly, all patients in this study (32/32, 100%) who had recurrence of their dAVF underwent endovascular therapy alone. However, none of the patients who underwent surgical intervention, with or without adjunctive endovascular treatment, had recurrence.^38,39 This finding was also consistent in our literature review results, which showed that patients who underwent endovascular therapy alone had also undergone serial endovascular procedures without resolution.^18,20 These results further attest to the utility of a combined approach, or at least warrant the consideration of open surgery, when managing these cases.

Stereotactic radiosurgery (SRS) can serve as an adjuvant therapy for selected dAVFs with cortical venous drainage and low hemorrhage risk, particularly those with persistent flow after surgery or embolization.^40,41 In addition to its safe therapeutic profile, successful obliteration rates are around 50%–70%, with most patients experiencing clinical improvement.^40–42 However, its latency period and limited efficacy in lesions with high hemorrhage risk or persistent pial venous drainage restrict its use to carefully selected dAVFs.⁴⁰

Combined Approach

In our patient, we used a dual approach for treatment: embolization followed by ligation and resection of the scalp AVM. Our review of the literature further supports this approach as 2 patients had also undergone this dual approach and had an uncomplicated course and successful recovery.^15,17 Endovascular therapy is generally considered a first-line option for many dAVFs and scalp AVMs. This can include particulate embolization, liquid embolic agents, coil embolization, or venous stenting. The utilization of endovascular embolization enabled reduced flow through the lesions, thus reducing hemorrhage risk.

Embolization has been well documented to aid in achieving total resection, especially when combined with surgery. Embolization also significantly reduces the risk of intraoperative bleeding.²⁸ Considerations like these are pertinent in our case, as our patient had diffuse scalp involvement with multiple arterial feeders. Scalp AVMs with diffuse scalp involvement that contain multiple arterial feeders are documented to be much more challenging to treat, have higher recurrence rates after treatment, and are also associated with a higher risk of surgical morbidity.⁴³

When considering a dual approach, given the potential side effects of treatment, tailoring the treatment to the patient is crucial. However, with the co-occurrence of dAVFs, there may be consideration for more aggressive treatment even in instances of Schobinger stage I lesions. In combined embolization and surgery, resection within 24–48 hours of embolization is ideal to prevent acute inflammation caused by embolic materials.⁴³

Insight and Causes

The pathogenesis of concomitant scalp AVMs and dAVFs is not well defined, although several theories have been proposed. Whether the dAVF arose from the scalp AVM, vice versa, or independently is unclear. Experimental work from Terada et al. demonstrated that venous hypertension alone could cause new AVFs and soft tissue AVMs in rat models, suggesting that hemodynamic factors may contribute to lesion formation in the absence of thrombosis.⁴⁴ This theory also coincides with the findings of Lanzino et al., in which venous hypertension alone without thrombosis can cause vascular anomalies.¹² Genetic models of hereditary hemorrhagic telangiectasia suggest a “second-hit” paradigm where germline mutations in endogelin or activin receptor-like kinase genes affect local angiogenic stimuli to produce AVMs.^45,46 Syndromes like Osler-Weber-Rendu, Sturge-Weber, and Wyburn-Mason syndromes have received considerable attention because of their propensity to form multiple vascular lesions, but their role has not been identified.^11,20

The presence of diploic venous involvement in our patient suggests that transosseous venous pathways may serve as intermediate conduits for venous hypertension and shunt formation, linking extracranial scalp AVMs to intracranial dAVFs in select cases. Clinically, recognizing diploic vein participation may prompt earlier and more aggressive combined management in symptomatic patients, as these transosseous channels can transmit hemodynamic stress from a scalp AVM nidus to intracranial venous sinuses and dAVF shunts, potentially worsening orbital congestion or intracranial venous hypertension.

In conclusion, we report the first case of a young woman with concomitant scalp AVM and dAVF with diploic vein involvement, together with a review of the current literature and insights into this condition. As this is a case report, generalizability is limited and further work is needed to clarify nomenclature and outcomes for these patients.

Acknowledgments

Perplexity (GPT-5.1 large language model–based assistant) and Grammarly were used to improve clarity, language, and organization of the manuscript text. BioRender’s Academic Plan possesses generative figure tools and was used for initial template and schematic figure creation. We performed and verified final revisions.

Disclosures

The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

Author Contributions

Conception and design: Abla, McGinley, Wu. Acquisition of data: Abla, McGinley, Wu. Analysis and interpretation of data: all authors. Drafting the article: Abla, McGinley, Wu. Critically revising the article: all authors. Reviewed submitted version of manuscript: Abla, McGinley. Approved the final version of the manuscript on behalf of all authors: Abla. Statistical analysis: McGinley. Administrative/technical/material support: Abla, McGinley. Study supervision: all authors.

Correspondence

Adib Abla: University of Miami Miller School of Medicine, Miami, FL. adib.abla@miami.edu.