Pyogenic granuloma gravidarum: a case in the nasal cavity and the use of MRI as a preoperative surgical aide

Abstract

Pyogenic granuloma gravidarum is a benign fibrovascular proliferative lesion usually involving the oral gingivae in pregnant patients. While it also occurs, although less frequently, on other oral sites such as lips, tongue and palate, it is relatively unusual to find it in the nasal cavity. Furthermore, lesions normally involute spontaneously after childbirth. For persistent lesions requiring surgical management, imaging has historically been limited to CT. This case is notable not only for its uncommon location but also for its recurrent nature, failure to regress post partum and the use of MRI in the preoperative planning.

Background

Pyogenic granuloma gravidarum (PGG) is a benign fibrovascular proliferative lesion occurring in less than 5% of pregnant patients.¹ This case demonstrates a rare presentation of this condition and an alternative preoperative approach to planning using MRI as a surgical aide.

Most commonly involving the oral gingiva of pregnant patients, PGG also occurs, although less frequently, on other oral sites such as lips, tongue and palate. It is a relatively unusual finding in the nasal cavity.^{2 3} Furthermore, regardless of location, these lesions normally involute spontaneously after childbirth.⁴ Surgical management is advised for persistent lesions and imaging for this has historically been limited to CT.

This case is notable not only for its uncommon location but also for its recurrent nature, failure to regress post partum and its use of MRI in the preoperative planning.

Case presentation

A 35-year-old woman presented to an otolaryngology outpatient clinic at 4 weeks post partum with a 3-month history of right-sided epistaxis. She reported a similar presentation following her previous pregnancy 3 years earlier, when a mass in the right nasal cavity was removed and found to be a pyogenic granuloma. She had no other medical history.

Investigations

On examination, a mass with a dark necrotic surface was noted in the right nasal passage extending to the right anterior naris. It was not possible to pass a flexible nasoendoscope into the right nasal passage due to the mass.

Contrast enhanced CT showed a minimally enhancing focal lesion in the anterior right nasal cavity measuring 1.9×2.3 cm, inseparable from the inferior turbinate and lateral wall of the right nasal cavity. There was no clear site of attachment and the poor definition of margins on CT raised suspicion of a non-benign cause (figure 1).

Figure 1.

Contrast-enhanced axial and coronal CT images demonstrating a minimally enhanced focal lesion occupying the anterior right nasal cavity with no clear site of attachment noted.

MRI was performed to further assess the lesion. This was done without gadolinium contrast at patient request due to her breastfeeding status. It confirmed a 2.1 cm well-defined mass lesion with encapsulated clear margins of high T2 and intermediate T1 signal anteromedial to and effacing, rather than invading, the right inferior turbinate (figures 2 and 3). MRI further delineated a narrow attachment between the mass and the mucosa of the nasal septum (figure 2).

Figure 2.

T2-weighted axial and sagittal MRI images demonstrating a high signal mass lesion abutting and effacing the anteromedial aspect of the right inferior turbinate. The mass is well defined and encapsulated with clear margins (red arrows) and appears adherent only to the nasal septum (green arrow).

Figure 3.

T1-weighted coronal MRI demonstrating a mass lesion in the right nasal cavity.

It was felt that surgical excision was required to ultimately reach a diagnosis and exclude malignancy. With the benefit of MRI, it was decided that a simple endonasal operation would suffice as the narrow attachment between the mass and mucosa was noted, and the absence of invasion of surrounding structures increased the likelihood of a benign pathology. The patient was counselled appropriately.

Treatment

The patient underwent complete excision of this lesion via an endonasal approach under general anaesthetic. Intraoperatively, the origin of the mass was found to originate from the nasal septum.

Macroscopically, it was a grey ovoid nodule with a smooth surface. Histopathological analysis of the specimen confirmed a benign pyogenic granuloma.

Outcome and follow-up

The patient was followed up in clinic, and at 3 months there was no evidence of recurrence.

Discussion

PGG is a benign fibrovascular tumour-like growth found commonly in the skin and oral cavity. Histologically, it is characterised by vascular proliferation and organisation into lobular aggregates or granulation-like tissue.⁵ When found in the pregnant patient, it is termed pyogenic granuloma gravidarum and is clinically and histologically identical to that found in the non-gravid patient. It is often referred to as a ‘pregnancy tumour’ and occurs in less than 5% of pregnant patients.¹ The majority of these arise within the oral cavity, especially the gingivae. The nasal fossa is a relatively rare site with reported incidence 7%–10% in these patients.⁵

Nasal PGG presents most commonly with unilateral epistaxis,⁶ as found in this case. Other symptoms include pain and nasal obstruction. Adult case series looking solely at nasal PGG have quoted the nasal septum as the most common site, being seen in up to 76% of patients. The involvement of the inferior turbinate is rare and ranges between 12% and 20%.^{3 7} Clinical examination may reveal a bloody or ulcerated mass, and steps must be taken to rule out malignancy; differential diagnoses include basal and squamous cell carcinomas, Kaposi’s sarcoma, angiofibromas and warts.⁶

Aetiology has been linked to a number of factors including trauma or chronic low-grade irritation and increased levels of oestrogen and progesterone. During pregnancy, the high circulating levels of these hormones are thought to cause an exaggerated response to pre-existing local irritation or trauma on the mucosal surfaces.⁸ This stimulates endothelial proliferation at these sites resulting in granulation tissue formation as seen in pyogenic granuloma.^{4 9} Nasal cavity trauma can arise from nose picking, previous packing, nasal fracture, prior surgery and cocaine use.⁹

Postparturition, the fall in circulating oestrogen and progesterone is thought to encourage regression of the lesion although the molecular basis for this is poorly understood.⁵ As such, surgical treatment is usually reserved either for cases that fail to achieve complete involution or those in which malignancy must be excluded.

Imaging plays a crucial role in characterising and delineating the extent of the nasal mass¹⁰ and guides surgical planning. While CT is useful in assessing the bony architecture of the sinonasal tract, MRI is superior in the evaluation of soft-tissue masses and their local extension particularly into the skull base, postnasal space, orbit and cranium.¹¹ High homogeneous T2 signal intensity is indicative of an inflammatory or infective cause, whereas intermediate heterogeneous T2 signal intensity is more suggestive of tumour.¹¹ This is important given the high frequency of concurrent inflammatory sinusitis with nasal lesions.

The CT features of pyogenic granuloma have been reported in the literature as an ‘intensely enhancing soft tissue mass with or without bony destruction or invasion into the paranasal sinuses.’¹² MRI features have been less well documented although consensus from a 2013 review conducted by Yang et al ¹³ suggested that the characteristic features of nasal pyogenic granuloma are high heterogeneous T2 signal intensity with a thin peripheral isointense or hypointense ring. The marked enhancement is attributed to the high vascularity of these lesions and T1-weighted images usually demonstrate homogeneous isointensity to grey matter.

This report highlights a rare case of PGG not only for its location in the nasal cavity but also for its recurrent nature and its failure to regress post partum. It also demonstrates the complementary nature of MRI in the evaluation of a sinonasal mass and in determining the surgical approach preoperatively, hence allowing appropriate patient counselling. Finally, it contributes to the otherwise sparse literature on MRI findings of nasal pyogenic granuloma.

Learning points.

• Consider nasal pyogenic granuloma in the differential diagnosis for pregnant patients presenting with epistaxis.

• Steps should be taken to exclude malignancy in patients with an unresolving nasal mass.

• Imaging plays a crucial role in the delineation of a nasal mass.

• MRI is superior to CT in the evaluation of a soft-tissue mass in the skull base and postnasal space.

• MRI may be more useful than CT in guiding surgical technique in the preoperative planning of a nasal mass.