Table 1 Summary of the characteristics of the case reports in the literature review

1

Pontell 1994 [10]

5

M

1

Left neck pain, stiffness

Yes

A 3-cm hypodense retropharyngeal lesion without peripheral enhancement

Normal pharynx

Small pericardial effusion

2

Park 1997 [3]

4.5

M

7

Acute otitis media, torticollis, neck mass

Yes

Left retropharyngeal mass extending laterally into the neck; several small areas of hypolucency within the mass and associated ring enhancement

Not done

Normal

3

McLaughlin 1998 [11]

4

M

2

Neck swelling, torticollis

Yes

Extensive retropharyngeal edema crossing the midline and extending from the level of nasopharynx inferior to thoracic inlet

Not done

Normal

4

Rook 1999 [12]

4

M

sore throat, drooling

yes

Retropharyngeal abscess

Not done

Normal

5

Homicz 2000 [13]

6

F

2

Anterior neck pain, torticollis, odynophagia

Yes

A 2.8-cm low-density mass without enhancement in the retropharyngeal space

No abscess found

Normal

6

Gross 2001 [14]

9

M

7

Torticollis, headache

Yes

Retropharyngeal soft tissue swelling without enhancement

No fluid collection

Normal

7

Miao-Chiu Hung 2006 [9]

2.4

M

2

Irritability, neck swelling

Yes

Ill-defined low-density lesions in bilateral aspects of the retropharyngeal space around the level of the oropharynx

Not done

Normal

8

Langley 2008 [15]

3

M

3

Right sided neck swelling

Yes

Edema and inflammatory changes in the retropharyngeal space with associated right cervical adenitis

Not done

A small left coronary artery aneurysm

9

Ganesh 2008 [16]

8

M

1

Left neck pain, torticollis, trismus

Yes

Ill-defined hypodense lesion extending from the C2-C6 vertebral level in the posterior pharyngeal space with no contrast enhancement

2 ml pus, sterile cultures

Fusiform aneurysm of the proximal and mid right coronary artery 6.5 × 6 mm

10

Choi,2010 [2]

3

M

5

Bilateral conjunctival injection, left neck pain

Yes

Low density lesion with an irregular thick wall in the left lateral node, suggesting an abscess, and multiple lymph node enlargements in the left posterior cervical space

Purulent fluid collected

Initial- perivascular brightness around both coronary arteries

Repeated—showed mild dilation of the left main coronary artery (2.5 mm)

11

MacHaira 2012 [4]

1.3

M

1

odynophagia, torticollis, irritability

Yes

A hypodense lesion extending from C2 to C6 vertebral level in the posterior pharyngeal space and narrowing of the upper respiratory tract

Not done

Normal

12

Kritsaneepaiboon 2012; [7]

10

F

5

Irritability, Neck swelling

Yes

Bilateral cervical lymphadenopathies and retropharyngeal low-attenuation area with a mildly enhancing rim which extended to the bilateral posterior cervical spaces and downward to the thoracic inlet level

0.5 ml of serosanguinous fluid

Perivascular brightening and cuffing of right coronary artery and inner wall irregularity of left anterior descending artery

13

Kritsaneepaiboon 2012; [7]

11

M

4

torticollis

Not documented

A low-attenuation area without contrast rim enhancement at the retropharyngeal space with extension into bilateral parapharyngeal spaces and posterior cervical spaces down to the level of C5

Not done

Pericardial effusion

14

Aldemir-Kocabaş 2014 [8]

9

M

7

Sore throat, left-sided neck swelling

Yes

Prevertebral hypodense soft tissue compatible with abscess formation, extending from C2 to C5 cervical vertebrae, and deep cervical–retropharyngeal necrotic lymphadenopathy left to midline

Not done

Normal

15

Connell 2018; [3]

14

M

Odynophagia, drooling, neck swelling

Yes

A 31 × 24 mm soft tissue mass arising from the left palatine tonsil fossa with an area of central low attenuation. There was a large 3 × 3 cm lymph node anterior to the sternocleidomastoid muscle

Not done

Initial- prominent and irregular left main coronary artery The RCA was diffusely dilated and irregular, up to 5.4 mm

Repeated- persistent diffusely dilated RCA up to 5 mm

16

Chiara 2019 [1]

4

M

3

Neck pain with right cervical swelling

Yes

Multiple right side lymph nodes with a tendency towards confluence and an infiltration with intense enhancement of the sternocleidomastoid, parapharyngeal and retropharyngeal tissues with preserved respiratory space

Not done

Normal

17

Present 2019

8

F

2

Pain, swelling and redness at left cervical area

Yes

Swelling at the left retropharyngeal region with a hypodense lesion up to 45 mm with multiple enlarged and inflamed lymph nodes

A little serous fluid

Normal