Most Frequently Missed Diagnosis: Retropharyngeal Suppurative Lymphadenitis

Transcription

1 Mst Frequently Missed Diagnsis: Retrpharyngeal Suppurative Lymphadenitis J Shah, MD; L Lanier, MD; C L Sistrm, MD; D Rajderkar, MD; A Ghaffari, MD; A Mancus, MD;I M Schmalfuss, MD University f Flrida, Department f Radilgy Cntact: shahjl@radilgy.ufl.edu The authrs have n financial disclsure in regard t this educatinal exhibit.

2 Backgrund: Cmputer aided nline simulatin (SIM) f emergency imaging studies was develped Designed t test residents fr readiness fr call Prviding prficient & bjective assessment f resident cmpetence in the emergency/critical care imaging & affirmatin f milestne achievements

3 Backgrund: 8 hur simulatin f 65 emergent & critical care cases f varying degrees f difficulty, including nrmal studies Presentatin via full DICOM image sets Dictatin f free respnses int text bxes labelled: Critical findings Incidental findings Acuity ranking

4 Results: SIM was taken by 103 first (R1) & secnd (R2) year residents frm 9 USA radilgy training prgrams in 2014 Suppurative retrpharyngeal space (RPS) lymphadenitis was presented 100% f residents failed t make the crrect diagnsis Incrrect answers included: RPS abscess (48%) Peritnsillar abscess (24%) Tnsillar abscess (15%) Abscess withut lcalizatin (1%)

5 Results: SIM was taken by 103 first (R1) & secnd (R2) year residents frm 9 USA radilgy training prgrams in 2014 Suppurative retrpharyngeal space (RPS) lymphadenitis was presented 100% f residents failed t make the crrect diagnsis Cnclusin: Significant cgnitive gap exists in differentiating suppurative RPS lymphadenitis frm abscess placing patients at risk fr unnecessary surgical prcedure

6 Teaching Pints: Familiarize the radilgist with clinical and imaging findings f RPS suppurative lymphadenitis Discuss clinical and imaging features f mimics f RPS suppurative lymphadenitis t imprve diagnstic cmpetency

7 Outline: SIM case presentatin Discussin f nrmal RPS anatmy Presentatin f clinical & imaging findings f RPS suppurative lymphadenitis and ptential cmplicatins Review f mimics f RPS suppurative lymphadenitis

8 SIM Case: 9 mnth ld male with fever & decreased neck mvement * Axial cntrast enhanced CT (CECT) shws mild narrwing f the upper airway (*) caused by a fcal, rim enhancing hypdensity in the right RPS with marked surrunding edema. The lateral nature f the disease is nt cnsistent with a RPS abscess but rather with suppurated RPS lymphadenitis.

9 RPS Anatmy Bundaries: Anterir: Middle layer f deep cervical fascia Psterir: Deep layer f deep cervical fascia Lateral: Alar fascia (arises frm deep cervical fascia) Superir: Skull base Inferir: Fusin f middle & deep cervical fascia frm T2 t T6 Cntents: Lse cnnective tissue Lateral and medial RPS lymph ndes

10 RPS Imaging Anatmy: Axial plane - CT Axial CECT shws thin layer f fat in the RPS between the pharyngeal cnstrictr & lngus clli muscles. RPS lymph ndes are divided int lateral & medial grups (2) with the lateral being lcated medial t the internal cartid artery (ICA) while the medial nes are in midline.

11 RPS Imaging Anatmy: Axial plane - MRI Axial T1+Gd image reveals a nrmal lateral RPS lymph nde lcated immediately medial t the ICA and lateral t the lngus clli muscle. Axial T2 image in an infant shws a nrmal medial RPS lymph nde lcated in the midline between the lngus clli muscles and a nrmal left lateral RPS lymph nde medial t the ICA.

12 RPS Imaging Anatmy: Sagittal plane Danger space is a ptential space while RPS is an actual space. In a nrmal patient, the tw cannt be distinguished with a small fat plane seen in the RPS n T1 image.

13 RPS Imaging Anatmy: Sagittal plane Sagittal CT in bne algrithm in a different patient shws air tracking inferirly int the mediastinum psterir t the esphagus cnsistent with the danger space as the RPS stps at the thracic inlet level.

14 RPS Suppurative Lymphadenitis Demgraphics: Mst cmmn in children between ages f 2 t 6 years Teens and yung adults ccasinally affected N gender predilectin Presentatin: Yung children - high fevers, feeding prblems and airway cmprmise Older children - fevers, sre thrat, dynphagia, and neck pain Pathphysilgy: Staphylcccus r Streptcccus head & neck infectin -> RPS reactive lymphadenpathy -> RPS suppurative lymphadenitis -> RPS abscess

15 RPS Diagnstic Cnfusin In RPS space: RPS suppurative lymphadenitis RPS abscess RPS edema Necrtic RPS ndal metastasis In adjacent anatmical structures: Tnsillar abscess Peritnsillar abscess Lngus clli calcific tendinitis Sft tissue tumrs / cysts

16 Increasing Diagnstic Accuracy Characteristic RPS Suppurative Lymphadenitis RPS Abscess RPS Edema Fluid Distributin Unilateral Fills the RPS frm side t side Fills the RPS frm side t side Cnfiguratin and mass effect Runded r vid, mass effect depends n size Runded r vid; mass effect depends n size Bw-Tie cnfiguratin n axial images, sagittal images demnstrates tapered margins. Mild t n mass effect Enhancing Wall Smetimes Always N Necrtic metastatic RPS lymph ndes mimic RPS suppurative lymphadenitis but affect elderly patients.

17 RPS Suppurative Lymphadenitis Axial CECT images in a 8 year ld by with dysphagia, fever & neck pain reveals a hypdense, rim enhancing lesin in the right RPS as the lesin is medial t ICA & psterir t the pharyngeal cnstrictr muscle. Ntice the reactive lymphadenpathy in level II with subtle edema in the RPS. The unilateral nature f the lesin is cnsistent with RPS suppurative lymphadenitis with clear fluid & negative cultures n aspiratin, cnfirming the diagnsis and ruling ut RPS abscess.

18 RPS Abscess CECT reveals an irregular, rim enhancing hypdensity in the RPS. The small air pckets & bilateral nature f the disease indicates RPS abscess rather than suppurated RPS lymph nde. This requires search fr underlying etilgy, e.g. discitis/stemyelitis as seen n sagittal T1+Gd image in this patient.

19 RPS Abscess CECT reveals a rim enhancing hypdensity in the RPS bilaterally cnsistent with RPS abscess which was related t recent anterir fusin surgery. The diagnsis f RPS abscess requires CT imaging t the carina t exclude thracic invlvement as seen in this patient. Ntice als the small abscess in the sterncleidmastid muscle.

20 RPS Edema CECT f a 60 year ld male fllwing anterir fusin surgery reveals hypdensity in the RPS bilaterally. The lack f enhancement is cnsistent with RPS edema rather than RPS abscess as seen in the patient n the prir slide. The RPS edema spntaneusly reslved with the lateral cervical spine plain film perfrmed 2 mnths later shwing nrmal thickness f the prevertebral stripe.

21 RPS Edema Nn-cntrasted CT in a 65 year ld shws hypdensity in the RPS bilaterally. The lack f mass effect, the tapered margins and additinal subcutaneus stranding are cnsistent with RPS edema rather than RPS abscess. Search fr venus thrmbsis / bstructin is required in every patient with unexplained RPS edema. Superir vena cava syndrme due t mediastinal adenpathy was cnfirmed in this patient.

22 RPS Edema Bilateral RPS edema in tw different patients related t venus thrmbphlebitis with invlvement f the internal jugular vein nly in the patient n the left and extensin int smaller neck veins in the patient n the right. Ntice that the degree f the edema des nt indicate the extent f thrmbphlebitis.

23 Necrtic RPS Ndal Metastasis CECT in a 58 year ld male reveals a fcal rim enhancing hypdensity in the right RPS. The age f the patient & the assciated large abnrmal grup IIB ndal cnglmerate withut adjacent inflammatry changes are cnsistent with metastatic disease rather than suppurative RPS adenitis. Fullness & fat plane bscuratin was seen in the right naspharynx and cnfirmed as cancer n subsequent bipsy.

24 Necrtic RPS Ndal Metastasis CECT in a 49 year ld male reveals a right, val hypdensity with rim enhancement & inflammatry thickening f the adjacent sft tissues mimicking suppurative RPS adenitis. Hwever, in an adult patient this is a necrtic RPS metastasis until prven therwise and requires search fr an underlying malignancy in particular f the rpharynx & thyrid gland as in this patient.

25 RPS Pathlgy - Management Varies based n pathlgy Management RPS Suppurative Lymphadenitis RPS Abscess RPS Edema Treatment Intravenus antibitics; mst patients imprve in 24 t 48 hurs Surgical drainage Nn-surgical & depending n cause f edema Additinal Recmmendatins Airway prtectin; Incisin & drainage if prgressin t RPS abscess r if the lymph nde exceeds 3 cm in shrt axis Airway prtectin; Chest CT t exclude extensin int mediastinum; Search fr underlying cause e.g. discitis / stemyelitis Airway prtectin; Search fr underlying cause e.g. venus thrmbsis / thrmbphlebitis

26 RPS Pathlgy Reprting Guidelines Is the prcess centered in the RPS lymph nde r truly in the RPS? If in RPS lymph nde, is it inflammatry indicating suppurative adenitis r neplastic? If truly in the RPS, is it infectius indicating RPS abscess r just edema? Assciated findings / cmplicatins, such as: Airway cmprmise? Venus bstructin r thrmbphlebitis? Ostemyelitis/discitis? Epidural abscess with spinal canal r crd cmprmise? Orpharyngeal r thyrid gland malignancy? Extent f disease & relatinship t cartid artery / jugular vein Are additinal studies r interventin such as aspiratin/bipsy needed t establish the crrect diagnsis?

27 Additinal RPS Lymphadenitis Mimics: Tnsillar abscess Peritnsillar abscess Lngus clli calcific tendinitis Sft tissue tumrs / cysts

28 Tnsillar versus Peritnsillar Abscess CECT in tw different patients reveals fcal fluid cllectins in the right tnsillar regin. The differentiating feature between these tw entities is the lcatin f the tnsils. In the patient with tnsillar abscess, the fluid cllectin is centered in the tnsil while the tnsil is nrmal but medially displaced in peritnsillar abscess. Bth cllectins are markedly anterir t the RPS.

29 Lngus Clli Calcific Tendinitis Clinical presentatin mimics RPS infectin: Fevers, dysphagia, dynphagia & neck pain May have elevated inflammatry markers including ESR & WBC Imaging findings n CT/MRI include: Edema within the lngus clli musculature & RPS Calcificatin f the lngus clli tendns = differentiating feature; may be subtle Treatment with NSAIDS

30 Lngus Clli Calcific Tendinitis 54 year ld male with dysphagia & fevers is referred t the hspital fr suspected discitis/stemyelitis. CT scut image reveals marked prevertebral sft tissue thickening that is caused by widened and hypdense RPS withut assciated enhancement n the CECT cnsistent with RPS edema. Ntice the small calcificatins at C2 leading t the crrect diagnsis f calcific lngus clli tendinitis.

31 Sft Tissue Tumrs / Cysts Axial T1 and T2 images in a 26 year female demnstrates a well-defined T1 hypintense & T2 hyperintense mass medial t the ICA that cmpresses the lngus clli muscle. This culd be mistaken fr a suppurative RPS adenitis. The marked enhancement n the T1+Gd image is hwever nt cnsistent with such a diagnsis. Pathlgy revealed a schwanmma likely arising frm the sympathetic chain as the patient did nt have vcal crd paralysis t indicate vagus nerve rigin.

32 Sft Tissue Tumrs / Cysts T2 images in a 60 year ld female reveal a well-defined, val, hyperintense lesin that might be mistaken fr suppurative RPS adenitis. Patient s age, lack f inflammatry changes, lcatin anterir t the ICA and the hetergeneus internal enhancement n the T1+Gd image cntradict such a diagnsis. The lcatin is characteristic f a parapharyngeal space mass with the pathlgy revealing benign minr salivary gland tumr.

33 Sft Tissue Tumrs / Cysts CECT in a 57 year ld male shws a well-defined, val, hypdense lesin medial t ICA cncerning fr suppurative RPS adenitis. Patient s age & the lack f enhancement are cntradicting such a diagnsis. Axial T1 images reveal that the lesin is spntaneusly hyperintense due t prteinaceus fluid & lcated anterir t the pharyngeal cnstrictr muscle cnsistent with a naspharyngeal retentin cyst.

34 Cnclusin: Identificatin f key clinical and imaging findings f suppurative RPS lymphadenitis requires attentin in resident educatin This exhibit fcuses n imprving cmpetence in diagnsing suppurative RPS lymphadenitis thrugh Presentatin f imaging features f cmmn pathlgies f the RPS that are cnfused with suppurative RPS adenitis (e.g. RPS abscess, RPS edema, & necrtic RPS ndal metastasis) Review f ther mimics f RPS pathlgies that affect adjacent anatmical structures (e.g. naspharynx, tnsillar & paravertebral structures)

35 References Mancus AA, Hanafee WN. Head and Neck Radilgy. Head and Neck Radilgy. Vlumes I and II. Lippinctt & Williams and Wilkins, Shefelbine SE, Mancus AA, Gajewski B, Stringer S, Sedwick JD. Pediatric retrpharyngeal lymphadenitis: differentiatin frm retrpharyngeal abscess and treatment implicatins. Otlaryngl Head Neck Surg. 2007;136(2): Hang JK, Branstetter BF, Eastwd JD, et al. Multiplanar CT and MRI f Cllectins in the Retrpharyngeal Space: Is It an Abscess? AJR. 2011;196: W426-W432. Hang JK, Vanka J, Ludwig BJ, et al. Evaluatin f Cervical Lymph Ndes in Head and Neck Cancer With CT and MRI: Tips, Traps, and a Systematic Apprach. AJR. 2013;200: W17-W25 widinline.cm