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Eardrum color and the imaging diagnosis of middle ear disease: otoscopic - radiologic correlation of retrotympanic lesions. Poster No.: C-1266 Congress: ECR 2013 Type: Educational Exhibit Authors: J. C. Tortajada Bustelo , M. Prenafeta Moreno , S. Perez 1 1 2 1 1 Aguilera , M. Cufí Quintana , C. Spinu , V. P. BELTRÁN 1 1 1 SALAZAR , A. Carvajal Diaz , M. Zauner Jakubik , A. Rovira 1 1 2 Gols ; Sabadell/ES, Arenys de Munt-Barcelona/ES Keywords: Inflammation, Diagnostic procedure, MR, CT, Neuroradiology brain, Ear / Nose / Throat DOI: 10.1594/ecr2013/C-1266 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. 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Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 59 www.myESR.org Page 2 of 59 Learning objectives The main objective of this communication is to establish a correlation between the clinical and radiological findings for different diseases of the middle ear in which the tympanic membrane remains intact, especially for retrotympanic lesions that are associated with abnormal coloring of the eardrum on otoscopy. Background Retrotympanic lesions are usually discovered during otoscopic examination for hearing loss, otalgia, or tinnitus. Most of these lesions are associated with abnormal whitish, reddish, or bluish coloring of the eardrum, and the coloring helps limit the differential diagnosis. (Fig. 1 on page 6 ) # A whitish eardrum: usually suggests congenital cholesteatoma; other diagnoses like primary tumors of the middle ear are less common. # A reddish eardrum: the paragangliomas are most likely, though vascular malformations are also possible. # A bluish eardrum: suggests different diagnoses like a dehiscent jugular bulb, a cholesterol granuloma, or meningoencephalocele. Page 3 of 59 Fig. 1: We classify the diseases according to the otoscopic findings into three major groups: red, blue, and white lesions. References: - Sabadell/ES High resolution CT and MRI of the temporal bone are mandatory when a retrotympanic mass is seen at otoscopy. CT and MRI are complementary: which technique is most useful depends on the disease suspected in the clinical evaluation. » We make a schematic overview of the basic anatomy of the ear and the normal otoscopy (Fig. 2 on page 7 ,Fig. 3 on page 8 ): Page 4 of 59 Fig. 2: Anatomic diagram of the ear: 1. Malleus, 2. Incus, 3. Stapes, 4. Cochlea, 5. Semicircular canals, 6. Facial nerve, 7. Vestibular nerve, 8. Cochlear nerve, 9. Tympanic membrane, 10. Epitympanic recess, 11. Eustachian tube, 12. Carotid. A. Ear canal, B. Middle ear, C. Inner ear, D. Internal auditory canal. References: - Sabadell/ES Page 5 of 59 Fig. 3: A- Otoscopy (right ear): 1. Flaccid portion, 2. Tense portion, 3. Manubrium, 4. Lateral process of the malleus, 5. Anterior fold of the malleus, 6. Posterior fold of the malleus, 7. Annulus, 8.Umbo, 9. Cone of light. B- Tympanic quadrants: The manubrium divides the eardrum into the anterior and posterior regions. If a line is also projected perpendicularly at the level of the umbo, the 4 classic quadrants are obtained: anterosuperior, posterosuperior, anteroinferior, & posteroinferior. References: - Sabadell/ES Images for this section: Page 6 of 59 Fig. 1: We classify the diseases according to the otoscopic findings into three major groups: red, blue, and white lesions. Page 7 of 59 Fig. 2: Anatomic diagram of the ear: 1. Malleus, 2. Incus, 3. Stapes, 4. Cochlea, 5. Semicircular canals, 6. Facial nerve, 7. Vestibular nerve, 8. Cochlear nerve, 9. Tympanic membrane, 10. Epitympanic recess, 11. Eustachian tube, 12. Carotid. A. Ear canal, B. Middle ear, C. Inner ear, D. Internal auditory canal. Page 8 of 59 Fig. 3: A- Otoscopy (right ear): 1. Flaccid portion, 2. Tense portion, 3. Manubrium, 4. Lateral process of the malleus, 5. Anterior fold of the malleus, 6. Posterior fold of the malleus, 7. Annulus, 8.Umbo, 9. Cone of light. B- Tympanic quadrants: The manubrium divides the eardrum into the anterior and posterior regions. If a line is also projected perpendicularly at the level of the umbo, the 4 classic quadrants are obtained: anterosuperior, posterosuperior, anteroinferior, & posteroinferior. Page 9 of 59 Imaging findings OR Procedure details _ _RED EARDRUM_ _ 1- TYMPANIC AND JUGULAR GLOMUS: The extraadrenal neuroendocrine system is a complex system made up of chemoregulating tissues dispersed throughout the body. An isolated focus of such tissue is a paraganglion, and all these foci considered together constitute the paraganglia. Paragangliomas are tumors originating in the paraganglia. As such, they can occur in many different sites. Within the head and neck, the four most common sites are the carotid body at the level of the carotid bifurcation (carotid glomus), the jugular (jugular glomus), along the vagus nerve (glomus vagale), and in the middle ear in relation to the tympanic nerve (tympanic glomus). # Otoscopy: pulsatile red retrotympanic mass in lower quadrants. It is important to assess the status of the fibrocartilaginous ring of the eardrum and the floor of the external ear canal, because changes to these areas orient the diagnosis toward jugular glomus. Fig. 4 on page 32 # Clinical presentation: Pulsatile tinnitus (90%), conductive hearing loss, facial paralysis (5%). # Imaging findings: • Tympanic glomus: (Fig. 5 on page 33) This is the most common tumor of the middle ear; it presents as a soft-tissue-density mass with its base at the level of the promontory of the tympanic cavity. The largest ones can erode the bony wall of the middle ear. The floor of the middle ear is usually spared; a dehiscent or permeative floor suggests a jugulotympanic component. Contrast-enhanced CT with bone window reconstructions are recommended; MRI should be reserved for cases in which a jugulotympanic component is suspected. Page 10 of 59 Fig. 5: CT bone: a sessile mass on the cochlear promontory (yellow asterisk). The jugular canal and the floor of the middle ear cavity are intact (yellow circle). MR T1 Gd: reveals a focal enhancing mass on cochlear promontory (blue circle). Angiography: shows a small vascular mass (red circle). References: - Sabadell/ES • Jugular glomus: (Fig. 6 on page 34) This tumor presents as a mass at the level of the jugular foramen. CT: Lytic permeative bone pattern along the superolateral margin of the jugular foramen. MRI: Lesions >2 cm present the characteristic "salt and pepper" pattern in T1-weighted sequences, in which salt refers to hyperintense foci caused by small hemorrhages or areas of slow flow and pepper refers to hypointense foci caused by areas of high arterial flow. Page 11 of 59 Fig. 6: CT: Lytic-permeative pattern in the jugular foramen (circle), superolateral growth vector toward the middle ear (yellow asterisk). MR: Salt and pepper pattern, with multiple signal voids inside due to hypertrophic neoplastic vessels (arrows), and intense contrast enhancement. References: - Sabadell/ES 2- ABERRANT COURSE OF THE INTRAPETROUS CAROTID ARTERY: Aberrant intracranial internal carotid (ICA) is a congenital vascular anomaly. # Otoscopy: red vascular-appearing mass lying in the anteroinferior mesotympanum. # Clinical presentation: pulsatile tinnitus or asymptomatic (an incidental finding). # Imaging findings: Page 12 of 59 CT findings are pathognomonic: axial bone CT shows a tubular lesion that crosses the middle ear cavity from the cochlear promontory to rejoin the horizontal petrous ICA. Fig. 7 on page 35 Angiography shows the ICA in a more posterolateral course; a distinct angulation resembling a "7" is often present, together with a change in contour and caliber ("pinched appearance") before the segment resumes its normal course. Fig. 8 on page 36 Fig. 7: CT: Tubular structure coursing horizontally from the posterior cochlear promontory to the union with the petrous segment (yellow circle). Coronal-CT shows a soft tissue mass on the cochlear promontory (yellow asterisk). References: - Sabadell/ES Page 13 of 59 Fig. 8: Angiography: Lateral extension of the petrous segment of the ICA (characteristic "7" shape, red circle). Stenosis at the point where the aberrant ICA joins the petrous segment (arrow). References: - Sabadell/ES 3- OTOSCLEROSIS: Otosclerosis is a metabolic bone disease of unknown etiology. The disease begins with an otospongiotic phase of bone resorption (called otospongiosis) which is followed by an otosclerotic phase when osteoclasts are replaced by osteoblasts and dense sclerotic bone (called otosclerosis). The process usually starts in the region of the oval window (fenestral otosclerosis); the footplate becomes fixed and produces conductive hearing loss. It can also occur around the cochlea (retrofenestral otosclerosis). Page 14 of 59 # Otoscopy: During the otospongiotic phase, when an active focus reaches the periosteal surface of the promontory, a red-pink glow may be seen through the tympanic membrane (Schwartze's sign). # Clinical presentation: unexplained progressive conductive hearing loss in young adults, twice as common in women than in men. # Imaging findings: CT: In the earlier phase, CT shows a radiolucent focus involving the oval window. In the chronic phase, bone sclerosis appears along the oval window, which may become occluded by a healed plate. Fig. 9 on page 37 MRI: Nonspecific findings. MRI can show contrast-enhancing punctuate foci in the medial wall of the middle ear. Fig. 9: CT demostrate a case of combined otosclerosis: a otosclerotic fenestral plaque ( 1 ) and retro-fenestral otospongiosis focus ( 2,3 ). Schwartze's sign is a reddish Page 15 of 59 retrotympanic image in the region of the promontory, secondary to foci of otospongiosis ( 3 ). References: - Sabadell/ES _ _BLUE EARDRUM_ _ 1- DEHISCENT JUGULAR BULB: This is a normal venous variant with superior and lateral extension of the jugular bulb into the middle ear cavity through a dehiscent sigmoid plate. # Otoscopy: blue posteroinferior retrotympanic vascular mass. # Clinical presentation: asymptomatic (an incidental finding). # Imaging findings: CT shows a focally dehiscent sigmoid plate with a mass protruding into the posteroinferior middle ear; after contrast administration, the mass shows the same enhancement as the jugular bulb. Fig. 10 on page 47 This condition is most often associated with a high riding jugular bulb. Page 16 of 59 Fig. 10: CT: Superior and lateral extension of the jugular bulb through a dehiscent bone plate into the hypotympanum (yellow arrows). Associated with a high jugular bulb. References: - Sabadell/ES 2- CHOLESTEROL GRANULOMA: Cholesterol granulomas form from the response of tissues to cholesterol crystals. They can develop in any part of the temporal bone, although they usually arise in the middle ear. There are two hypotheses about their pathogenesis: • • Obstruction-vacuum hypothesis: the chronic obstruction of the middle ear decreases pressure, resulting in engorgement of the mucosa and predisposing blood vessels to rupture. Blood breakdown products, primarily cholesterol crystals, cause an inflammatory response. Exposed marrow hypothesis: Enlarging mucosa creates bony defects into the hematopoietic marrow, causing recurrent microhemorrhages. Blood breakdown to cholesterol crystals incites a foreign cell response and air obstruction secondary to inflammation. Page 17 of 59 # Otoscopy: non-pulsatile blue retrotympanic mass (blue eardrum). # Clinical presentation: blue eardrum with slow conductive hearing loss in patients with a history of recurrent middle ear otitis. # Imaging findings: (Fig. 11 on page 39) CT: Nonspecific findings. Diffuse middle ear mass, without ossicular loss or bone remodeling. MRI: The most characteristic finding is the high T1 signal from the paramagnetic effect of extracellular methemoglobin. T2-weighted sequences show a hyperintense center (granulation tissue) and a hypointense periphery (hemosiderin deposits)* Fig. 11: CT: Diffuse occupation of the middle ear and mastoid cells without bone erosions. Bulging tympanic membrane (arrows). MR: Hypersignal in T1-weighted Page 18 of 59 sequences is diagnostic, this is due to the paramagnetic effects of extracellular methemoglobin. Differential diagnosis with traumatic hemotympanum (correlation with otoscopic findings!). References: - Sabadell/ES *Differential diagnosis with the traumatic hemotympanum: Hemotympanum Fig. 12 on page 40 Hemotympanum is the accumulation of blood in the middle ear with an intact tympanic membrane secondary to trauma. Otoscopy shows blood in the middle ear after recent trauma. Imaging findings: CT: associated with bone fractures. MRI: high signal on T1-weighted images secondary to the paramagnetic effect of methemoglobin, without expansion of the middle ear. Clinical presentation: acute conductive hearing loss. Page 19 of 59 Fig. 12: CT: shows nonspecific occupation of the cavities of the middle ear (yellow asterisk) with two lines of temporal bone fracture, one longitudinal and other transversal (blue arrows). Bulging tympanic membrane. References: - Sabadell/ES 3- MENINGOCELE AND MENINGOENCEPHALOCELE IN THE MIDDLE EAR: In meningoceles, the meninges herniate, and in meningoencephaloceles, brain parenchyma also herniates. Fig. 13 on page 38 Most cases (58.97%) occur after surgery; 20% of cases are idiopathic, 11.28% occur after trauma, 9.23% after infection, and 0.51% after radionecrosis. Page 20 of 59 Fig. 13: Schematic image of middle ear meningoencephalocele and meningocele: They appear as a mass of middle ear associated with a dehiscent tegmen tympani. In the case of meningocele occurs a herniation of the meninges, and in the case of meningoencephalocele occurs a herniation of meninges and brain parenchyma. References: - Sabadell/ES # Otoscopy: a soft, pulsatile avascular mass protruding through the tegmen. # Clinical presentation: asymptomatic (an incidental finding). # Imaging findings: CT shows a mass in the cavities of the middle ear associated with a dehiscence of the tegmen timpani. MRI orients the diagnosis, showing: for meningoceles, a mass with the signal intensity of CSF (hyperintense on T2-weighted sequences and hypointense on T1-weighted sequences) Fig. 14 on page 48; whereas, for meningoencephaloceles, the mass is Page 21 of 59 continuous with brain tissue and isointense with respect to brain tissue. Fig. 15 on page 45 Fig. 14: Postsurgical meningocele: The CT shows a dehiscent tegmen tympani (red asterisk) and a middle ear mass, with a T2-weighted MR liquid signal like cerebrospinal fluid (circle). References: - Sabadell/ES Page 22 of 59 Fig. 15: Postsurgical meningoencephalocele: CT shows a dehiscent tegmen tympani (arrow) associated with a middle ear soft tissue mass (circle). MR T2 shows a brain parenchyma herniation into the middle ear cavity. References: - Sabadell/ES _ _WHITE EARDRUM_ _ 1- CONGENITAL CHOLESTEATOMA: Congenital cholesteatomas are diffuse middle ear masses formed by aberrant epithelial remnants of exfoliated keratin within stratified squamous epithelium. They result from abnormal congenital migration of external canal ectoderm to the middle ear cavity beyond the tympanic ring. They account for only 5% of all temporal bone cholesteatomas. Page 23 of 59 # Otoscopy: avascular middle ear mass with an intact tympanic membrane, although white attic retraction pocket formation is often seen. # Clinical presentation: History of recurrent middle ear otitis with conductive hearing loss. # Imaging findings: Common locations are the anterosuperior middle ear (adjacent to the eustachian tube), posterior epitympanum, and near the stapes. CT: A well-circumscribed middle ear mass with ossicular erosions, although bone erosions are less common than in acquired cholesteatoma. Fig. 16 on page 44 MRI: An iso- or hypo-intense mass in T1-weighted sequences, with peripheral enhancement and intermediate intensity in T2-weighted sequences. The most characteristic finding is the high signal in diffusion-weighted imaging. Fig. 17 on page 43 Page 24 of 59 Fig. 16: CT: Soft-tissue occupation, with bone erosions, both in the ossicular chain (circle) and in the bony margins of the cavity, especially in the attic wall (arrow). References: - Sabadell/ES Page 25 of 59 Fig. 17: MR: Hypersignal in diffusion sequences is diagnostic (circle). No enhancement, except in the periphery of the lesion (arrows). References: - Sabadell/ES 2- BENIGN NONVASCULAR TUMORS OF THE MIDDLE EAR: These tumors are rare, and the most typical are: # Adenoma (Fig. 18 on page 50, Fig. 19 on page 49, Fig. 20 on page : 46) Middle ear adenomas are very rare tumors that arise from modified respiratory mucosa. # Schwannoma: Middle ear space schwannomas may originate from the nerves of the tympanic cavity or may originate from other nerves outside the middle air space and extend into the cavity (Fig. 21 on page 51). Schwannomas arising intrinsically in the middle ear may potentially originate from the facial nerve, the chorda tympani nerve, the tympanic branch of the glossopharyngeal nerve (Jacobson's nerve), or the auricular branch of the vagus nerve (Arnold's nerve). Page 26 of 59 # Meningioma: Ectopic meningiomas can arise from arachnoid cells in the middle ear, secondary to abnormal embryonic migration. The diagnosis requires a primary intracranial lesion to be ruled out. # Otoscopy: White / pink retrotympanic mass. # Clinical presentation: Conductive hearing loss. # Imaging findings: (nonspecific) CT: Soft-tissue middle ear mass with a well-pneumatized mastoid (no findings indicative of chronic otitis media). Meningiomas can present calcifications and permeative-sclerotic changes in affected bone (tegmen timpani or mastoid bones) MRI: Intermediate signal on T1-weighted sequences and enhancement after contrast administration. Hyperintense on T2 -weighted sequences. Meningiomas show strong enhancement associated with a dural tail. Page 27 of 59 Fig. 18: CT: Nonspecific occupation of the cavities of the middle ear, with sclerotichyperostotic changes in the bony margins. References: - Sabadell/ES Page 28 of 59 Fig. 19: RM: Diffuse enhancement after contrast administration. No hypersignal in DWI (Differential diagnosis with cholesteatoma). The definitive diagnosis is histological. References: - Sabadell/ES Page 29 of 59 Fig. 21: CT: shows a middle ear soft tissue mass (yellow circle) with bony remodeling and dehiscent tegmen tympani (green arrow), that causes a bulging tympanic membrane. MR: reveals a lesion with a large intracranial component that extending into middle ear cavity (red asterisk). The lesion presents nonspecific T2 hyperintensity and contrast enhancement. References: - Sabadell/ES These lesions have similar clinical and imaging presentations, and their differential diagnosis is histological. Fig. 20 on page 46 3- SEROUS OTITIS MEDIA: This is defined as the accumulation of fluid in the middle ear with an intact tympanic membrane in the absence of signs and symptoms or acute infection. The fluid can be mucoid, serous, or a combination of the two. Page 30 of 59 # Otoscopy: Intact eardrum with air levels or air bubbles inside, although more chronic cases can present with a bluish eardrum. # Clinical presentation: conductive hearing loss. # Imaging findings: Although the diagnosis is usually reached by clinical and otoscopic examination, CT shows a lesion occupying the middle ear and extending to the eustachian tube in the absence of bone erosions. Fig. 22 on page 42 It is important to check the nasopharynx for neoplasms, especially in adults. Fig. 23 on page 41 Fig. 22: CT: shows a diffuse and nonspecific middle ear and mastoid cells occupation without bone erosions, and with hyperintense T2 signal. References: - Sabadell/ES Page 31 of 59 Fig. 23: Inadequate middle ear ventilation causes a diffuse mucoid occupation of the middle ear and mastoid cells, with T2 hyperintensity (red asterisk). Eustachian tube with mucoid material (red arrow). T1-weighted contrast MRI shows a nasopharyngeal enhancing mass (yellow circle). References: - Sabadell/ES Images for this section: Page 32 of 59 Fig. 4: Otoscopic diagnosis between tympanic and jugular / jugulotympanic glomus. Page 33 of 59 Fig. 5: CT bone: a sessile mass on the cochlear promontory (yellow asterisk). The jugular canal and the floor of the middle ear cavity are intact (yellow circle). MR T1 Gd: reveals a focal enhancing mass on cochlear promontory (blue circle). Angiography: shows a small vascular mass (red circle). Page 34 of 59 Fig. 6: CT: Lytic-permeative pattern in the jugular foramen (circle), superolateral growth vector toward the middle ear (yellow asterisk). MR: Salt and pepper pattern, with multiple signal voids inside due to hypertrophic neoplastic vessels (arrows), and intense contrast enhancement. Page 35 of 59 Fig. 7: CT: Tubular structure coursing horizontally from the posterior cochlear promontory to the union with the petrous segment (yellow circle). Coronal-CT shows a soft tissue mass on the cochlear promontory (yellow asterisk). Page 36 of 59 Fig. 8: Angiography: Lateral extension of the petrous segment of the ICA (characteristic "7" shape, red circle). Stenosis at the point where the aberrant ICA joins the petrous segment (arrow). Page 37 of 59 Fig. 9: CT demostrate a case of combined otosclerosis: a otosclerotic fenestral plaque ( 1 ) and retro-fenestral otospongiosis focus ( 2,3 ). Schwartze's sign is a reddish retrotympanic image in the region of the promontory, secondary to foci of otospongiosis ( 3 ). Page 38 of 59 Fig. 13: Schematic image of middle ear meningoencephalocele and meningocele: They appear as a mass of middle ear associated with a dehiscent tegmen tympani. In the case of meningocele occurs a herniation of the meninges, and in the case of meningoencephalocele occurs a herniation of meninges and brain parenchyma. Page 39 of 59 Fig. 11: CT: Diffuse occupation of the middle ear and mastoid cells without bone erosions. Bulging tympanic membrane (arrows). MR: Hypersignal in T1-weighted sequences is diagnostic, this is due to the paramagnetic effects of extracellular methemoglobin. Differential diagnosis with traumatic hemotympanum (correlation with otoscopic findings!). Page 40 of 59 Fig. 12: CT: shows nonspecific occupation of the cavities of the middle ear (yellow asterisk) with two lines of temporal bone fracture, one longitudinal and other transversal (blue arrows). Bulging tympanic membrane. Page 41 of 59 Fig. 23: Inadequate middle ear ventilation causes a diffuse mucoid occupation of the middle ear and mastoid cells, with T2 hyperintensity (red asterisk). Eustachian tube with mucoid material (red arrow). T1-weighted contrast MRI shows a nasopharyngeal enhancing mass (yellow circle). Page 42 of 59 Fig. 22: CT: shows a diffuse and nonspecific middle ear and mastoid cells occupation without bone erosions, and with hyperintense T2 signal. Page 43 of 59 Fig. 17: MR: Hypersignal in diffusion sequences is diagnostic (circle). No enhancement, except in the periphery of the lesion (arrows). Page 44 of 59 Fig. 16: CT: Soft-tissue occupation, with bone erosions, both in the ossicular chain (circle) and in the bony margins of the cavity, especially in the attic wall (arrow). Page 45 of 59 Fig. 15: Postsurgical meningoencephalocele: CT shows a dehiscent tegmen tympani (arrow) associated with a middle ear soft tissue mass (circle). MR T2 shows a brain parenchyma herniation into the middle ear cavity. Page 46 of 59 Fig. 20: The definitive diagnosis is made by means of the histological and immunohistochemical analysis, which shows a tissue formed of fibrous stroma and cellular nests in the form of cords alternating with trabecular and glandular areas (C). The positivity of some cells to the anti-enolase neuro-specific antibodies (D) confirmed the neuroendocrine differentiation of these tumors. Page 47 of 59 Fig. 10: CT: Superior and lateral extension of the jugular bulb through a dehiscent bone plate into the hypotympanum (yellow arrows). Associated with a high jugular bulb. Page 48 of 59 Fig. 14: Postsurgical meningocele: The CT shows a dehiscent tegmen tympani (red asterisk) and a middle ear mass, with a T2-weighted MR liquid signal like cerebrospinal fluid (circle). Page 49 of 59 Fig. 19: RM: Diffuse enhancement after contrast administration. No hypersignal in DWI (Differential diagnosis with cholesteatoma). The definitive diagnosis is histological. Page 50 of 59 Fig. 18: CT: Nonspecific occupation of the cavities of the middle ear, with sclerotichyperostotic changes in the bony margins. Page 51 of 59 Fig. 21: CT: shows a middle ear soft tissue mass (yellow circle) with bony remodeling and dehiscent tegmen tympani (green arrow), that causes a bulging tympanic membrane. MR: reveals a lesion with a large intracranial component that extending into middle ear cavity (red asterisk). The lesion presents nonspecific T2 hyperintensity and contrast enhancement. Page 52 of 59 Conclusion In retrotympanic lesions, it is fundamental to analyze the clinical and otoscopic findings, especially the color of the eardrum, together with the imaging findings. We present three tables that summarize the most useful findings for the main conditions described in this poster: Fig. 24: Reddish eardrum. References: - Sabadell/ES Page 53 of 59 Fig. 25: Bluish eardrum. References: - Sabadell/ES Page 54 of 59 Fig. 26: Whitish eardrum. References: - Sabadell/ES Images for this section: Page 55 of 59 Fig. 24: Reddish eardrum. Page 56 of 59 Fig. 25: Bluish eardrum. 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