Fig. 1. Chronic Suppurative Otitis Media; Necrosis of the Mastoid Process; Caries of the Roof of the Antrum; Pachymeningitis; Perforation of the Dura Mater; Abscess of the Temporal Lobe (P.).-Left temporal bone from a woman fifty-nine years of age after removal of the anterior bony wall of the auditory meatus and of the uninjured cortical portion of the mastoid process. Front view.

The tympanic membrane is thickened and perforated in its lower portion (1). The cells of the pneumatic mastoid process form a movable sequestrum (2) imbedded in a cloaca lined with granulation tissue (3). The mastoid fossa gapes in two places where the thickened mucous membrane is exposed (4). Zygomatic process (5).

Fig. 2. Specimen of Fig. 1 Seen from Above after Removal of the Tegmen Tympani and Reflection of the Dura Mater (P.).-Roof of the antrum destroyed by caries (1); the sequestrum (2) is closely applied to the dura mater (3), the latter is thickened and presents a fistula (3) surrounded by a rampart of purulent granulation tissue, communicating directly with the abscess in the temporal lobe to which the dura mater is adherent. The tympanic cavity, malleus (4), and incus (5), the mastoid antrum (6), and the Eustachian tube (7) are filled with dense masses of proliferating connective tissue.

Fig. 3. Chronic Suppurative Otitis Media; Polypi in the Tympanic Cavity; Gaping of the Tegmen Tympani; Pachymeningitis; Perforation in the Dura Mater; Abscess of the Temporal Lobe (P.).-Left temporal bone from a girl twenty-one years of age, after removal of the anterior bony wall of the auditory meatus. Complete destruction of the tympanic membrane and auditory ossicles. A polypus with five processes projects from the tympanic cavity (1). Mastoid process (2).

Fig. 4. Preparation of Fig. 3 Seen from Above after Reflection of the Dura Mater (P.).-The tegmen tympani presents a crevice with smooth edges (1). The dura mater is thickened, covered with granulations (adherent to the brain), and traversed by a fistulous tract (2) that communicated directly with the abscess in the temporal lobe. Eminentia arcuata (3); tip of pyramid removed (4).

Fig. 5. Chronic Suppurative Otitis Media; Caries of the External Auditory Meatus, of the Tegmen Tympani, and of the Petrous Portion (Neuritis of the Seventh Nerve). Necrosis of the Osseous Labyrinth; Thrombosis of the Superior Petrosal Sinus; External Pachymeningitis; Cerebellar Abscess (P.).-Left temporal bone from a scrofulous woman thirty-six years of age. Front view, after removal of the anterior bony wall of the auditory meatus. The tympanic membrane (1) is thickened, and Shrapnell's membrane (2) is perforated. The head of the malleus, the incus, and the osseous portion of the attic are destroyed (3). Polypoid granulations project from the defect in the bone and the perforation in the membrane. Mastoid process (4).

Fig. 6. Specimen of Fig. 5 Seen from Above and Behind (P.).— Carious destruction of the tegmen tympani. The gap is filled by thickened mucous membrane that is perforated at one place (1). The contiguous dura mater was thickened and covered with granulations, the superior petrosal sinus was thrombosed, and the groove was perforated (2). On the posterior surface of the pyramid is a defect with eroded edges through which the roughened and necrotic capsule of the labyrinth can be seen (3). In the adjacent portion of the cerebellum were two abscesses that communicated directly with the defect. The carious destruction begins within the tympanic cavity, in the spongy bone surrounding the compact capsule of the labyrinth, and extends to the posterior surface of the pyramid. (See Plate 26, 2.) Internal auditory meatus (4); sigmoid groove (5).

PLATE 26.

Fig. 1. Chronic Suppurative Otitis Media; Caries of the Tympanic Cavity and Labyrinth; Meningitis (P.).-Right temporal bone from a girl after removal of the anterior bony wall of the auditory meatus and tip of the pyramid. Total destruction of the tympanic membrane and auditory ossicles. The walls of the tympanic cavity are carious, the promontory and its fenestræ have been destroyed, so that the tympanic cavity (1) communicates freely with the labyrinth (2). Below and in front, over the first turn of the cochlea, a small remnant of the edge of the promontory (3) is preserved. On either side of this remnant the osseous lamina spiralis of the carious cochlea comes into view (4). On the floor of the internal auditory meatus (5) there is a carious opening (6), through which the labyrinth communicates with the internal auditory meatus. The pus from the tympanic cavity had penetrated through the labyrinth and the internal auditory meatus into the cranial cavity. Antrum (7); cells on the floor of the tympanic cavity (8).

Fig. 2. Caries of the Labyrinth; Neuritis of the Facial Nerve (P.).— Specimen of Fig. 6, Plate 25, seen from above and in front, after removal of the anterior bony wall of the auditory meatus. A large portion of the tegmen tympani is carious (1). The tympanic cavity (2) and the antrum (3) are filled with dense granulation tissue. The capsule of the labyrinth is separated by a mass of granulations from the spongy bone, so that the roughened cochlea (4) and the superior semicircular canal, which contains a carious opening (5), are freely exposed. The facial nerve (6) is swollen and infiltrated with pus. The suppurative process began in the spongy bone, and, passing around the capsule of the labyrinth, invaded the posterior surface of the pyramid. Tip of the petrous portion of the temporal bone (7); mastoid process (8).

Fig. 3. Chronic Suppurative Otitis Media; Caries of the Tympanic Cavity and Labyrinth; Destruction of the Seventh Nerve; Meningitis (P.). Petrous portion of the right temporal bone from a phthisical subject, fifty-nine years of age. The wall of the promontory contains two fistula (1) that established a communication between the tympanic cavity and the interior of the cochlea. The lower portion of the Fallopian canal and of the seventh nerve is destroyed (2). The horizontal semicircular canal (3) has been perforated by the carious process, and the median wall of the mastoid antrum (4) is roughened. The pus entered the labyrinth through the openings in the promontory, and made its way through the internal auditory meatus to the cranial cavity.

Fig. 4. Chronic Suppurative Otitis Media; Caries of the Petrous Portion (Carotid Canal); Fatal Hemorrhage. The carotid has been drawn out of its canal. Petrous portion of the right temporal bone from a phthisical patient thirty-two years of age. The promontory (1) is completely undermined by granulation tissue; the vestibule and the superior and external ampullæ (2) are perforated. The carotid canal (3) immediately above its lower extremity contains an opening (4) 3 mm. in length and 1.5 mm. in height; the corresponding spot on the carotid artery presents a similar defect that is surrounded by a wall of granulation tissue (5).