Leiomyoma of the External Auditory Canal.

Angioleiomyomas (ALMAs) are benign tumors that arise from smooth muscle cells that form the tunica media of vascular structures. To our knowledge, only five cases of ALMA of the external auditory canal (EAC) have been reported. We report the case of a 52-year-old man with left otalgia, otorrhea, auricular fullness, and hearing loss. On otomicroscopic examination, a reddish and smooth mass completely occluding the EAC was seen. Computed tomography scan showed a soft tissue mass with a complete opacification of the left EAC. A possible diagnosis of ALMA should be considered when finding a tumor inside the external ear canal. An accurate pathological examination should be performed to differentiate benign vascular ALMA from malignant leiomyosarcomas. Complete surgical excision is the treatment of choice in benign tumors.

Human ceruminous gland: ultrastructure and histochemical analysis of antimicrobial and cytoskeletal components.

The ceruminous glands in the skin of the human external auditory canal are modified apocrine glands, which, together with sebaceous glands, produce the cerumen, the ear wax. Cerumen plays an important role in the protection of the ear canal against physical damage and microbial invasion. We studied the morphology of the glandular cells by light and electronmicroscopy. Antimicrobial and cytoskeletal components of the ceruminous glands were investigated by immunohistochemical methods. Numerous antimicrobial proteins and peptides are present in the ceruminous glandular cells: beta-defensin-1, beta-defensin-2, cathelicidin, lysozyme, lactoferrin, MUC1, secretory component of IgA. These data indicate a crucial role in the innate host defense against diverse pathogens. The apocrine secretion mechanism is a special mode of secretion by which the apical part of the cell cytoplasm surrounded by a membrane is pinched off. We could show that the presence of actin filaments, CK 19 and CK 7, seems to play a role in the pinching-off mechanism. Finally, we showed the secretion of lipid vesicles from the ceruminous gland. We could extend the number of detected antimicrobial peptides and proteins in human ceruminous glandular cells that protect the surface of the external auditory meatus. In addition, we detected proteins involved in the apocrine secretion mode of the ceruminous gland.

Argyrophilic nucleolar organizer regions in auditory meatal skin and middle ear cholesteatoma.

Comparative silver-staining of argyrophilic nuclear organizer regions (AgNORs) was performed to study the proliferative activity of auditory meatal skin and middle ear cholesteatoma. AgNOR expression patterns were counted by standardized methods in two centres, Bochum and London, and mean numbers of dots per nucleus were calculated. Specimens of normal auditory meatal skin showed 1.54 dots/nucleus (n = 12) in the Bochum study, whereas cholesteatoma had 3.71 dots/nucleus (n = 21). In the London study normal meatal skin showed two dots/nucleus (n = 4), whereas acquired cholesteatoma (n = 8) gave a mean of 4.90 dots/nucleus and congenital cholesteatoma a mean of 4.70 dots/nucleus (n = 2). Our findings confirm the hyperproliferative state of middle ear cholesteatoma, suggest that the congenital variety of cholesteatoma may have a similar activity and indicate that AgNOR staining is a useful technique for assessing cellular proliferation in cholesteatoma and objectifying and quantifying its aggressive behaviour.

Monostotic fibrous dysplasia of the temporal bone with associated lymphadenopathy.

Fibrous dysplasia of the temporal bone is a very unusual condition and its association with an abnormal lymph node has not been previously reported. Although it is benign condition causing conductive deafness, cholesteatoma may develop insidiously as illustrated by this case. We recommend regular long term follow up and surgical exploration if a changing clinical picture suggests the possibility of complications.

Pleomorphic adenoma of the external auditory canal. An immunohistochemical and ultrastructural study.

Primary tumors arising from the glandular structures of the external auditory canal (EAC) are rare, with the majority arising from the ceruminous glands. The histochemical, immunohistochemical, and electron microscopic features of a pleomorphic adenoma of the EAC are presented; this is the seventh case reported. These studies confirm the key role of the myoepithelial cell in this tumor and include a correlation with pleomorphic adenomas in other sites.

Neurothekeoma (peripheral nerve sheath myxoma) of the external auditory canal.

A patient who presented with an isolated soft-tissue tumor in the lateral portion of the external auditory canal, which after removal was diagnosed histopathologically as a peripheral nerve sheath neurothekeoma, is presented. Peripheral nerve sheath myxomas (neurothekeomas or perineural myxomas) have been reported to occur on the central area of the face, arms and shoulders. This is the first case in which a tumor of this type has been reported to develop in the external auditory canal. The distinguishing histopathological characteristics and the differential diagnosis of this tumor are discussed.

The formation of ultrastructural epithelial and subepithelial connective tissue changes in experimentally induced cholesteatomas in guinea pigs.

Histoacryl-induced cholesteatomas were produced in guinea pigs at the posterosuperior part of the external ear canal adjacent to the tympanic membrane. Semithin and ultrathin tissue sections were used to study primary formation of the cholesteatoma as well as the influence of the altered epithelium upon the bordering zone of connective tissue. Quantitative and qualitative tissue changes were analyzed by electron microscopy and showed degradation and new formation of collagen and activation of fibroblasts. Our findings are similar to those previously reported on human cholesteatomas and indicate that the bordering subepithelial tissue seems to be influenced through the basilar membrane.

Osteomas and exostoses of the external auditory canal - medical and surgical management.

Osteomas and exostoses have distinct clinical and histopathologic features. Osteomas are usually solitary, pedunculated, bony growths attached to the tympanosquamous or tympanomastoid suture line, characterized histologically by an internal structure of abundant discrete fibrovascular channels surrounded by irregularly oriented lamellated bone. Exostoses are usually multiple, bilaterally symmetrical, broad based elevations of bone involving the tympanic bone. They are histologically characterized by parallel, concentric layers of subperiosteal bone. The infrequent symptoms resulting from these lesions can usually be managed medically; however, on occasion surgical removal is indicated. While surgical removal of the osteoma is usually possible via the external auditory meatus, we recommend that an exostosis be removed utilizing a postauricular approach.

Secretory mechanisms of human ceruminous glands: a transmission and scanning electron microscopic study.

Two secretory mechanisms (eccrine and apocrine) were observed by transmission and scanning electron microscopy in the same secretory cells of the human ceruminous glands. The eccrine secretion occurs as a typical exocytosis by fusion of the limiting membrane of the secretory granule with the apical plasmalemma. The apocrine secretion is more complex and takes place by sequential steps: bulging of the cellular apex into the lumen, constriction of the projection, and detachment of it from the cell. This mechanism generally causes the removal of the entire projection all at once by decapitation at its base; some variations of this process have been found, however, and are described in the present work. A double membrane, apparently separating the apical protrusion from the rest of the cell, is noticeable in our photographs. Nevertheless, even if this membrane is very similar to a demarcation layer, we consider it as an intercellular double membrane separating two obliquely sectioned cells.

Osteomas and exostoses of the external auditory canal. A clinical, histopathologic and scanning electron microscopic study.

Osteomas of the external auditory canal are considered clinically to be discrete, pedunculated bone lesions arising along the tympanosquamous suture. They are benign lesions but often are slowly progressive in size. Exostoses of the external auditory canal are broad-based elevations of bone usually multiple and bilaterally symmetric, involving the tympanic bone. It appears that both clinical and histopathologic evidence is sufficient to justify the impression that these two lesions should be considered separate entities and clinical diagnostic and histopathologic criteria have been suggested for diagnosis of these lesions.

Transmission and scanning electron microscopy of the human ceruminous apocrine gland. II. Myoepithelial cells.

The myoepithelial cells of the human ceruminous apocrine gland were observed with transmission and scanning electron microscopes. The myoepithelial cells are long fibrous cells about 100-150 mum in length and 3-5 mum in width. They are arranged in parallel with each other, and their long axes are parallel to that of the secretory tubule itself. The tips of cells are often sharply pointed and their lateral tapering surface may be contiguous with adjacent cells forming a side-by-side contact, while other cells may have a blunt tip which is conjuncted with a similar tip of the next cell forming an end-to-end junction. The myoepithelial cells are joined to each other by desmosomes and there are also desmosomes at their junction with secretory cells. The outer surface of the cell abutting on the basal lamina has some exaggerated densities which are undoubtedly identical to the hemidesmosomes of epidermal cells. There are well developed foldings in the plasma membrane of the secretory cells, but the surface of the myoepithelial cells has very few foldings and projections. The relative shortage of intercellular attachment devices between the secretory and myeopithelial cells makes it easy to peel off the secretory cells to disclose the myoepithelium, a useful feature of scanning electron microscopy. The nucleus-containing part of the cell protrudes slightly upward and invades the secretory epithelium. The cytoplasmic rim surrounding the nucleus contains a small Golgi apparatus and some other organelles. The cytoplasm of the basal half of the cell contains closely packed myofilaments running parallel to the long axis of the cell. There is no definite arrangement of thin and thick myofilaments. Microtubules which often occur in pairs are arranged parallel to the myofilaments.

[Morphology and clinical significance of syringomas of the external auditory canal (author's transl)]. / Morphologie und klinische Wertigkeit der Gehörgangs-syringome

Syringomas of the external auditory canal ("ceruminomas"), are very rare their morphology is varied and their clinical course hardly predictable. Their nomenclature is controversial and easily misunderstood. Two cases of syringomas of the external auditory canal are reported (one adenoma and one adenoid-cystic carcinoma) which were also studied by means of electron microscopy. The morphology and clinical significance of these tumors is discussed.