Henrik B. Hellquist MD, PhD, SAPath(Stockh), FCAP’s research while affiliated with Haukeland University Hospital and other places

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Publications (43)


The Normal Ear
  • Chapter

January 2001

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14 Reads

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Henrik B. Hellquist MD, PhD, SAPath(Stockh), FCAP

The ear is not a single organ, but two, being the peripheral receptor site both for stimuli derived from sound waves and for changes of posture. The structures subserving both of those functions are developed from an invagination of ectoderm early in embryonic life — the otocyst — to produce the epithelia of the membranous labyrinth of the inner ear. Superimposed upon, and developing slightly later, the first and second branchial arch systems provide structures which augment the hearing function. The endodermal component of the first branchial system, the branchial pouch, gives rise to the Eustachian tube and middle ear epithelia and the corresponding ectodermal outgrowth, the first branchial cleft, to the external ear epithelia. The connective tissue part of the local branchial system, the first and second branchial arches, produces the ossicles. The eighth cranial nerve outflow from the central nervous system grows to link up with the sensory epithelia lining the otocyst-derived cochlear and vestibular labyrinths and the cartilaginous, bony and muscular conformations of the ear are developed from the mesenchyme surrounding these early epithelia.



The Normal Nose and Paranasal Sinuses

January 2001

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19 Reads

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1 Citation

The development of the inner structure of the nose and paranasal sinuses is initiated by the formation in the second month of an ectodermal thickening, the olfactory placode, on each side. These are each placed above and medial to a maxillary swelling, which has been formed above a mandibular swelling, the four swellings, two maxillary and two mandibular (the latter of which soon fuse to form the lower jaw) being arranged around a primordial mouth cleft. Medial to each olfactory placode a swelling is formed, the medial nasal fold. The fusion of the two medial nasal folds gives rise to the frontonasal process, a precursor of the external nose and nasal septum. Lateral to each olfactory placode, a lateral nasal process on each side forms the groove between the nose and the eye. The groove between the maxillary process and the lateral nasal fold on each side gives rise to the nasolacrimal duct. The olfactory placode forms a pit, which sinks deeper and eventually joins posteriorly with the oral cavity. The pit of the nasal cavity produces ledges on its lateral wall, which are each eventually supported by a bony skeleton to produce the turbinates. Paranasal sinuses bud off the main nasal cavity (Fig. 12.1).


Bony Abnormalities

January 2001

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784 Reads

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1 Citation

Pagef’s disease (osteitis deformans) is a common condition affecting particularly the skull, pelvis, vertebral column and femur in people over 40 years of age. The cause is not yet certain, but the presence in many cases of paramyxovirus-like structures seen within osteoclasts has prompted the suggestion that Pagefs disease may be of viral aetiology and the measles virus and canine distemper viruses have been under scrutiny as candidates. The pathological change is one of active bone formation proceeding alongside active bone destruction. The affected bones are enlarged, porous and deformed. Microscopically, bone formation is seen in trabeculae of bone with a lining of numerous osteoblasts. A mosaic appearance is formed by the frequent successive deposition of bone, cessation of deposition resulting in thin, blue “cement lines”, followed again by resumption of deposition and its cessation, and so production of further cement lines. Bone destruction is shown by the presence of numerous, large osteoclastic giant cells with Howship’s lacunae. Areas of chronic inflammatory exudate intermixed with the bone are common (Fig. 10.1).


Neoplasms of Fibrous Tissue

January 2001

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11 Reads

It is doubtful whether a lesion composed entirely of adult fibrous tissue with collagen and sparse fibrocytes is ever neoplastic; it is usually the endresult of an inflammatory process. Occasionally a fibroblastic form of meningioma may be so poorly cellular as to resemble a fibrous tumour. In such cases the concentrically laminated arrangement of the fibrous tissue may be the only diagnostic feature of meningioma (see Chapter 18). Post-inflammatory fibrous tissue in the nose likewise may present such an arrangement, so it is necessary to search a wider area of the lesion for the presence of more diagnostic cellular whorls of meningioma.


Neoplasms of the External Ear

January 2001

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10 Reads

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2 Citations

The external ear is a specialised appendage of the skin, so that its neoplasms are most frequently those derived from skin. Bony neoplasms also occur, as would be expected from the presence of bone nearby, but the cartilage of the ear seems to have no neoplastic propensity. The following account will deal only with those tumours that have a predilection for that region and those that pose special diagnostic histological and clinical problems.


Papilloma

January 2001

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3 Reads

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1 Citation

In the vestibule and nostril, papillomas are usually stratified squamous arising on the skin surface. Rarely do they recur after simple removal, and malignant transformation is seldom a problem. Abnormal hyperplastic changes of the epithelium are frequent, but if similar criteria of assessment for possible cancerous or precancerous change are used to those applied in other stratified squamous epithelia (see Chapter 34), a diagnosis of malignancy will be unusual.


Squamous Cell Papilloma

January 2001

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9 Reads

Squamous cell papillomas are frequent in the larynx of adults. They also found in children where, because of the much narrower diameter of the airway, the more widespread involvement in the larynx and the greater tendency to recurrence, the symptoms are more serious, and treatment is more urgent and difficult. It is thus customary to divide the condition on the basis of the age of the patient into juvenile and adult types. In some juvenile cases the papillomas persist into adult life. The pathological changes are similar at all ages, and will be described first before a discussion of the natural history of the lesion.




Citations (3)


... At the pyriform fossa, lymphocytes located immediately beneath the epithelium occasionally form lymphoid follicles with rich lymphatic vessel plexus. The submucosa contains glands made up of both mucous and serous acini that open on the surface by occasional ducts [1]. ...

Reference:

Internal Hypopharyngeal Cyst: A Review of Literature
Hypopharynx: Anatomy, Histology and Pathology
  • Citing Chapter
  • January 2001

... Exostosis are multiple, bilateral, appear as wide based and smooth lesions of the EAC and are usually considered to be a reactive condition secondary to multiple cold-water immersions or recurrent otitis externa. 9,10 There are limited histopathological studies done for osteoma and exostosis as these lesions are drilled during surgical removal. Exostosis are concentric, dense layers of subperiosteal bone with abundant osteocytes, lacking fibrovascular channels covered with periosteum and squamous epithelium. 1 Studies by Fenton et al suggested that fibrovascular pathway is a characteristic feature of osteoma, and could also be found in exostosis also and so it could not be differentiated histopathologically. 2 In some cases they might also occur together. ...

Neoplasms of the External Ear
  • Citing Chapter
  • January 2001

... The subepithelial tissue in both the NAM and PSM consisted of loose connective tissue containing blood vessels and glands of varying sizes and numbers. Different authors describe an increased vascularization of the nasal mucosa compared to the paranasal sinuses mucosa in general [40,[44][45][46]. Large veins in the nasal cavity have a high capacity for blood accumulation, which can lead to a severe swelling of the nasal mucosa [45,46]. ...

The Normal Nose and Paranasal Sinuses
  • Citing Chapter
  • January 2001