Louis S. Hansen

Proliferative verrucous leukoplakia: A long-term study of thirty patients

Up to 6% of oral leukoplakia, a relatively common mucosal disease, can be expected to become malignant. This report describes a long-term study of 30 patients in whom a particular form of leukoplakia was identified and labeled proliferative verrucous leukoplakia (PVL), a disease of unknown origin, which exhibits a strong tendency to develop areas of carcinoma. PVL begins as a simple hyperkeratosis but tends to spread and become multifocal. PVL is slow-growing, persistent, and irreversible, and in time areas become exophytic, wartlike, and apparently resistant to all forms of therapy as recurrence is the rule. The disease was most commonly seen in elderly women and had been present for many years. Patients were followed for 1 to 20 years. Thirteen died of or with their disease, 14 were alive with PVL, and 3 were alive without PVL at last contact. PVL rarely regressed despite therapy. All patients who died had persistent or recurrent disease. PVL appears to constitute a continuum of hyperkeratotic disease, ranging from a simple hyperkeratosis at one end to invasive squamous cell carcinoma at the other. Microscopic findings are dependent upon the stage of the diseases development and the location and adequacy of the biopsy.

Ameloblastomas with pronounced desmoplasia

Ameloblastomas are uncommon epithelial tumors of the jaws comprising approximately 1% of all odontogenic cysts and tumors.’ Although most are microscopically benign and lack cytologic atypia, they are generally considered to be locally aggressive and destructive, exhibiting a high rate of recurrence. In spite of its apparent rarity, several large series describing a thorough clinical statistical analysis have been reported.‘,2 Over 80% of all ameloblastomas occur in the mandible, the vast majority being located in the molar-ramus region. The average age of patients is approximately 39 years, and there is essentially no sex prediliction. Radiographically, the ameloblastoma may vary in size and configuration from a small, well-circumscribed unilocular radiolucency to a large multilocular radiolucency. Many are associated with unerupted teeth and resemble dentigerous cysts. The most common clinical finding is a nontender enlargement that, in spite of a relatively slow rate of growth, may reach enormous size.3 Microscopically, the classic ameloblastoma consists of islands, nests, and cords of odontogenic epithelium rimmed by columnar cells resembling ameloblasts. The center of these epithelial structures contains loosely arranged spindleor stellateshaped cells resembling the stellate reticulum of a developing tooth. The surrounding fibrous connective tissue stroma is composed of mature collagen.

Pigmented nevi of the oral mucosa: A clinicopathologic study of 36 new cases and review of 155 cases from the literature

Review and analysis of data on 191 cases of oral pigmented nevi from the literature and from two studies at the University of California, San Francisco, revealed that nevi of the intramucosal type are the most common, followed by the common blue nevus. Compound and junctional nevi are rare, and combined nevi are the rarest. The data on location, presence of clinical pigmentation, configuration, size, and duration of the nevi, as well as on the patients age, sex, and race, are analyzed. Blue nevi were found mostly on the hard palate, whereas intramucosal nevi occurred on the buccal mucosa, on the gingiva, and on the lips as well as on the palate. Nonpigmented nevi were especially common (22%) in the intramucosal group. Most oral nevi are raised, which can be of help in the differential diagnosis. Oral nevi are small, most being between 0.1 and 0.6 cm at the largest dimension. Because the malignant potential of oral nevi is still uncertain and because preexisting macular pigmentation is present in about one third of all patients with oral melanoma, it is advisable to accurately diagnose all oral pigmented lesions, many of which will require microscopic examination.

Amalgam pigmentation (amalgam tattoo) of the oral mucosa. A clinicopathologic study of 268 cases.

Abstract A series of 268 cases of amalgam tattoo is analyzed both clinically and histologically. The most common location was the gingiva and alveolar mucosa, followed by the buccal mucosa. Histologically, the amalgam was present in the tissues as discrete, fine, dark granules and as irregular solid fragments. The dark granules were arranged mainly along collagen bundles and around blood vessels. They were also associated with the walls of blood vessels, nerve sheaths, elastic fibers, basement membranes of mucosal epithelium, striated muscle fibers, and acini of minor salivary glands. Dark granules were also present intracellularly within macrophages, multinucleated giant cells, endothelial cells, and fibroblasts. Although in 45 percent of the cases there was no tissue reaction to the amalgam, in 17 percent there was a macrophagic reaction and in 38 percent there was a chronic inflammatory response, usually in the form of a foreign body granuloma, with multinucleated giant cells of the foreign body and Langhans types. Asteroid bodies were also found in some of the foreign body giant cells.

Choristomas of the oral cavity: A review

The choristoma is a tumorlike mass of normal cells in an abnormal location. Intraoral choristomas have been reported under a wide variety of names. This comprehensive review of the English-language literature on oral choristomas offers a classification of these lesions, analyzes their clinical and histologic features, and discusses possible pathogeneses and treatment.

The histomorphologic spectrum of peripheral ossifying fibroma

A series of 207 cases of peripheral ossifying fibroma was analyzed both clinically and histologically. Almost 60% of the lesions occurred in the maxilla, and in both jaws more than 50% occurred in the incisor-cuspid region. The lesion was most common in the second decade. Females were affected more frequently than males; the ratio was 1.7:1. The recurrence rate--16%--was relatively high. Histologically, in 66% of the cases the surface epithelium was ulcerated and in the remainder it was intact. The ulcerated lesions were composed of highly cellular fibroblastic connective tissue, whereas in the nonulcerated lesions part of the tissue was more collagenized. Both types contained mineralized products in the form of bone, cementum-like material, and/or a dystrophic type of calcification. The dystrophic calcification was most prevalent in the ulcerated lesions. The mean duration at time of excision for the ulcerated lesions was 5.6 months and for the nonulcerated lesions was 24 months. It is proposed that the ulcerated and nonulcerated lesions represent a spectrum of one lesion with different stages of maturation.

Traumatic bone cysts of jaws.

Abstract The findings in a clinicopathologic study of sixty-six previously unreported cases of traumatic bone cysts are presented and compared with the findings in more than 150 previously reported cases. Most of the patients were between 11 and 20 years of age, and there was no difference in the incidence of the lesion between the sexes. Most patients were asymptomatic, although a significant number of them had symptoms and/or bony expansion. Vitality of teeth was not related to etiology or pathogenesis. In some cases the radiographic findings suggested a traumatic bone cyst, but surgical exploration was essential for definitive diagnosis. The lesion occurs in the maxilla more often than previously reported, although the mandible is still the most common location. The etiology and pathogenesis of the traumatic bone cyst remain unknown. Although the possibility that trauma plays a role in some cases cannot be excluded, present evidence is far from convincing.

Variations in keratinizing odontogenic cysts and tumors

Classification of keratinizing odontogenic cysts and tumors is not entirely satisfactory to the clinician and pathologist because many individual cases do not fit precisely into a particular category. This report describes the nature of some of these marginal lesions in order that similar cases may be diagnosed and treated correctly. Eight selected cases are described histologically, and their clinical behavior is discussed. It is concluded that the histopathologic appearance of the odontogenic epithelium in odontogenic cysts and tumors varies to a large extent and gives rise to a variety of keratinizing lesions. It is further concluded that some varieties are unique and, for the present, treatment of the rare lesions depends more on observed clinical behavior, with morphology having a lesser role in prognosis. It is important that clinicians as well as pathologists be aware of the wide variation of these keratinizing lesions so that the patient will receive optimum treatment.

A comparison of carbon dioxide laser, liquid nitrogen cryosurgery, and scalpel wounds in healing

With the carbon dioxide surgical laser, the liquid nitrogen cryoprobe, and the scalpel, wounds were created on the shaved abdomen of 24 rats, and the patterns of healing were studied. The laser wounds were the first to epithelialize, followed by the scalpel wounds, with the cryosurgery wounds the slowest to epithelialize. The results were confirmed histologically.

Necrotizing sialometaplasia. The relationship of its pathogenesis to its clinical characteristics.

abstract The clinical and histological characteristics of 7 new cases of necrotizing sialometaplasia are described. The pathogenesis of these unusual lesions are discussed, especially in relation to the various clinical manifestations.