Russell L. Corio

Acinic cell adenocarcinoma. A clinicopathologic analysis of 294 cases

Two hundred and ninety‐four cases of acinic cell adenocarcinoma were reviewed for the purpose of defining the clinical parameters and determining the distribution of the four histomorphologic tissue patterns and five cell types for correlation to biologic behavior. The vast majority occurred in the parotid gland. There was a male predominance and a peak incidence in the third decade of life. The tumors were usually less than 3 cm in diameter and were slow growing. Pain was a common symptom, but was not indicative of prognosis. Nearly one half of the neoplasms exhibited multiple tissue growth patterns, and three fourths of the tumors displayed more than one cell type. The microcystic pattern was seen most frequently, regardless of the biological behavior of the tumors. The well‐differentiated acinic cell was the most prevalent cell type except in cases with metastases, where the intercalatedduct cell type was slightly more frequent. Follow‐up of 244 cases revealed a recurrence rate of 12%, a metastatic rate of 7.8%, and death rate of 6.1%. Since all histomorphologic patterns and cell types were manifest in tumors which recurred, metastasized, or caused the death of the patients, it seems appropriate to consider these neoplasms as low‐grade adenocarcinomas rather than essentially benign with occasional unpredictable malignant behavior.

Epithelial-myoepithelial Carcinoma of intercalated duct origin

A clinicopathologic and ultrastructural analysis of sixteen cases of epithelial-myoepithelial carcinoma of intercalated duct origin was undertaken, together with a review and correlation of eight previously reported cases. The neoplasm is found predominantly in women, with the majority occurring in the seventh and eighth decades of life. Most of these tumors occurred in the parotid gland. Five patients had one or more recurrences, and one patient died of tumor. Histologically, these tumors are composed of two cell types, generally exhibiting a glandular or ductlike arrangement. Ultrastructural findings confirm the duality of the cell population.

Squamous odontogenic tumor. Report of six cases of a previously undescribed lesion.

Six cases of a previously unnamed oral lesion are described and the name squamous odontogenic tumor is applied. The lesion causes radiolucent areas of bone destruction adjacent to the roots of teeth. In one case there were multiple separate lesions. Light microscopy revealed numerous islands of benign squamous epithelium with focal areas of keratinization and calcification. Electron microscope examination in one case showed normal squamous epithelial cells with abundant glycogen granules, tonofilaments and myelin bodies. Complete surgical excision seems the best therapy, as only one lesion recurred following treatment.

Small cell carcinoma of the major salivary glands

Small cell carcinoma is primarily a pulmonary neoplasm that rarely arises in extrapulmonic sites including salivary glands of the head and neck. Twelve cases of small cell carcinoma of salivary gland origin were retrieved from the Armed Forces Institute of Pathology files. Six tumors occurred in the parotid gland and six in the submandibular gland. Tumors were classified into two categories: those with areas of histologically typical small cell carcinoma (7 cases) and those with areas of typical small cell carcinoma with foci of ductal differentiation (5 cases). Follow‐up information was available in all 12 cases. Electron microscopy was done on eight tumors; only one demonstrated round electron dense intracytoplasmic neurosecretory granules. These observations further support evidence in the literature suggesting most of the small cell carcinomas of salivary gland origin are not true neuroendocrine (“oat cell”) carcinomas, but actually are small cell ductal carcinomas. These tumors appear to have a better prognosis than small cell carcinoma of the lung or nonsalivary gland sites in the head and neck region, with an estimated 2‐and 5‐year survival of 70 and 46%, respectively. Cancer 58:705‐714, 1986.

Plexiform unicystic ameloblastoma. A variant of ameloblastoma with a low-recurrence rate after enucleation.

The term, plexiform unicystic ameloblastoma, refers to a pattern of epithelial proliferation that has been described in dentigerous cysts, primarily in persons in the second and third decades of life and predominantly in the posterior part of the mandible. This article provides the first study on the biologic behavior of these lesions. Of 28 examples treated by enucleation/curettage, and for which adequate follow‐up information was obtained, only three recurred. This figure (10.7%) compares very favorably with the 55% to 90% recurrence rate quoted for ameloblastomas of all types that have been treated by curettage and is similar to that found in other types of unicystic ameloblastoma. The plexiform unicystic ameloblastoma is concluded from this study to be an undifferentiated histologic variant of unicystic ameloblastoma and not a separate entity. Enucleation with long‐term follow‐up information is adequate for tumors that have proliferated into the lumen of the cyst, but more extensive surgery is recommended for those that involve the periphery of its fibrous connective wall. This study has also shown that plexiform unicystic ameloblastomas are not always associated with unerupted teeth, in which case they probably occur over a wider age range than those resembling dentigerous cysts.

Spindle cell carcinoma of the oral cavity: A clinicopathologic assessment of fifty-nine cases

The clinical features, histomorphologic characteristics, therapeutic results, and follow-up data for fifty-nine cases of spindle cell carcinoma of the oral cavity were analyzed. Circumstantial evidence favors a pathogenesis from metaplastic malignant epithelial cells for the spindle cell proliferation. These neoplasms occurred most frequently on the lower lip, tongue, and alveolar ridge in either polypoid, exophytic, or endophytic configurations. A male predominance was attributed to a military and veteran bias. Mean age at occurrence was 51 years for men and 67 years for women. Symptoms were infrequently reported. Histomorphologically, fasciculated, myxomatous, and streaming patterns of the spindle cells were observed, with variable mitotic activity, pleomorphism, benign and atypical giant cells, inflammation, vascularity, and infiltration. Follow-up data on forty-five patients revealed that only fourteen were alive and well, whereas twenty-five were dead of their disease. Mean survival time for those dead of the disease was under 2 years. Five-year survival was a significant indicator of cure. No clinical or histomorphologic characteristic other than distant metastasis was found to be a reliable prognostic indicator. Wide surgical excision, alone or with radical neck dissection, was the most successful therapeutic modality. Radiation was ineffective.

Sarcomas and sarcomatoid neoplasms of the major salivary gland regions. A clinicopathologic and immunohistochemical study of 67 cases and review of the literature.

Sixty‐seven cases of sarcomas and sarcomatoid neoplasms of the major salivary gland regions were studied in order to determine the clinical and histomorphologic features and biologic behavior. Fifty‐seven of these proved to be sarcomas and the two most common types were malignant schwannoma (11) and fibrosarcoma (9). Nine sarcomas could not be subclassified morphologically. Ten cases, originally believed to be sarcomas, proved by means of immunohistochemistry to be either carcinomas (five cases) or melanomas (five cases). Fifty‐nine of the 67 cases occurred in the parotid gland regions, and the remaining eight occurred in the submandibular regions. Twenty of the 67 cases were thought to arise from within the gland, nine from paraglandular tissues, and insufficient data was present to anatomically categorize the other 38 cases. The mean age of occurrence was 42 years for men and 38 years for women. A swelling was the presenting symptom in 64 cases, with a mean duration of 4.3 months. Pain, tenderness, or paralysis were noted in 17 cases, but the swelling was painless in seven cases. Follow‐up data of 42 sarcoma patients revealed that 17 experienced recurrences, 16 developed metastases, and 15 died of disease. These rates were lowest among patients with tumors arising from within the gland (Group I) and highest among those patients with tumors of paraglandular origin (Group III). Mean survival time for those dying of disease was 2.4 years, and a 5‐year survival time appeared to be a significant indicator of cure. The most successful therapy was either parotidectomy (superficial or total) or a combination of surgery and radiation. The morphologic and the immunohistochemical evidence suggest that the majority of the tumors represent true sarcomas that may arise from undifferentiated pluripotential cells, but that the remainder (15%) represent epithelial malignancies.

The relationship of plexiform unicystic ameloblastoma to conventional ameloblastoma

The term plexiform unicystic ameloblastoma refers to a pattern of epithelial proliferation that has been described in cystic lesions of the jaws. It has been considered hyperplastic epithelium, rather than ameloblastoma, by some pathologists because it does not exhibit previously accepted histologic criteria for ameloblastoma. This article provides histologic evidence that plexiform unicystic ameloblastoma is, in fact, a variant of conventional unicystic ameloblastoma by reporting ten cases of unicystic ameloblastoma that exhibit both patterns. Further evidence of the ameloblastomatous nature of plexiform unicystic ameloblastomas is that their biologic behavior, even when this pattern occurs alone, is similar to that of conventional unicystic ameloblastoma.

The oral melanotic macule.

A clinical and histologic study of eighty oral melanotic lesions which do not readily fit into recognized categories of melanotic lesions was conducted. These lesions tend to occur in the fifth decade of life and are most frequently seen on the gingiva, with the buccal mucosa and palate the next most frequent sites. The lesions are usually single, smaller than 1 cm., but they may also occur as multiple lesions. There is no sex bias, and there seems to be a number of etiologic factors. In a few cases long-term follow-up was possible. There is no indication of a tendency toward recurrence or development of malignant lesions. Histologically, none of the lesions shows atypia. Melanin pigmentation tends to be present in significant amounts in the basal-cell layer and less often in the lamina propria. There are no outstanding histologic differences among the eighty specimens. It is suggested that the term oral melanotic macule be used for these lesions, unless a specific cause can be confirmed by clinical data. Although these lesions should not be considered premalignant, it would be prudent to remove them for histologic confirmation of clinical impressions.

The labial melanotic macule

Fifty-five cases of a melanotic lesion of the lips which is well known, but not well described, are reported. The lesions characteristically occur on the lower lips of young adults. Males and females are equally affected. These lesions may be ephelides, postinflammatory melanoses, or unique lesions for which there is no exact cutaneous counterpart. We suggest the term labial melanotic macule as a descriptive one which would encompass the three different constituent entities. On the basis of follow-up information obtained and the histopathologic character of the lesions, this entity is benign and does not, in our opinion, have any malignant potential.