Lymphoid and epithelial markers in small cell anaplastic thyroid tumours

Small cell carcinoma of the head and neck: a review

Small cell carcinoma (SCC) has become recognized as a distinct, though relatively infrequent, clinical pathology that occurs in multiple sites throughout the head and neck. Excluding cases that are considered to arise from skin, SCC in the head and neck has been found to develop in nearly all structures associated with the upper aerodigestive tract. Among the head and neck sites, the frequency of SCC is greatest in the larynx, with salivary glands and the sinonasal region comprising the other principle areas of origin. Controversy exist as to whether SCC can develop as a distinct entity in the thyroid, with most tumors that previously would have been considered as SCC now found to be lymphomas or variant forms of other types of thyroid malignancy. While there seems to be some differences among tumors arising from the various subsites, in general all SCC that originate in the head and neck have a tendency for aggressive local invasion and a strong propensity for both regional and distant metastasis. Treatment may include surgical resection, radiotherapy, chemotherapy, or some combination of these modalities. Due to the infrequency of these tumors, it is very unlikely that any large, controlled study will ever be done. For this reason, recommendations for treatment of SCC arising in the head and neck are based primarily on retrospective data from various small case series and on comparative data for treatment of SCC of bronchogenic and other extrapulmonary origin. Although patients with truly limited local disease may enjoy some prolonged survival, most patients with this tumor do poorly despite all current attempts at treatment.

Prognostic and predictive factors in endocrine tumours

This review encompasses the diagnostic features of malignancy, the routinely observable prognostic features and the prognostic and predictive features emerging from research techniques in the principal endocrine neoplasms: pancreatic and extrapancreatic endocrine cell tumours, thyroid and parathyroid neoplasia, adrenal cortical neoplasms and adrenal and extra-adrenal paragangliomas. While each endocrine tissue has its own set of diagnostic features for malignancy, and prognostic features once a diagnosis of malignancy has been established, there are a few common themes. For several endocrine neoplasms, definite recognition of malignancy can be difficult and may depend upon frank invasive or metastatic growth at presentation. Endocrine tissues are dynamic, with hyperplastic and regressive phenomena, some of which may mimic malignancy. Even when unequivocal features of malignancy are available for observation, their distribution in tissue may be very focal, necessitating thorough sampling. The accurate documentation of routinely observable histological features interpreted in the light of current literature has not been superseded by special techniques in the statement of diagnosis or prognosis in the vast majority of endocrine neoplasms.

Extranodal lymphomas of the head and neck

Malignant lymphomas represent approximately 5% of all malignant neoplasms of the head and neck and may involve nodal or extranodal sites. Nodal head and neck lymphomas are similar to other nodal sites and are not further reviewed here. The head and neck region is the second most frequent anatomical site of extranodal lymphomas (after the gastrointestinal tract). Most are non-Hodgkin's lymphomas of B-cell lineage, and overall diffuse large B-cell lymphoma is the most common type. Hodgkin's lymphoma rarely occurs in extranodal sites. Other hematologic neoplasms that commonly involve extranodal sites of the head and neck are also discussed. In this review, we begin by discussing lymphomas involving the head and neck according to anatomical site. Then we discuss specifically the pathological findings of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue, plasmablastic lymphoma, extramedullary plasmacytoma, and extranodal natural killer/T-cell lymphoma of nasal type.

Malignant lymphoma with myxoid stroma: a new pattern in need of recognition

We report a case of malignant lymphoma in the soft tissues exhibiting prominent myxoid stromal changes and cord-like cellular arrangement, mimicking the architectural as well as cytological features of myxoid chondrosarcoma, except for the absence of tumour lobulation. The only clue to the possible lymphomatous nature of the lesion was the past history of lymphoma. Immunohistochemical studies showed that this represented a B-cell lymphoma, staining positively for leucocyte common antigen and five B-lineage markers L26, MB2, B1 (CD20), B4 (CD19) and To15 (CD22). We conclude that malignant lymphoma should not be excluded from consideration when one encounters a myxoid tumour.

The biological characteristics and chemosensitivity of anaplastic thyroid carcinoma transplanted into nude mice

Three xenografts established from three patients with anaplastic thyroid carcinoma were investigated for their biological characteristics and chemosensitivity. The histological and immunohistochemical findings of these tumors were almost the same as those of the original tumors. Although the growth rate of each xenograft was constant, the tumor doubling time varied from 4.8 per 9.0 days, and the labeling indexes, determined using bromodeoxyuridine pulse labeling, varied from 11.4 to 25.1 per cent. The chemosensitivity tests were performed according to the Battelle Columbus Laboratories Protocol, with adriamycin, cyclophosphamide, cisplatin, mitomycin C and tegafur administered intraperitoneally to tumor-bearing nude mice in maximum tolerable doses. Tumors with slower growth rates tended to be sensitive to more drugs. Furthermore, cyclophosphamide showed antitumor effects against all the tumors tested. Although previous treatments of the original tumors may have affected the results, our results suggest that a more suitable chemotherapy for anaplastic thyroid carcinoma could be developed.

The WHO histological classification of thyroid tumors: a commentary on the second edition

This article introduces the revised WHO classification of thyroid tumors, giving an account of the major changes made and the reasons behind the changes, as well as listing the actual classification now recommended. It is intended to draw general attention to the revision, the full version of which will be published separately.

Primary thyroid thymoma: a distinct clinicopathologic entity

A 51-year-old man presented with a paratracheal tumor. He had undergone resection of a thyroid tumor 15 years previously; at that time, the histologic diagnosis had been anaplastic carcinoma. When the tumor recurred, the presumptive clinical diagnosis was medullary thyroid carcinoma. Histologic examination revealed a poorly differentiated epithelial tumor with immunoreactivity for keratins, carcinoembryonic antigen, and, focally, S-100 protein. The tumor was negative for calcitonin and thyroglobulin. There were scattered lymphocytes and plasma cells. Ultrastructural examination showed elongated epithelial cells with prominent desmosomes and bundles of cytoplasmic tonofilaments but no secretory granules; amyloid was not present ultrastructurally or histochemically. The characteristic ultrastructural and immunocytochemical features and the clinical behavior of this tumor verify the existence of primary thyroid thymoma. This new primary thyroid neoplasm is of clinical importance, considering the more benign behavior of primary thyroid thymoma than of other tumors in the differential diagnosis of this lesion.

Anaplastic thyroid carcinoma. A clinical, histologic, and immunohistochemical study

Twenty-six cases of anaplastic thyroid tumor were investigated and reclassified using immunoperoxidase techniques. Sections of the neoplasms were stained immunohistologically for the following thyroid associated antigens: (1) thyroglobulin, which shows a positive reaction with follicular cells of the thyroid; (2) calcitonin, which is positive in medullary carcinoma of the thyroid; and (3) leucocyte common antigen (LC), which identifies lymphomata and Factor VIII-related antigen for hemangioendothelioma. Using these methods, five cases were reclassified. Three cases were identified as lymphomata, one case was reclassified as medullary carcinoma of the thyroid, and one case was identified as hemangioendothelioma. Eleven cases were confirmed to be anaplastic carcinoma of the thyroid and ten cases were negative for all the antigens tested. There was a significant difference in the survival of the groups of patients mentioned above. Prognostic data support the suggestion that immunohistochemical methods should be used for the precise classification of anaplastic carcinoma. In this way, tumors such as malignant lymphoma and medullary carcinoma, which resemble anaplastic carcinoma histologically but have a better prognosis, can be identified. This is important for planning surgical procedures and choosing chemotherapy and/or radiotherapy.

Small cell carcinoma of the thyroid. A reclassification of cases originally diagnosed as small cell carcinomas of the thyroid

99 cases of undifferentiated carcinomas of the thyroid and nine cases of primary malignant Non-Hodgkin lymphomas of the thyroid were examined from 1967 to 1983 in our institute. Among the undifferentiated carcinomas nine cases were classified as small cell subtype. Over the years, the histopathological handling in regard to small cell subtype of undifferentiated carcinoma and primary malignant Non-Hodgkin lymphoma has changed. The frequency of primary malignant Non-Hodgkin lymphoma has increased conspicuously in the last few years, whereas the number of small cell carcinomas decreased. A reclassification, based on immunohistochemical investigation for tumor markers of the nine cases originally diagnosed as small cell carcinomas from 1967 to 1983 revealed that five cases were poorly differentiated carcinomas or undifferentiated carcinomas of the spindle cell type. In three cases the primary diagnosis had to be revised into malignant Non-Hodgkin lymphoma of the diffuse "histiocytic" type. The postmortem examination of the patient with the remaining small cell carcinoma "of the thyroid" revealed a clinically undetected small cell carcinoma of the lung with metastases to the cervical lymph nodes and the thyroid gland. These findings are in agreement with the results of several recently published papers indicating that true small cell carcinoma of the thyroid must be a very rare tumor.