Signet ring carcinoma of the female breast: a clinicopathologic analysis of 24 cases.

Signet ring carcinomas of the breast have been separated recently as an aggressive subtype of breast cancer, distinct from mucinous (colloid) carcinomas. Twenty-four cases of signet ring breast cancer (2% of total breast cancers at the authors' institution) were analyzed. The authors' study indicates that histogenetically such lesions are derived from lobular, not ductal, cells since mucin patterns and ultrastructural features are shared.

Malignant carotid body tumors: report of two cases and review of the literature.

Paragangliomas may arise in any area of the body where nonchromaffin paraganglia are situated. These include the glomus jugulare, the carotid body, and the retroperitoneum. Malignant behavior of these paragangliomas has been a controversial subject with most authors, who consider them to be benign tumors.

Elastofibroma dorsi: an immunochemical study of collagen content.

The types of collagen present in a case of elastofibroma dorsi were determined using type specific, characterized collagen antibodies. The presence of type II collagen (normally present only in articular cartilage and in selected ocular structures) is discussed with regard to the pathogenesis of this lesion, and the use of collagen antibodies is discussed with regard to their potential value in better characterizing and classifying mesenchymal tumors.

Pseudolymphoma of the breast.

A case of pseudolymphoma of the breast presenting as an isolated tumor mass in the breast of a 56-year-old female is described. Recognition of this rare lesion is important in order to differentiate it from other malignant neoplasms.

Inflammatory malignant fibrous histiocytoma.

This report describes a 13-year-old girl with inflammatory malignant fibrous histiocytoma of the abdomen. Clinical, pathologic, and ultrastructural features of this subgroup of tumors are discussed. Differential diagnostic criteria are reviewed.

Fibrothecoma of the broad ligament.

We present a patient with a primary extraovarian fibrothecoma, an extremely rare lesion originating in the broad ligament. Possible sources of origin and significance are discussed.

Squamous cells in the human thyroid gland.

Squamous epithelium in the thyroid, which may be basaloid, epidermoid, or truly squamous, may be derived from several sources. In the normal thyroid, usually rests of one type or another are responsible for these cell nests. Thus, thymic or ultimobranchial remanants may be found in the lateral lobes of normal thyroid glands.

Pleomorphic adenomas of the parotid gland resembling mesenchymal tumors.

Two cases of unusual pleomorphic adenoma of the parotid gland are described. Each showed marked palisaded zones. Distinction from smooth muscle tumors, neurofibromas, and other spindle-cell neoplasms is described.