Sebaceous lymphadenoma of the thymus: A clinicopathologic and immunohistochemical study of 2 cases

Sebaceous Lymphadenoma: Radiology-Pathology Correlation

Sebaceous lymphadenoma is a rare salivary gland neoplasm most commonly occurring in the sixth to eighth decades of life. Cross sectional imaging typically demonstrates a multicystic expansile mass, most commonly occurring in the parotid gland, where the radiographic differential diagnosis would include Warthin tumor in this location and age group. Ultimately, the diagnosis is confirmed with the histopathologic findings of tubuloglandular epithelial profiles with sebaceous differentiation and cystic change set within a dense, benign lymphocytic infiltrate. These features are exemplified in this sine qua non radiology-pathology correlation article.

Benign lesions of the mediastinum: A review with emphasis on cytology and small biopsy specimens

This review focuses on the diagnosis of select benign processes, ranging from reactive entities to heterotopic tissues to neoplasms, which may occur in the mediastinum. Currently, the mediastinum can be evaluated and biopsied with endoscopic procedures. Therefore, cytopathology specimens, fine needle aspirations, and small biopsies play an important role in the diagnosis of these lesions. In this review, an emphasis is given to relevant clinical presentations, histologic and cytologic findings, differential diagnoses, ancillary testing, and interpretation. Pitfalls are reviewed and discussed in each section. It is important for both surgical pathologists and cytopathologists to be familiar with these entities and their cytologic and histologic features that may be helpful in reaching a diagnosis.

Non-Neoplastic and Benign Tumoral Lesions of the Thymic Gland: A Review and Update

The thymus is a dynamic organ that undergoes changes throughout life and can demonstrate a myriad of pathologic alterations. A number of benign entities of the thymus prove to be diagnostic dilemmas owing to their resemblance and association with true thymic tumors. These are usually discovered incidentally on routine imaging and most patients are either asymptomatic or present with signs and symptoms of compression of adjacent organs. The radiologic appearance of these lesions varies from simple cysts to complex masses that are suspicious for malignancy. The diagnosis is usually made purely on morphologic grounds, however, immunohistochemical stains can help rule out possible differential diagnoses. Surgical removal is usually curative in these lesions and recurrences are rare. The prognosis is excellent, however, some of these lesions may be associated with myasthenia gravis and/or thymomas. In this review, we describe non-neoplastic lesions and benign tumoral lesions of the thymus, with emphasis on the clinical, radiologic, and pathologic features. The differential diagnosis of each entity is also discussed.

Xanthomatous Thymoma: A Clinicopathologic and Immunohistochemical Study of 10 Cases

OBJECTIVES

Ten cases of thymomas with an extensive xanthomatous component are presented.

METHODS

Cases were identified during a review of more than 500 cases of thymomas. Histologic material from surgical resections was evaluated.

RESULTS

The patients included five men and five women aged 47 to 64 years who had nonspecific symptoms. Grossly, all tumors were solid, measuring 2.5 to 4.5 cm. Eight tumors were encapsulated; two were minimally invasive. Histologically, the tumors showed varying histologies, all with an extensive xanthomatous component comprising 50% to 80% of the tumor. Immunohistochemical stains showed tumor cells positive for keratin and keratin 5/6 while the xanthomatous component was positive for CD68. Follow-up information showed nine patients remain alive with no recurrence. No follow-up information was obtained in one patient.

CONCLUSIONS

The presence of an extensive xanthomatous component may pose difficulties in the interpretation of these tumors. This study highlights the importance of proper sampling and awareness of this unusual feature.

Primary Salivary Gland Type Tumors of the Thymus

The existence of primary salivary gland type tumors (SGTs), similar to those occurring in the major salivary glands, is well known in the thoracic cavity. When they occur in this anatomic area, these tumors more commonly arise from the lung. However, the existence of these tumors primarily affecting the thymus, although recognized in the literature, is rather not well documented or known. In addition, contrary to the primary lung SGTs, which are predominantly of the malignant type, these tumors when occur in thymus encompass a wider spectrum of biology ranging from benign to low grade, and high grade malignancy. The recognition of SGTs in the thymus, even though rare, is important to properly address treatment and prognosis. Herein, we will discuss the numerous benign a malignant SGTs that have been described in the thymus and highlight the difficulty that these tumors may pose when occurring in the thymic area.