Fine-needle aspiration biopsy of ectopic cervical spindle-cell thymoma: A case report

Abstract

In this report, we describe a case of ectopic cervical thymoma (medullary or type A thymoma, according to the WHO classification) located in the anterior cervical region (thyroid topography) that was submitted to ultrasound-guided fine-needle aspiration biopsy. The cytologic smears were moderately cellular to very cellular and were composed of numerous spindle-shaped cells placed predominantly in tissue fragments, with no specific arrangement. Isolated spindle-shaped cells were also present in a hemorrhagic background. The nuclei were elongated with finely granular chromatin and inconspicuous nucleoli. Mitosis, nuclear atypia, and necrosis were not detected. There was a scarce lymphoid population of small lymphocytes. The cytologic aspects, the correlation with histologic findings, and the differential cytologic diagnosis are reviewed.

Ectopic Cervical Thymoma: A Report of Two Cases of a Rare Entity Frequently Misdiagnosed on Fine Needle Aspiration Cytology and Frozen Section

“…This paper was published prior to the 1999 WHO Classification of thymic epithelial tumors. Since then, fewer than twenty cases of ECT have been published [2,[4][5][6][7][8][9][19][20][21][22][23][24][25]. Table 1 provides a list of the various reported subtypes as defined by the 1999/2004 WHO classification system where known.…”

“…ET has been reported in a variety of sites such as the neck (ectopic cervical thymoma, ECT) [2][3][4][5][6][7][8][9], chest wall [10], pleura [11], lung [12] and heart [13]. Among these ectopic sites, the cervical region appears to be one of the most frequent locations, where close proximity to the thyroid frequently results in a mistaken clinical impression of a primary thyroid neoplasm.…”

Aspiration cytology of an ectopic cervical thymoma misinterpreted as a lymphoproliferative lesion of the thyroid: A case report

“…Taweevisit et al (4) compiled the details of all 14 cases in a literature review. The initial cytological diagnoses included Hashimoto thyroiditis, lymphocytic thyroiditis, papillary and medullary carcinomas, malignant lymphoma of the thyroid and various types of soft-tissue tumor (3)(4)(5)7,(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). According to the 2004 WHO classification system, the thymoma subtypes were predominantly type AB and type B1, as well as two type A thymomas, one type B2 thymoma and one type B3 thymoma (5,6).…”

“…These tumors were misdiagnosed as primary thyroid carcinoma, metastatic carcinoma and various types of soft-tissue tumor (5,11,13,14,16). In one case, cohesive epithelial cell clusters with rare intranuclear inclusions were observed, resulting in the misdiagnosis as a (16).…”

“…Identifying typical cytological features, such as papillary architecture and nuclear changes, including powdery chromatin, nuclear grooves and the psammoma bodies observed in papillary thyroid carcinoma, which are absent from ectopic thymoma, may be useful for forming a differential diagnosis. For example, intranuclear inclusions and stromal amyloid do not occur in ectopic thymoma, and, thus, may be useful for distinguishing it from a spindle-cell lesion, such as a medullary carcinoma (13).…”