Fine-needle aspiration cytology of columnar-cell carcinoma of the thyroid: report of two cases with cytohistologic correlation

FNA cytology of columnar cell variant of papillary thyroid carcinoma: A case report with review of literature

Cytological features such as papillary configuration, pseudostratification, and large rosette‐like clusters without any nuclear features of PTC hint at the CCVPTC diagnosis.

The presence of papillary configuration, pseudostratification, and large rosette‐like clusters without any nuclear features of PTC hint at CCVPTC.

Cytologic features of aggressive variants of follicular-derived thyroid carcinoma

Certain carcinomas of the thyroid gland behave aggressively resulting in increased patient morbidity and poor patient prognosis. The diagnosis of these aggressive thyroid cancer subtypes is sometimes challenging and subject to increased interobserver variability. This review deals with the cytological features of such tumors including aggressive variants of papillary thyroid carcinoma, poorly differentiated thyroid carcinoma, and anaplastic thyroid carcinoma. These malignancies fall into 2 groups based on their cytomorphology: those that exhibit distinct microscopic features (eg, nuclear findings typical of classical papillary thyroid carcinoma or marked anaplasia) and those that present with more subtle cytologic features (eg, nuclear pseudostratification, "soap bubble" nuclei, supranuclear or subnuclear cytoplasmic vacuoles, rosette-like structures, hobnail cells). We review the literature regarding these aggressive thyroid cancers and highlight important phenotypic characteristics that can be useful for their diagnosis based on fine needle aspiration.

Update on the cytologic features of papillary thyroid carcinoma variants

Papillary thyroid cancer (PTC), which accounts for 85-90% of all thyroid cancers, is generally an indolent tumor with long term survival rates >95%. A reliable definitive diagnosis of PTC is usually straightforward in fine needle aspirates of conventional PTC whenever the characteristic papillary and/or flat honeycomb sheet-like architecture and the typical nuclear features of chromatin pallor, nuclear enlargement, crowding, grooves and pseudoinclusions are encountered. Conventional PTC, however, has diminished in relative frequency as compared to PTC variants, especially the noninvasive follicular variant of PTC, an indolent tumor which has recently been reclassified as "noninvasive follicular thyroid neoplasm with papillary-like nuclear features" (NIFTP). These PTC variants are characterized by various architecture, cell type and shape, and stromal features, some of which can be recognized cytologically. Awareness of the cytomorphological spectrum and of the characteristic cytological features of these PTC variants is important to avoid diagnostic pitfalls. In this article, we review the different variants of PTC, including their cytomorphologic features, differential diagnosis, and salient molecular features. Diagn. Cytopathol. 2017;45:714-730. © 2017 Wiley Periodicals, Inc.

Cytomorphology of columnar cell variant of papillary carcinoma thyroid: A case report and review of the literature

A 58 years old lady reported with history of progressively increasing lump in the neck. Patient had earlier undergone sub-total thyroidectomy (details not available) in a private institute one year back. Fine needle aspiration cytology (FNAC) of the present lump revealed features of papillary carcinoma thyroid. Patient subsequently underwent total thyroidectomy along with excision of a tumor nodule in the larynx. Gross examination of the specimen revealed a tumor nodule in the right lobe of the thyroid. Microscopic examination of the tumor nodule in the thyroid and larynx revealed a columnar cell variant of papillary carcinoma thyroid. Very few reports describing the cytomorphologic features of this variant of papillary carcinoma are available in the published literature. These reports highlight the absence or paucity of nuclear grooves and intranuclear inclusions in this variant. We describe a case of columnar cell variant of papillary carcinoma where nuclear grooves were prominently seen. In addition, we report the occurrence of rosette-like structures which were brought out better on FNA smears. These rosette-like structures have not been emphasized earlier in the published literature. The cytomorphologic features of this rare variant are also reviewed in this report.

Aggressive variants of follicular cell-derived thyroid carcinomas: a cytopathologist's perspective

Follicular cell-derived carcinomas of the thyroid gland comprise a heterogeneous group of malignant neoplasms of the thyroid gland with varied histologic appearance and molecular profiles. In most patients, these tumors represent relatively indolent neoplasms; however, certain subtypes/variants behave in an aggressive manner, and the recognition of this subset of tumors is essential because of their variable response to therapy and significant morbidity and mortality. Fine-needle aspiration is considered an essential tool for the diagnosis of suspicious thyroid nodules. In this review, the authors discuss the clinical, histologic, and molecular findings and the prognostic implications of aggressive thyroid neoplasms with emphasis on the characteristic cytomorphologic features on fine-needle aspiration smears.

Clinicopathological and molecular characterization of nine cases of columnar cell variant of papillary thyroid carcinoma

The majority of papillary thyroid carcinoma is indolent and associated with long-term survival. The columnar cell variant, however, is a rare subtype that is variable in biological behavior; some are clinically aggressive, whereas others are more clinically indolent. Tumor size, tumor circumscription, and encapsulation may influence the behavior of columnar cell carcinomas. Other variables including genetic changes and putative biomarkers associated with malignant growth have not been thoroughly examined in these neoplasms. In this study, nine cases of columnar cell variant of papillary thyroid carcinoma from three institutions were classified as clinically indolent or aggressive based on pathological features, clinical history, and outcome. Indolent tumors were typically small, circumscribed or encapsulated, and from younger female patients, whereas aggressive tumors were large, locally aggressive, associated with regional and distant metastasis, and from older male patients. The missense mutation, V600E in the BRAF oncogene (BRAF(V600E)), was detected in three of nine of cases, of which two were clinically aggressive. Immunohistochemical evaluation of neoplasia-associated markers showed increased nuclear cyclin D1 expression, elevated Ki-67 proliferation indices, and predominantly weak nuclear p53 staining in both indolent and aggressive tumors. Expression of β-catenin was largely restricted to a membranous pattern in both tumor types. Cytoplasmic expression of bcl-2 was overall mildly reduced in indolent neoplasms. Nuclear expression of estrogen and progesterone receptors was increased in both indolent and aggressive neoplasms, but was without sex- or age-related differences; however, whereas progesterone receptor expression was diffuse and strong in clinically indolent carcinomas, its expression was diminished in aggressive neoplasms. Recognition of the clinicopathological characteristics and the molecular and immunophenotypic features of the columnar cell variant of papillary thyroid carcinoma may aid in characterizing neoplasms that behave indolently or aggressively.

Encapsulated Columnar-cell Carcinoma of the Thyroid: A Case Report

Columnar-cell carcinoma is a rare form of papillary thyroid carcinoma. It is a biologically aggressive variant, according to the World Health Organization classification, due to its rapid growth, high local recurrence rate, and frequent lung, brain, and bone metastases. However, recent reports indicate encapsulated tumors confined to the thyroid gland are associated with a more favorable prognosis. We report a case of encapsulated columnar-cell carcinoma occurring in the right lobe of the thyroid in a 25-year-old female and discuss the histopathologic features, differential diagnosis, and prognostic factors.

Solitary parotid metastasis from columnar cell carcinoma of the thyroid: a diagnostic dilemma

A 65-yr-old woman presented in May 1998 with a left parotid mass of 2 yr duration. The cytology and histopathology of the parotid lesion showed features of a columnar cell carcinoma. In November, 1967, she was diagnosed to have a classic papillary thyroid carcinoma (PTC). Ultrasound examination revealed a persistent thyroid nodule, the aspiration cytology of which confirmed columnar cell variant of papillary thyroid carcinoma (CCV-PTC). CCV-PTC is a recently described rare tumor of the thyroid that has been associated with an aggressive clinical course. Our case was peculiar in that the patient presented with an isolated metastasis in the parotid gland. Second, after an indolent course following the initial diagnosis of usual PTC 31 yr ago, she had now developed a more aggressive variant of the tumor.