CDX2 expression in columnar variant of papillary thyroid carcinoma

Wnt3a but not CDX-2 expression is associated with differentiated thyroid cancer

OBJECTIVE

Thyroid neoplasm incidence has increased worldwide, mostly due to the advancements in medical imaging and screening rates. The aberrant Wnt/β-catenin pathway has been identified as a key mechanism, and it has also been related to the metastatic activity of differentiated thyroid cancer. We aimed to verify the difference in the expression of Wnt3a, a canonical activator of the β-catenin signaling, and CDX-2, a transcription factor upregulated by Wnt/β-catenin pathway, in multinodular goiter and differentiated thyroid cancer and to determine their prognostic value.

METHODS

We included 194 thyroid tissue surgical specimen and their clinicopathological data: study group (differentiated thyroid cancer, n=154) and control group (multinodular goiter, n=40). Immunohistochemistry (IHC) was performed on formalin-fixed, paraffin-embedded tissue by the primary antibodies Wnt3a and CDX-2.

RESULTS

High Wnt3a expression was significantly associated with differentiated thyroid cancer (p=0.031). CDX-2 was negative in all differentiated thyroid cancer cases (100%) and also in multinodular goiter. Wnt3a expression was significantly associated with tumors ≤20 mm (p=0.044) and with the absence of capsule invasion (p=0.031). The multivariate analyses suggested that older age (≥55), independent of capsular invasion and tumor size, was an independent prognostic factor for Wnt3a expression (p=0.058).

CONCLUSIONS

Wnt3a expression but not CDX-2 is correlated with differentiated thyroid cancer samples in comparison to multinodular goiter. Although its prognostic value was limited to tumor size and capsule invasion, a combined model in a panel of immune markers can add accuracy in the classification of challenging thyroid follicular-derived lesions.

Adenocarcinoma NOS arising from accessory lacrimal glands: A case report and a review of the literature

Primary malignant epithelial tumours arising from accessory lacrimal glands (ALGs) are extremely rare, with only few cases reported in literature. They generally appear as gradually increasing masses of the upper or the lower eyelid. Only one case of primary adenocarcinoma or adenocarcinoma not otherwise specified (ACNOS) from ALGs has been reported in literature. Herein, we describe a case of ACNOS arising from ALGs with an atypical clinical presentation and review prior cases of ALGs epithelial malignancies reported in the literature. A 78-year-old man referred to our Ocular Oncology Unit for adjuvant therapy after the excision of a conjunctival tumour of the left eye with a histological diagnosis of squamous cell carcinoma. He underwent topical chemotherapy with MMC and during follow up he presented a multinodular iris mass in his left eye. The MRI of the orbit showed an ocular mass infiltrating orbital soft tissues of the inferior palpebral region with an involvement of the corresponding zygomatic cutis. We performed orbital exenteration and histological studies revealed an epithelial neoplasm with a solido-glandular growth pattern with lumens containing an eosinophilic material positive for PAS and PAS-D. The immunohistochemical findings confirmed the diagnosis of adenocarcinoma NOS from ALGs. Although ALGs epithelial malignancies are extremely uncommon, they should be considered in the differential diagnosis of ocular tumours. A vigilant approach towards these entities is required, since they can be clinically insidious and locally aggressive.

[Histopatological and molecular genetic characteristics of clinically aggressive variants of papillary thyroid carcinoma]

Papillary carcinoma is the most commonly diagnosed form of well-differentiated thyroid cancer that is generally characterized by a favorable prognosis. However, a number of relatively rare variants of this tumor, such as papillary carcinoma of high cells, papillary carcinoma of columnar cells, a diffuse sclerosing variant and recently described cancer of shoe nail cell type, are characterized by a less favorable clinical course, a high frequency of distant metastasis, and relatively low overall and relapse-free survival rates. In this connection, it is important to recognize these options at the stage of a primary morphological study. This review of the literature considers the morphological, clinical and molecular genetic features of the above variants of papillary thyroid carcinoma.

Among sinonasal tumors, CDX-2 immunoexpression is not restricted to intestinal-type adenocarcinomas

Intestinal-type adenocarcinoma (ITAC) is a rare form of sinonasal cancer characterized by an association with exposure to industrial dusts, aggressive clinical behavior, and histologic/immunophenotypic similarity to tumors of the gastrointestinal tract. ITAC is sometimes very poorly differentiated and difficult to distinguish from other sinonasal neoplasms, particularly in a limited biopsy. CDX-2 and cytokeratin 20 are consistently immunoreactive in ITAC and as a result, these immunostains are often used to support the diagnosis. However, CDX-2 and cytokeratin 20 have not been tested on a broad range of sinonasal tumors, so their specificities remain unknown. Immunohistochemistry for CDX-2 and cytokeratin 20 was performed on 6 sinonasal ITACs as well as 176 non-intestinal-type sinonasal neoplasms. CDX-2 and cytokeratin 20 were positive in all 6 cases of ITAC. CDX-2 immunoexpression was also observed in 17 of 176 (10 %) non-intestinal-type tumors including 6 of 16 (38 %) sinonasal undifferentiated carcinomas, 8 of 81 (10 %) squamous cell carcinomas (including 5 of 39 non-keratinizing variants), 2 of 20 (10 %) salivary-type adenocarcinomas, and 1 of 2 (50 %) small cell carcinomas. In contrast, among non-intestinal types of sinonasal tumors, cytokeratin 20 was only focally observed in 1 of 176 non-intestinal tumors (a non-keratinizing squamous cell carcinoma). All cases of non-intestinal surface-derived adenocarcinoma and esthesioneuroblastoma were negative for both markers. Both CDX-2 and cytokeratin 20 are highly sensitive for the diagnosis of sinonasal ITAC, but cytokeratin 20 is more specific. CDX-2 staining may be observed in other high grade tumor types, especially sinonasal undifferentiated carcinoma and non-keratinizing squamous cell carcinoma. As a result, in the setting of a poorly differentiated sinonasal carcinoma the diagnosis of ITAC should not be based on CDX-2 immunoexpression alone. Clear-cut glandular differentiation and cytokeratin 20 immunoexpression are more reliable features.