Mucinous carcinoma of thyroid gland. Report of a primary and a metastatic mucinous tumour from ovarian adenocarcinoma with immunohistochemical study and review of literature

Prevalencia de tumores metastásicos en la glándula tiroides. Revisión sistemática y metanálisis

Introducción y objetivo: Los tumores metastásicos en la glándula tiroides complican el diagnóstico, el tratamiento y el pronóstico del paciente. El objetivo es conocer la prevalencia de las metástasis en la glándula tiroides referida en la literatura médica y los tumores primarios que con más frecuencia metastatizan en la glándula tiroides. Método: Se realizó una revisión bibliográfica sistemática en las bases de datos de PubMed, La Biblioteca Cochrane y Scopus. Los artículos seleccionados se dividieron en dos grupos, series clínicas de pacientes en los que se hallaron metástasis en tiroides (grupo A) y series de hallazgos de metástasis en tiroides en autopsias (grupo B). Se realizó metanálisis de prevalencia para cada grupo de artículos siguiendo el modelo de efectos aleatorios. Resultados: La prevalencia en cada grupo con su índice de confianza al 95% fue 0.00479 (0.002-0.007) para el grupo A y 0.0362 (0.014-0.059) para el grupo B. La prevalencia de metástasis halladas en autopsias fue 7,58 veces mayor que en los estudios clínicos. En el grupo A la edad media fue 60.82 y en el grupo B 57.20. En ambos grupos las metástasis halladas en tiroides fueron más frecuentes en el sexo femenino. La localización del tumor primario fue diferente en ambos grupos, en el grupo A fue el cáncer de riñón y en el grupo B el cáncer de mama. La variabilidad de la prevalencia de metástasis en tiroides en los diferentes artículos de ambos grupos hace que este estudio tuviese una alta heterogeneidad (índice I2 y Q). Los funnel plot de ambos grupos indicaron alto sesgo de publicación. Discusión: La diferente prevalencia entre series clínicas y autopsias puede implicar que la detección de metástasis en tiroides en la clínica está infradiagnosticada. La razón de esto podría ser que las metástasis intratiroideas se presentan de forma asintomática siendo diagnosticadas como hallazgo casual en autopsias. En otras ocasiones se presentan como un nódulo tiroideo años después del tumor primario, lo que condiciona el diagnóstico. Conclusiones: La prevalencia de metástasis en tiroides es superior en las series de autopsias que en series clínicas (hasta 6.67 veces más frecuente en nuestro estudio). Las metástasis intratiroideas probablemente están infradiagnosticadas por cursar sin clínica siendo diagnosticadas como hallazgo casual en autopsias. Los tumores primarios más frecuentes fueron el riñón (series clínicas) y la mama (series de autopsias).

Primary mucinous carcinoma of thyroid gland with prominent signet-ring-cell differentiation: a case report and review of the literature

Purpose

This study reports a case of primary mucinous carcinoma of the thyroid gland with signet-ring-cell differentiation, and reviews the literature to evaluate its real incidence and the prognosis of these patients.

Patients and methods

A 74-year-old Chinese woman, presenting with a mass in the right lobe of thyroid gland, came to the hospital. Computed tomography revealed a mass in the right lobe of the thyroid gland, accompanied with right neck lymphadenectasis and airway deviation caused by tumor compression. Thyroid imaging suggested a thyroid malignant tumor and suspicious lymph node metastasis. Histologically, the tumor was characterized by the tumor cells arranged in small nests or trabeculae with an abundant extracellular mucoid matrix. The tumor cells formed diffuse invasion among thyroid follicles. In the peripheral regions, prominent signet-ring-cells formed a sheet-like structure and extended into the extrathyroidal fat tissue. The tumor cells were diffusely positive for thyroid transcription factor-1 (TTF-1) and PAX8, while they were focally positive for pan-cytokeratin (AE1/AE3) and weakly expressed thyroglobulin.

Results

Based on the histological features and immunohistochemical profile, a diagnosis of primary mucinous carcinoma of the thyroid gland with signet-ring-cell differentiation was rendered.

Conclusion

Using a panel of immunohistochemical markers may be helpful for differential diagnosis and for determining whether the tumor is primary or not.

Mucinous carcinoma of the thyroid: A case report and review of the literature

We report the case of a primary mucinous carcinoma of the thyroid in a man of 74 who had a 4-cm nodule in the right lobe of the thyroid, with a solido-cystic appearance on ultrasound associated with lymph node metastases. On scintigraphy, the nodule was hot and not extinctive. The patient underwent total thyroidectomy with a ipsilateral right lymph node dissection. The immunohistochemical study showed the negativity of CK 7 and CK 20 and the positivity of thyroglobulin and TTF 1. Postoperatively the rate of blood thyroglobulin 3 months after surgery had collapsed to 0.17ng/ml. The evolution was marked by the appearance of pulmonary metastasis and the patient died 4 months after surgery. Histological study showed the presence of almas of neoplastic cells surrounded by large deposits of extracellular mucin. Primitive mucinous carcinoma of the thyroid is a rare tumor which differential diagnosis is established on the positive immunohistochemistry of thyroglobulin and TTF1 but negative for other markers.

Primary mucinous carcinoma with rhabdoid cells of the thyroid gland: a case report

Background

Primary mucinous carcinoma of the thyroid gland is a rare disease; only 6 cases of primary mucinous carcinoma of the thyroid have been previously reported. Primary mucinous carcinoma of the thyroid gland with incomplete tumor resection tends to be associated with a poor prognosis, resulting in death within a few months. An early and appropriate diagnosis may contribute to improvement in patient prognosis; however, it is extremely difficult to diagnose primary mucinous carcinoma of the thyroid. We present the seventh reported case of primary mucinous carcinoma in the thyroid gland; moreover, rhabdoid cells were detected, which, to our knowledge, is a novel finding.

Case presentation

An 81-year-old Japanese woman was initially diagnosed with a poorly differentiated thyroid carcinoma, and she underwent a hemithyroidectomy. Pathological examination revealed the presence of abundant mucus and agglomeration of large atypical cells. Rhabdoid cells were also seen scattered among the tumor cells. Immunostaining was performed for various markers, and on the basis of these results, we diagnosed the lesion as primary mucinous carcinoma with rhabdoid cells in the thyroid gland. Ten months after surgery, recurrence was noted in the paratracheal lymph nodes; therefore, total resection of the residual thyroid gland and paratracheal lymphadenectomy with thyroid-stimulating hormone suppression were performed. The patient is currently alive and disease-free.

Conclusions

The current case is of interest not only because of the rare histological findings, but also because the patient achieved long-term survival following diagnosis of a mucinous carcinoma. We believe this report will be helpful for diagnosing future cases of mucinous carcinoma of the thyroid.

Mucinous Variant of Follicular Carcinoma of the Thyroid Gland: Case Report and Review of the Literature

The rare reports of mucinous variant of follicular carcinoma of the thyroid gland have not provided enough evidence to support the recognition of these tumors as a distinct clinicopathologic entity or to understand their etiopathogenesis. We report the fourth case of mucinous variant of follicular carcinoma displaying a minimally invasive tumor with diffuse expression of thyroglobulin, TTF-1, CD56, PAX-8, cytokeratins 7 and 19, in the absence of monoclonal carcinoembryonic antigen (CEA), cytokeratin 20, chromogranin, HBME-1, P63 expression, and BRAF gene mutation, in a 51-year-old woman who is alive without signs of disease 13 months after total thyroidectomy, bilateral neck dissection, and radioactive iodine. Herein, fine-needle aspiration cytology disclosed "worrisome" cytologic features consisting of large epithelial cells arranged in clusters or singularly, with high nucleocytoplasmic ratio, nuclear grooves and evident nucleoli which were shared by those of mucin-producing papillary thyroid carcinoma. Therefore, knowledge of the cytological and histopathological spectrum of this lesion is important to avoid misdiagnosis. The morphologic clues leading to the correct diagnosis of mucinous variant of follicular neoplasm have been correlated with the data of the literature, and the differential diagnosis is briefly discussed.

Follicular thyroid carcinoma with signet ring cell morphology: fine-needle aspiration cytology, histopathology, and immunohistochemistry

Thyroid follicular neoplasms with signet ring cell morphology represent a challenging cytological and histopathologic diagnosis. The low frequency of these neoplasms and their broad differential diagnosis contribute to this difficult scenario. Here, we present an exceptionally rare case of thyroid follicular carcinoma with signet ring cell morphology in a 62-year-old female. We analyze the characteristics in fine-needle aspiration cytology, histopathology, and immunohistochemistry and compare our results in a discussion with previous literature reports.

Follicular adenoma with extensive extracellular mucin deposition: report on two cases

We report two cases of follicular adenoma of the thyroid with extensive extracellular mucin deposition. Fine needle aspiration in Case 1 showed singly discohesive polygonal cells in a granular mucinous background. They contained abundant eosinophilic cytoplasm, nuclear irregularities, and frequent nuclear inclusions with occasional bizarre mitoses. A right lobectomy was done. In Case 2, a 47-year-old Caucasian woman with multinodular goiter had total thyroidectomy and a yellow-tan nodule was found within the right lobe. Both tumors were well-encapsulated masses with thick capsules. Each was characterized by microfollicles without papillae in a mucinous stroma. Tumor cells were positive for thyroglobulin and negative for calcitonin, CEA, galectin-3, HBME-1, and CK19. The extracellular mucin stained with Alcian-blue and colloidal iron but not with mucicarmine and D-PAS. No BRAF gene mutation was detected. Because there were neither capsular nor vascular invasions, both cases were diagnosed as follicular adenomas of the thyroid with extensive extracellular mucin deposition, which as proposed by the WHO classification can be categorized as a mucinous variant of follicular adenoma. Retrospectively, frequent nuclear inclusions and the absence of nuclear grooves in the mucin-containing background of cytologic smears and histologic sections were shared by those of mucin-producing papillary carcinoma. It is unclear whether it belongs to an existing category of thyroid neoplasm with mucin production or whether it is truly a new tumor variant. Furthermore, pathologists should pay attention to avoid misdiagnosis of this variant of follicular neoplasm that shows an overlapping cytology with that of papillary carcinoma.