Signet Ring Cells in a Poorly Differentiated Hurthle Cell Carcinoma of the Thyroid Combined With Two Papillary Microcarcinomas

Thyroid collision tumor containing oncocytic carcinoma, classical and hobnail variants of papillary carcinoma and areas of poorly differentiated carcinoma

Collision tumors are rare and may comprise components with different behavior, treatments, and prognosis. We report an unprecedented case of aggressive thyroid collision tumor containing widely invasive oncocytic carcinoma (OC), classical and hobnail (HPTC) variants of papillary carcinoma, and poorly differentiated carcinoma (PDTC). The patient underwent total thyroidectomy, radioactive iodine therapy, and within months progressed with local recurrence, and pulmonary metastases requiring neck dissection, external radiotherapy and systemic treatment with sorafenib. The rapid progression, dedifferentiated metastatic lesions, and failure to treatments resulted in the patient's death. The great variety of histological types and the evolution of this case were a challenge for the management of metastatic disease. Widely invasive OC, HPTC and PDTC are considered to have a worse prognosis. HPTC has never been reported as a component of a collision tumor. HPTC and PDTC should call attention to a possible higher-grade transformation.

Congenital goiter with areas of signet ring cell differentiation in a juvenile giraffe: a very rare entity

BACKGROUND

Congenital goiter is a common thyroid metabolic disorder characterized by low levels of thyroid hormone, subsequent secretion of excess thyroid-stimulating hormone (TSH) from the pituitary gland, and compensatory hyperplasia of the glands. The presence of signet ring cells (SRCs) does not provide sufficient evidence for the diagnosis of a thyroid tumor, making histopathological diagnosis challenging. In addition, SRCs can also appear in congenital goiter. Therefore, a comprehensive diagnosis of congenital goiter is warranted based on clinical symptoms, autopsy, histopathology, and laboratory examination.

CASE PRESENTATION

A juvenile giraffe at the Ordos Zoo in Ordos presented with symptoms of loss of appetite, serious salivation, and slow growth rate since birth. Its height and weight were significantly lower than those of other giraffes of the same age. The animal ultimately died at 17 months of age. Autopsy revelaed that the thyroids were hard, with an uneven surface and with the presence of many small raised follicles, and dense in cross-section. Other organs were visibly atrophic. Histopathologically, diffuse follicles were irregular in size and shape in the hyperplastic goiter. Some follicles were collapsed due to lack of colloids. The follicles were lined by single or multiple layers of hyperplastic follicular cells (HFCs), some of which were exfoliated in the lumen. The HFCs were either cuboidal with eosinophilic cytoplasm and many red small granules or showed SRC differentiation, with nuclei pressed to one edge of the cell and distorted by cytoplasmic mucin that appeared as a single clear vacuole HFCs and as a foamy, multivesicular cytoplasmic material in others. Scattered necrosis of myocardial cells and hepatocytes, cerebral hemorrhage, necrosis of intestinal villi, and obvious atrophy of organs were also observed. Immunohistochemical tests were strongly positive for thyroglobulin and thyroid transcription factor-1 (TTF-1) in the cytoplasm of HFCs.

CONCLUSIONS

Here we present a case of congenital goiter with areas of SRC differentiation in the thyroid of a juvenile giraffe.

Primary Benign and Malignant Thyroid Neoplasms With Signet Ring Cells: Cytologic, Histologic, and Molecular Features

OBJECTIVES

Signet ring cells (SRCs) can be seen in a variety of thyroid tumors and can pose a diagnostic pitfall on cytology. This study describes the cytologic, histomorphologic, and molecular aspects of a cohort of primary thyroid tumors with SRCs.

METHODS

A search was performed of the Massachusetts General Hospital and Brigham and Women's Hospital (Boston, MA) pathology archives for the keywords thyroid, signet, and signet ring features between 2000 and 2014. Seven thyroidectomy specimens with corresponding thyroid fine-needle aspiration (FNA) were obtained. Cytology and histopathology slides were evaluated. Molecular analysis was performed using anchored multiplex polymerase chain reaction (AMP).

RESULTS

The cohort consisted of four follicular adenomas (FAs), two noninvasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTPs), and one secretory carcinoma (SC). The FNA diagnoses were atypia of undetermined significance (n = 3), suspicious for follicular neoplasm (n = 3), and suspicious for malignancy (n = 1). Molecular analyses revealed PTEN and FGFR3 mutations in an FA and NIFTP, respectively, and an ETV6-NTRK3 fusion in a case of primary thyroid gland SC.

CONCLUSIONS

Our study demonstrates the range of thyroid tumors with SRCs. While most thyroid tumors with SRCs are benign, primary thyroid SC should also be considered in the differential diagnosis.

Collision tumors of the thyroid: A case report and review of the literature

BACKGROUND

Collision tumors of the thyroid are a rare pathology that present a diagnostic and treatment challenge. In this report, we present an interesting case and a review of the current literature as to inform management.

METHODS AND RESULTS

An 88-year-old woman presented with acute airway compromise and vocal cord paralysis. CT identified a thyroid mass and widespread metastasis. Histopathology identified the lesion as a collision tumor consisting of a squamous cell carcinoma (SCC) and papillary thyroid carcinoma. The patient was managed with surgery and palliative radiotherapy. However, she died from complications of a lower respiratory tract infection. We also present a review of the literature with 33 cases reviewed.

CONCLUSION

Management of collision tumors is complex because of the duality of the pathology. They should be managed in a multidisciplinary team setting and treatment should be patient specific. Generally, the most aggressive neoplasm should guide treatment. We recommend surgical management with adjunct therapy.

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.

Axillary node metastasis from differentiated thyroid carcinoma with Hürthle and signet ring cell differentiation. A case of disseminated thyroid cancer with peculiar histologic findings

BACKGROUND

Differentiated thyroid cancer is usually associated with an excellent prognosis and indolent course. Distant metastases are rare events at the onset of thyroid cancer. Among these presentations, metastasis to the axillary lymph nodes is even more unusual: only few cases were previously reported in the literature; there has been no report of axillary lymph node metastasis from follicular thyroid carcinoma. Axillary lymph node metastasis generally arises in the context of disseminated disease and carries an ominous prognosis.

CASE PRESENTATION

Here we present a case of axillary lymph node metastasis in the context of disseminated differentiated thyroid cancer. The patient underwent near total thyroidectomy and neck and axillary lymph node dissection. A histopathological diagnosis of poorly differentiated follicular carcinoma with "signet ring cells" and Hürthle cell features was established. The patient received radioactive iodine therapy and TSH suppression therapy. Subsequently his serum thyroglobulin level decreased to 44.000 ng/ml from over 100.000 ng/ml.

DISCUSSION AND CONCLUSION

Currently there are only few reported cases of axillary node metastases from thyroid cancer, and to our knowledge, this is the first report on axillary lymph node metastasis from follicular thyroid carcinoma. "Signet ring cell" is a morphologic feature shared by both benign and, more rarely, malignant follicular thyroid neoplasm, and it generally correlates with an arrest in folliculogenesis. Our case is one of the rare "signet ring cells" carcinomas so far described.