Signet Ring Cell Adenoma Thyroid – A Case Report

Signet ring cell adenoma is a rare thyroid neoplasm which usually present as a solitary nodule. Histopathologically it can very well be mistaken for a metastatic signet ring cell lesion, as both of them shows cells with intracytoplasmic vacuole and eccentrically pushed nucleus. The intracytoplasmic vacuole in signet ring cell adenoma stain positive for thyroglobulin which help in confirming the diagnosis. Here we describe a case of signet ring cell adenoma of thyroid in a 46-year-old female with its cytological, histological and immunohistochemical features.

ONCOCYTIC INTRATHYROID PARATHYROID ADENOMA MASQUERADING AS HURTHLE CELL NEOPLASM: FINE NEEDLE ASPIRATION CYTOLOGY OF TWO CASES

Ectopic parathyroid adenomas in thyroid tissue are uncommon (0.7 - 6%), and their oncocytic variants are exceedingly rare. We report two cases of intrathyroid parathyroid adenoma which were diagnosed as Hurthle cell adenoma on cytology. Case 1 is a 49-year-old female with a 2.4 cm hypoechoic nodule in the left lateral neck. Electrochemiluminescent immunoassay of the aspirate revealed PTH level of 422 pg/ml, conrming the presence of hyperfunctional parathyroid tissue. Subsequent resection of the left thyroid lobe revealed an enlarged intrathyroidal parathyroid. Case 2 is a 58-year-old female with a 2.1 cm hypoechoic nodule in the posterior-mid left thyroid lobe. Strong overexpression of parathyroid hormone and Chromogranin A genes and low expression of thyrocyte-related genes suggested parathyroid origin of the cells sampled. MEN1 mutation and multiple copy number alterations indicated the neoplastic nature of the nodule. Parathyroid oxyphil cells and oncocytic thyrocytes share cytomorphological ndings and distinguishing them by cytology alone is challenging, especially when the targeted lesion is intrathyroidal. Distinguishing intrathyroid oncocytic parathyroid adenoma from oncocytic thyroid follicular lesions has signicant clinical implications as Bethesda-IV category lesions have 20%–30% risk of malignancy. While stippled chromatin or intracytoplasmic fat vacuoles may be suggestive of parathyroid origin, these are not specic. Classifying the origin of a nodule as parathyroid vs thyroid rests upon the detection of PTH in aspirate material by ECL, immunocytochemistry or next-generation sequencing. In parathyroid aspirates, PTH level 100 pg/mL is suggestive of the presence of PTH-secre ≥ ting tissue at the site biopsied or along the needle track.

Basal cell adenoma of the parotid gland: A rare entity

Basal cell adenoma (BCA) is a rare benign salivary gland tumor accounting for only 1–2% of all salivary gland tumors. We report a case of a 50-year-old man presenting a BCA of the parotid gland. A pleomorphic adenoma was initially suspected based on radiological features and fine needle aspiration cytology findings (FNAC).

Genetics, Diagnosis, and Management of Hürthle Cell Thyroid Neoplasms

Hürthle cell lesions have been a diagnostic conundrum in pathology since they were first recognized over a century ago. Controversy as to the name of the cell, the origin of the cell, and even which cells in particular may be designated as such still challenge pathologists and confound those treating patients with a diagnosis of “Hürthle cell” anything within the diagnosis, especially if that anything is a sizable mass lesion. The diagnosis of Hürthle cell adenoma (HCA) or Hürthle cell carcinoma (HCC) has typically relied on a judgement call by pathologists as to the presence or absence of capsular and/or vascular invasion of the adjacent thyroid parenchyma, easy to note in widely invasive disease and a somewhat subjective diagnosis for minimally invasive or borderline invasive disease. Diagnostic specificity, which has incorporated a sharp increase in molecular genetic studies of thyroid tumor subtypes and the integration of molecular testing into preoperative management protocols, continues to be challenged by Hürthle cell neoplasia. Here, we provide the improving yet still murky state of what is known about Hürthle cell tumor genetics, clinical management, and based upon what we are learning about the genetics of other thyroid tumors, how to manage expectations, by pathologists, clinicians, and patients, for more actionable, precise classifications of Hürthle cell tumors of the thyroid.