Paraganglioma‐like medullary thyroid carcinoma: A case report and literature review

Medullary thyroid carcinoma (MTC) accounts for 3%‐5% of all thyroid malignancies. Most MTC can be diagnosed by their typical cytologic and histologic morphology and immunohistochemical features. However, some rare variants of MTC may pose diagnostic difficulties on both cytology and histology. Paraganglioma‐like MTC (PLMTC) is a rare, but widely recognized variant of MTC. PLMTC is known to share morphological and architectural similarities with paraganglioma, hyalinizing trabecular tumor, and carcinomas of thyroid follicular cell origin, such as follicular carcinoma and follicular variant of papillary thyroid carcinoma. The combination of clinicopathologic features and a battery of immunohistochemical markers is essential for making a correct diagnosis. Herein, we report one case of PLMTC with both cytologic and histologic features and review the clinicopathologic features of previously reported cases.     

Sclerosing mucoepidermoid carcinoma with eosinophilia of thyroid gland in a male patient: a case report and literature review

Sclerosing mucoepidermoid carcinoma with eosinophilia (SMECE) was first described by Chan et al in 1991. It is characterized by nest or strands of epidermoid tumor cells with squamous differentiation, rare mucous cells, prominent sclerotic stroma, eosinophilic and lymphoplasmacytic infiltration, and a background of chronic lymphocytic thyroiditis in the non-neoplastic thyroid gland. It is important to recognize SMECE of thyroid and differentiate it from squamous cell carcinoma or other neoplasms with squamous differentiation/metaplasia. In published cases, the SMECE of thyroid gland predominantly occurs in women. We report a case of SMECE of thyroid in a 45-year-old male patient. All cases in male patients were Caucasian described in English literature, and our case is the first one in Asian.     

Plasmacytoma and follicular lymphoma in a case of Hashimoto''s thyroiditis

Monoclonal gammopathy (IgG, lambda) in a 37-year-old man with Hashimoto's thyroiditis, was markedly decreased after thyroidectomy. Histological examination of the thyroid showed large lymphoid follicles surrounded by a massive proliferation of plasma cells. Immunological studies revealed that interfollicular plasma cells stained monotypically for lambda chain, findings in keeping with a diagnosis of plasmacytoma of the thyroid. In addition, there was kappa monotypic staining of the lymphoid follicles and absence of tangible body macrophages, indicating the presence of a follicular lymphoma derived from a separate cell line from the plasmacytoma.     

Primary plasmacytoma of the thyroid: A case report and comparative literature study between Western nations and Japan

A 52 year old man presented with primary thyroid plasmacytoma. The patient was initially followed up for thyroid dysfunction. The histological examination of the removed thyroid revealed a proliferation of mature and immature plasma cells indicative of plasmacytoma with Hashimoto's disease. After radiotherapy (40 Gy) to the neck following right hemi-thyroidectomy, the patient is currently alive and well 3 years after diagnosis without any evidence of tumor. The immunohistological examination of the removed thyroid showed monoclonality for immunoglobulin G-Kapa light chains. Sixty-six literature cases of primary thyroid plasmacytoma were reviewed and comparison of the clinical and histological characteristics between Japanese and Western cases noted. The incidence of the patients with antithyroid antibody was significantly lower (P < 0.01) in Western patients (42.9%) than in Japanese patients (87.5%). The higher incidence of thyroid dysfunction and Hashimoto's disease in Japan in comparison with Western nations was well reflected in the incidence of antithyroid antibody.     

Incidence of neoplasia in Hashimoto's thyroiditis: A fine-needle aspiration study

There is a recognized association between Hashimoto's thyroiditis (HT) and thyroid neoplasms. We reviewed fine-needle aspirations (FNAs) from 90 patients with HT to assess the contribution of this procedure. For seven patients, FNA showed HT and follicular neoplasm (n = 6) or HT and papillary carcinoma (n = 1). Eighteen patients underwent thyroid resection. Three patients had follicular adenomas which were not detected by FNA, one patient had papillary carcinoma confirmed, and six patients with follicular neoplasm by FNA were negative for tumor. Thus, 4% of our patients had confirmed neoplasms, an incidence lower than usually reported. One reason for the lower rate of neoplasia in our series was misinterpretation of follicular neoplasia in the background of HT. The cytologic changes in the hyperplastic follicular and metaplastic oncocytic epithelium are similar to those seen in follicular neoplasm. Our study suggests that these processes may be indistinguishable, and thus, in the presence of HT, the diagnosis of follicular neoplasm probably should not be rendered. Diagn Cytopathol 1996;14:38–42. © 1996 Wiley-Liss, Inc.     

Mutations of the BRAF gene in papillary thyroid carcinoma and in Hashimoto's thyroiditis

The purpose of the present study was to investigate the frequency of BRAF mutations in human papillary thyroid carcinoma (PTC) and Hashimoto's thyroiditis (HT) and to evaluate the association of the BRAF mutation with the clinicopathological features of both of these thyroid disorders. A total of 51 PTC with no HT, 28 PTC with HT and 27 HT with no PTC were evaluated using DNA extracted from paraffin-embedded specimens. BRAF mutations were analyzed by direct DNA sequencing of the polymerase chain reaction (PCR)-amplified exon 15. The BRAF missense mutation at codon 599 (T1796A) was present in 46 of 51 PTC (90%) with no HT, 18 of 28 PTC (64%) with HT, four of 28 HT (14%) with PTC, and zero of 27 HT with no PTC. The BRAF mutation at codon 600 (A1798G) was not detected in any case. Clinicopathological examination of 106 patients with either PTC or HT showed that the BRAF mutation was significantly correlated with patient age. These data indicate that the BRAF mutation is associated with a valuable biological property of PTC and may participate in the pathogenesis of PTC arising in HT. These results indicate that the detection of the BRAF mutation in HT can be helpful for prediction of progress to PTC.     

Incidental langerhans cell histiocytosis of thyroid: case report and review of the literature

We report a case of a 42-yr-old woman with Langerhans cell histiocytosis (LCH) confined to the thyroid and associated with lymphocytic thyroiditis and a papillary microcarcinoma. This patient remains free of symptoms 14 mo after surgery. Thyroid LCH is rare. In children, it usually occurs as part of a multisystemic disease, whereas it is usually exclusive in adults. Isolated thyroid LCH is frequently associated with another thyroid disease, especially lymphocytic thyroiditis, suggesting that it is a reactive process rather than a neoplastic proliferation. The prognosis of isolated thyroid LCH is good. However, because it can rarely precede or reveal a multisystemic disease, additional investigations as well as a prolonged follow-up are justified.     

Subisthmic accessory thyroid gland in man: A case report and a review of thyroid anomalies

Morphological variations of the thyroid gland are common and generally occur superior to the gland, reflecting its developmental origin. In this report we describe an accessory lobe located inferior to both lateral lobes and the isthmus. The accessory lobe was supplied by a branch of the right inferior thyroid artery and its vein drained via the plexus thyroideus impar. A discussion of thyroid anomalies is presented and a system for classifying variations of thyroid anatomy is proposed. Clin. Anat. 10:341–344, 1997. © 1997 Wiley-Liss, Inc.     

Thyroid peroxidase autoantibody epitopic ‘fingerprints’ in juvenile Hashimoto's thyroiditis: evidence for conservation over time and in families

In Hashimoto's thyroiditis, the humoral component is manifest by autoantibodies to thyroid peroxidase (TPO). Epitopic ‘fingerprinting’ of polyclonal serum TPO autoantibodies has been facilitated by the molecular cloning and expression as Fab of a repertoire of human TPO autoantibody genes. To investigate whether TPO autoantibody fingerprints are (i) stable over long periods of time (~15 years), and (ii) inherited, we studied a cohort of nine patients with juvenile Hashimoto’s thyroiditis and 21 first degree relatives of four of these patients. Fingerprints were determined by competition between four selected Fab and serum autoantibodies for binding to ¹²⁵I-TPO. Regardless of titre, the TPO epitopic profile was stable in 10/12 individuals whose TPO autoantibody levels were sufficient for analysis on two or three occasions over 12–15 years. Although the TPO epitopic fingerprint profiles in two families raised the possibility of inheritance, overall the data from all four families did not reveal an obvious pattern of genetic control. In no family was the TPO epitopic fingerprint associated with HLA A, B or DR. In conclusion, TPO autoantibody epitopic fingerprints are frequently conserved over many years. Studies on additional families are necessary to establish whether or not the epitopic profiles of TPO autoantibodies are inherited.     

Difficulties in diagnosis of Riedel's thyroiditis on aspiration cytology: A case report and brief review of the literature

Riedel's thyroiditis (RT) is a rare disorder characterized by extensive fibrosis extending to the extrathyroidal tissues. An elderly male presented with diffuse moderate thyromegaly and hoarseness of voice for two years. Radiology showed extrathyroidal extension around trachea with compression and deviation suggestive of malignancy. Thyroid was hard and non tender. Ultrasound guided Fine Needle Aspiration (FNA) from multiple foci on both sides using thinner needle yielded moderately cellularity showing follicular cells, lymphoplasmacytic infiltrate, scant colloid and fibrous tissue fragments. Hurthle cells were absent. Adiagnosis of chronic thyroiditis was given with possibility of RT in view of clinical and radiological findings. A core biopsy showed similar picture as cytology. Guided FNA from multiple foci using thinner needle helped to obtain adequate material allowing a confident diagnosis. This case adds to the meagre literature available on the cytologic diagnosis of RT and highlights the diagnostic challenge due to suspicious radiology findings.     

Medullary thyroid carcinoma co‐existent with Hashimoto's thyroiditis diagnosed by a comprehensive cytological approach

Fine‐needle aspiration cytology (FNAC) is a preliminary test for the diagnosis of thyroid lesions. We hereby report a rare case of medullary thyroid carcinoma (MTC) co‐existing with Hashimoto's thyroiditis (HT). This case was substantiated with ancillary tests on cytology material to give a novel insight. A 60‐year‐old female presented clinically with diffuse enlargement of the thyroid, and right‐side nodule on ultrasonography. FNAC of the isthmic area showed features of HT, while cytology of right‐side nodule displayed sheets of plasmacytoid cells and frequent scattered large bizarre and pleomorphic cells, lymphoglandular bodies and pale eosinophilic material. The differential diagnosis of MTC with co‐existent HT or high‐grade lymphoma was considered. To establish the diagnosis, serum calcitonin and ancillary studies on aspirated material were carried out. High serum calcitonin (7251 pg/mL), Congophilia on smears, and CD 45?ve; CD56+ve expression of tumor cells on flowcytometric analysis established the diagnosis of MTC over lymphoma. This diagnosis was further confirmed upon histopathology. Ancillary studies on aspirated material established the diagnosis of MTC and excluded the diagnosis of lymphoma. Establishing the correct diagnosis was cardinal in such a scenario as these diseases have extremely diverse management.     

Follicular thyroid lesions coexisting with Hashimoto's thyroiditis: incidence and possible sources of diagnostic errors

Our objectives were to study the types and incidence of thyroid follicular lesions coexisting with Hashimoto's thyroiditis (HT), the pitfalls in their cytodiagnosis, and the effect on management. All cases of HT diagnosed by fine-needle aspiration (FNA) and/or histology over a 7-yr period were retrospectively studied. HT coexisted with follicular adenoma (FA) in 6 cases, follicular variant of papillary carcinoma (FVPC) in 1 case, and goitrous nodule (GN) in 2 cases. The overall incidence rates of thyroid neoplasm and goitrous nodules coexistent with HT were 15% and 3.5%, respectively. A preoperative FNA diagnosis was available in 10 histologically proven cases of HT. A false-positive diagnosis of follicular neoplasm (FN) that led to unnecessary thyroidectomies was given in 3 cases. In 2 of these, the cytological diagnosis was HT with the possibility of coexisting FN, and in the third case, the cytological finding of HT was misinterpreted as FN. The main causes of these diagnostic pitfalls were the presence of hyperplastic follicular cells with nuclear pleomorphism, a paucity of lymphoid cells in burned-out HT, and lack of ones exposure. Nuclear pleomorphism was observed in none of the follicular adenomas. FNA diagnosed accurately the coexisting lesions in 6 cases; 3 FA, 1 FVPC, and 2 GN, but it did not sample HT. In one case, FNA diagnosed correctly both HT and the coexisting FA. Therefore, the presence of a coexistent neoplasm or goitrous nodule reduced the chances of sampling HT by 85.7%, with no false-negative results. Indeed, aspiration on and around the thyroid nodule helps in sampling HT. However, HT may dominate the smear and obscure neoplasia. This can be avoided if the procedure is performed by the pathologist and the aspiration is done on the nodule only. The overlapping cytological features of FN and HT were the main causes of false-positive results. This can be reduced by avoiding the diagnosis of FN in the presence of follicular-cell pleomorphism and/or moderate to excessive numbers of lymphoid cells, provided proper aspiration technique is maintained.     

Fine-needle aspiration of subacute granulomatous thyroiditis (De Quervain's thyroiditis): A clinico-cytologic review of 36 cases

Although subacute granulomatous thyroiditis (SGT) is usually diagnosed clinically, there are other thyroid conditions that must be ruled out. This task is achieved by means of fine-needle aspiration (FNA). In retrospect, the clinical and cytologic findings seen in 36 SGT cases are reassessed with a view to deciding which findings are most reliable for reaching a confident cytologic diagnosis. These are: the simultaneous presence in the same aspirate of the following cells: 1) follicular cells with intravacuolar granules and/or plump transformed follicular cells; 2) epithelioid granulomas; 3) multinucleated giant cells; 4) an acute and chronic inflammatory dirty background; 5) the absence of the following cells: fire-flare cells, hypertrophic follicular cells, oncocytic cells, and transformed lymphocytes. The absence of one or more of these requirements does not exclude SGT but does increase the number of thyroid conditions that come into the differential diagnosis. In these cases, it is essential to review clinical data carefully and to submit the patient to a close clinical and FNA follow-up. Diagn. Cytopathol. 16:214–220, 1997. © 1997 Wiley-Liss, Inc.     

Cytological features of warthin‐like papillary thyroid carcinoma: A case report with review of previous cytology cases

Warthin‐like papillary thyroid carcinoma (WLPTC) is a rare morphological variant of papillary thyroid carcinoma which mimics various benign and malignant lesions on thyroid aspiration cytology. As correct cytological diagnosis is the cornerstone for appropriate patient management, awareness of the salient cytomorphological characteristics of this tumor is essential. Here, we present cytological features of a case of WLPTC along with discussion of the common differential diagnoses and a brief review of the literature to ascertain the most consistent cytological findings of WLPTC. The present case also harboured BRAFV600E mutation which is the commonest molecular alteration seen in WLPTC.     

Intra-thyroid thyroglossal duct cyst: a case report and review of literature

Thyroglossal duct cyst is the most common congenital cyst in the head and neck, which is defined usually occurring in children. However, intra-thyroid thyroglossal duct cyst in an adult is unusually found. Here we describe a case of a 45-year-old woman who was found neck mass along the midline for 5 years. During the surgery we found a separated nodule in the left inferior pole of the thyroid. Surprisingly the diagnosis of the nodule was confirmed by pathology and histological examination demonstrating that it was the thyroglossal duct cyst. Intra-thyroid thyroglossal duct cyst in an adult is a rare finding, with few cases reported. For it is generally thought that any thyroid tissue found in the lateral aspect of the neck may indicate metastatic deposits from well-differentiated thyroid carcinoma. Although pathogenesis of an alone thyroglossal duct cyst in the left inferior pole of the thyroid remains unknown, our case could suggest thyroglossal duct cyst should not be excluded in the differential diagnosis of lateral neck masses especially when it simulates nodules in the thyroid.     

Plasma cell granuloma of the thyroid gland mimicking carcinoma: a case report and review of the literature

Plasma cell granulomas (PCG) are rare tumor-like lesions consisting of sheets of polyclonal plasma cells admixed with numerous lymphocytes and other inflammatory cells surrounded by fibrous stroma. They usually appear in the lung, but involvement of diverse extrapulmonal sites has been described. PCGs occurring in the thyroid are very uncommon. Since 1981, only 11 cases have been described in the English literature. Here, we present the case of a 50-year-old Arabic man who noticed an enlargement of his thyroid gland during the previous 2 years, and he developed swallowing disturbances and a feeling of narrowness in the neck. A nearly total resection of the thyroid gland was made because of clinical suspicion of carcinoma. On histologic examination, PCG of the thyroid associated with Hashimoto's thyroiditis (HT) was diagnosed. This is the first case in which molecular pathological analyses for EBV and HHV8 DNA were made. As these were negative, distinct etiological features were suggested.     

Pleural‐based neuroblastoma‐like schwannoma: A case report with cytologic findings and review of literature

We report a rare case of a 45‐year‐old African American woman with Neuroblastoma‐like Schwannoma (Neurilemmoma) occurring in the posterior mediastinum as a pleural‐based mass noted on computed tomography (CT) scan. A CT‐guided core biopsy of the mass was performed and core biopsy imprints were prepared during the procedure. A Diff‐Quik stain was performed for on‐site evaluation of specimen adequacy. The hematoxylin and eosin (H&E) staining was evaluated subsequently. Immunohistochemistry panels were applied to the same specimen. The cytologic findings of the core biopsy imprints showed hypercellular smears with a predominance of small cells with atypical features including hyperchromatic, round nuclei and occasional nucleoli. Neurocytic rosettes were particularly appreciated on H&E stain. The immunohistochemical results exhibited strong and diffuse immunoreactivity for S‐100 and vimentin. This case enriches the cytopathology literature by providing awareness of this tumor presenting as a posterior mediastinal mass. Diagn. Cytopathol. 2015;43:650–653. © 2015 Wiley Periodicals, Inc.