Asymptomatic intrathyroidal parathyroid adenoma. Report of a case with a cytologic differential diagnosis including thyroid neoplasms

BACKGROUND: Intrathyroidal parathyroid neoplasms (IPNs) are uncommon tumors with an indolent clinical course. When asymptomatic, they can be incorrectly diagnosed as thyroid neoplasms on fine needle aspiration biopsy (FNAB), leading to inappropriate surgical treatment. CASE: A case of unsuspected IPN occurred in which the cytologic picture mimicked that of a thyroid neoplasm. The histologic specimen of the total thyroidectomy showed 2 adjacent intrathyroidal nodules morphologically and immunohistochemically corresponding to a parathyroid adenoma. CONCLUSION: The incidence of IPN remains controversial, especially in asymptomatic patients. On FNAB it is a possible cause of inappropriate surgery for a suspicious thyroid neoplasm (follicular or medullary carcinoma). Immunostaining for parathormone on the cytologic smear is valuable in establishing the correct preoperative diagnosis when the morphologic features are strongly suggestive of IPN.     

Cytologic diagnosis of a medullary carcinoma of the thyroid by Sevier-Munger silver staining and calcitonin immunocytochemistry

A medullary carcinoma of the thyroid was preoperatively diagnosed on ultrasonically guided fine needle aspiration biopsies. After cytocentrifugation, the tumor cells displayed a dense cytoplasmic silver granulation with the Sevier-Munger technique when applied to air-dried or acetone-ethanol-fixed samples and an obvious calcitonin immunoreactivity after fixation in Bouin's fluid. These methods may prove useful in the identification of nonpalpable metastases and recurrences of medullary carcinomas of the thyroid, especially since the cytologic typing of medullary thyroid carcinoma cells may be difficult with routine stainings.     

Fine needle aspiration biopsy of neuroendocrine breast carcinoma metastatic to the thyroid. A case report

BACKGROUND: Tumors showing neuroendocrine differentiation arise in a wide range of organs, and metastatic neuroendocrine tumors may be difficult to differentiate from primary tumors. This report describes an unusual case of metastatic breast carcinoma with neuroendocrine differentiation that presented as a solitary thyroid nodule. The diagnosis was made by fine needle aspiration biopsy (FNAB). CASE: A 52-year-old woman presented with a thyroid nodule and bilateral enlarged supraclavicular fossa lymph nodes. FNAB revealed a neuroendocrine carcinoma. Further questioning revealed that the patient had had a breast carcinoma resected eight years previously. The diagnosis of metastatic neuroendocrine breast carcinoma was established by immunocytochemistry. The patient received antiestrogen therapy but subsequently developed skeletal metastases. CONCLUSION: Neuroendocrine carcinomas from various sites show similar cytologic features. In this case, a diagnosis of breast carcinoma metastatic to the thyroid was suggested by the clinical history and confirmed by FNAB with immunocytochemistry.     

Intranuclear vacuoles in nonpapillary carcinoma of the thyroid. A report of three cases

Three cases of nonpapillary carcinoma of the thyroid are reported in which intranuclear vacuoles or (pseudo)inclusions were observed in fine needle aspiration smears. Two of the cases had medullary carcinoma; one had a poorly differentiated follicular carcinoma. The cytologic, histologic and ultrastructural appearances of intranuclear vacuoles and of the so-called ground-glass nuclei of papillary carcinoma are described, and the diagnostic significance of these findings is discussed briefly. Intranuclear vacuoles are distinct and different from ground-glass nuclei.     

Fine needle aspiration cytology of mixed medullary-follicular thyroid carcinoma: a case report

BACKGROUND: Mixed medullary-follicular thyroid carcinoma (MMFTC) is a rare tumor that has been regarded as a clinicopathologic variant of medullary thyroid carcinoma. MMFTC represents a diagnostic challenge by fine needle aspiration cytology (FNAC). CASE: A 77-year-old woman had a palpable mass on the left side of the neck. It was diagnosed as follicular neoplasm by FNAC; she underwent total thyroidectomy. Pathology revealed follicular carcinoma. Radioactive iodine was administered. An enlarging mass was present in the left mandible later. FNAC showed suspicious follicular neoplasm with predominance of oncocytic cells. Pathology revealed follicular carcinoma with parafollicular cell differentiation. Immunohistochemical analysis demonstrated positive status for thyroglobulin and calcitonin. Simultaneous expression of thyroglobulin and calcitonin within the same neoplastic cell was considered. She underwent several courses of radioactive iodine therapy without significant effect. Interestingly, her serum calcitonin level was not elevated. CONCLUSION: Coexpression of thyroglobulin and calcitonin in the same cell is very rare. The component of medullary carcinoma should be considered when encountering an atypical thyroid carcinoma with predominance of cells showing oncocytic changes on FNAC and with clinically poor response to conventional treatment. Immunohistochemistry and pathologic analyses are helpful to confirm the diagnosis, especially in the absence of elevated serum calcitonin level.     

Fine needle aspiration of poorly differentiated oxyphilic (Hürthle cell) thyroid carcinoma: a case report

BACKGROUND: Poorly differentiated oxyphilic (Hürthle cell) carcinomas are a more recently described variant of poorly differentiated thyroid carcinoma and are characterized by a prominent Hürthle cell component in a solid or trabecular arrangement. Clinically, poorly differentiated oxyphilic carcinomas behave more aggressively as compared to classic Hürthle cell carcinomas, which have a predominantly follicular pattern. Although the histology of these rare thyroid tumors has been reported in the literature, the cytologic features on fine needle aspiration biopsy have not been described before. CASE: A 73-year-old man with a long history of radioactive iodine and levothyroxine therapy for multinodular goiter presented with a painful, rapidly expanding, 6-cm, left thyroid mass with aggressive radiologic features. Fine needle aspiration biopsy of the mass yielded extremely cellular smears with a dual population of medium-sized follicular cells and numerous Hürthle cells. Subsequent thyroidectomy confirmed the malignant nature of this Hürthle cell-rich tumor, warranting a diagnosis of poorly differentiated oxyphilic (Hürthle cell) thyroid carcinoma. CONCULSION: Poorly differentiated oxyphilic thyroid carcinoma is an aggressive variant of Hürthle cell carcinomas and must enter the differential diagnosis when fine needle aspiration biopsy of a radiologically aggressive thyroid mass yields extremely hypercellular smears with a prominent Hürthle cell component.     

Isolated carcinoid tumor metastatic to the thyroid gland: report of a case initially diagnosed by fine needle aspiration cytology

BACKGROUND: Neuroendocrine tumor metastatic to the thyroid gland is rare and may be difficult to differentiate from primary thyroid neuroendocrine tumors, such as medullary thyroid carcinoma (M/ITC). This report describes an unusual case of bronchial carcinoid metastatic to the thyroid diagnosed by fine needle aspiration cytology (FNAC). CASE: A 42-year-old woman with an undiagnosed bronchial carcinoid tumor presented to our clinic with a solitary nodule in the thyroid gland. FNAC of the nodule showed loosely cohesive groups of cuboidal tumor cells with scant, slightly granular cytoplasm; centrally located nuclei with a coarsely granular, salt-and-pepper chromatin pattern and inconspicuous nucleoli. Immunocytochemically the tumor cells were positive for neuron-specific enolase, chromogranin and synaptophysin and negative for thyroglobulin, calcitonin and carcinoembryonic antigen. The cytologic diagnosis of a metastatic neuroendocrine carcinoma was confirmed histologically. CONCLUSION: Metastasis to the thyroid gland may pose a diagnostic problem, particularly with tumors of neuroendocrine origin, as these have similar cytologic features in various organs. The correct preoperative cytologic diagnosis of metastatic carcinoid tumor in patients without a prior history of cancer and differential diagnosis with MTC are crucial because prognosis, workup and treatment are different in each.     

Cytologic features of solitary fibrous tumor of the parotid gland. A case report

BACKGROUND: Solitary fibrous tumor (SFT) is a rare neoplasm that most commonly involves the pleura but is increasingly recognized at other locations, including lung, liver, thyroid and parotid glands, with only a few reports describing its cytologic features. CASE: The fine needle aspiration biopsy (FNAB) features of an SFT located in the left parotid gland of a 34-year-old woman were compared to the histologic and immunohistochemical aspects of the lesion. CONCLUSION: This case confirms that SFT has distinct cytomorphologic features and that FNAB can be helpful in its diagnosis.     

Transthoracic fine needle aspiration biopsy in pulmonary lesions. Updated results

An investigation was carried out on 271 patients who underwent transthoracic fine needle aspiration biopsy ( FNAB ) for suspected pulmonary lesions in a four-year period; 80% of them had a malignant tumor. The histologic control of the cytologic diagnoses made on the transthoracic FNAB was possible in over 50% of the cases. The sensitivity and predictive value for positive results were, respectively, 0.890 and 0.995, whereas the typing accuracy verified in 58 cases on the surgical specimen was 0.76. The comparison of the data obtained from the most recent case material with that of early observations confirmed the high sensitivity of transthoracic FNAB in the detection and characterization of malignant lesions in the lungs. The sensitivity was almost identical for primary tumors, 0.90, and metastatic disease, 0.88. Furthermore, over the years the data showed an improvement in the results due to the experience gained, the combined use of cytology and histology and the application of histochemical methods. More sophisticated methods, such as immunocytochemistry and electron microscopy, were essential to the final diagnosis in only a few cases.     

Cytopathologic features of pituitary carcinoma with cervical vertebral bone metastasis: a case report

BACKGROUND: Pituitary carcinomas are extremely rare tumors of the adenohypophysis. The presence of craniospinal and/or systemic extracranial metastases is the only reliable criterion for the diagnosis of pituitary carcinoma. To date, only 2 cases have been reported correctly by fine needle aspiration biopsy (FNAB). We present an additional case of pituitary carcinoma with FNAB features. CASE: A 60-year-old woman presented with clinical features of Cushing's disease and a pituitary tumor. She underwent transsphenoidal resection of the tumor. The initial diagnosis was an adrenocorticotrophic hormone (ACTH)-producing invasive pituitary adenoma. The patient presented again with neck pain 6 years after the operation. Magnetic resonance imaging revealed metastatic tumor masses at the level of C5-C6 of the cervical vertebrae. Intraoperative fine needle aspiration and incomplete excision of metastatic tumors were performed. Cytologically, tumor cells were composed of a combination of loose groups and single cells. Neoplastic cells had a relatively monotonous appearance and displayed characteristic neuroendocrine tumor features. Immunocytochemistry from cell block sections revealed AE1/ AE3, synaptophysin chromogranin A and ACTH positivity in the tumor cells. CONCLUSION: Pituitary carcinoma with extracranial systemic metastases demonstrates typical neuroendocrine features on fine needle aspiration. In the differential diagnosis, metastatic neuroendocrine carcinomas should be kept in mind. In the absence of sufficient clinical data, these 2 entities cannot be distinguished correctly through the cytologic features.     

Intracytoplasmic lumina in medullary carcinoma of the thyroid gland. Report of a case with cytologic and immunocytochemical features

BACKGROUND: Intracytoplasmic lumina (ICL) have been observed frequently in breast carcinoma cells. However, they are extremely rare in thyroid gland tumors. We encountered a medullary carcinoma of the thyroid (MCT) with ICL and present a case with cytologic, immunocytochemical and ultrastructural features. CASE: A 15-year-old female was admitted with a left thyroid mass. Ultrasound examination revealed a well-defined tumor in the left lobe of the thyroid. Fine needle aspiration cytology showed mainly dispersed spindle cells with oval nuclei and some polymorphic or triangular tumor cells. The tumor cells containing ICL were noted at high magnification. The ICL contained sparse microvilli and abundant granular material with dense, round bodies on ultrastructural sections. Immunocytochemically, these tumor cells were positive for calcitonin and carcinoembryonic antigen (CEA). Moreover, CEA was recognized in the ICL with immunocytochemical staining. All tumor cells were negative for thyroglobulin. Pathologic examination confirmed the diagnosis of medullary carcinoma of the thyroid gland. CONCLUSION: MCT can include ICL with granular material containing CEA.     

Nonaspiration-needle smear preparations of pulmonary lesions. A comparison of cytology and histology

Material for cytologic smears was obtained from pulmonary lesions in 146 patients at the Ohio State University between 1979 and 1984 using Rotex or Lee screw needles. Corresponding histologic specimens were available for comparison in 77 of these cases. Diagnoses of malignant neoplasms made by cytologic evaluation (55 cases) were confirmed by the corresponding histologic specimens in 93% of those cases. Possible explanations for the cytologic false-positive diagnoses of malignancy are presented. Correlations between the cytologic and histologic diagnoses of the morphologic type of tumor were 100% for adenocarcinoma, 75% for squamous-cell carcinoma and 20% for large-cell undifferentiated carcinoma. The correlation was 100% for small-cell carcinoma when the histology specimen represented the tumor. Nonneoplastic benign lesions diagnosed cytologically had corresponding benign histologic diagnoses in 94% of the cases. These results compare favorably with those reported for other fine needle aspiration studies of pulmonary lesions. The advantages of using Rotex needles as compared to fine needle aspiration are discussed.     

Papillary carcinoma of the thyroid occurring during pregnancy. Report of a case diagnosed by fine needle aspiration cytology

A case of papillary carcinoma of the thyroid gland occurring during pregnancy in a 29-year-old woman is described. The enlarged thyroid nodule was first detected at 10 weeks of gestation; fine needle aspiration (FNA) of the nodule showed no cytologic evidence of malignancy. Repeat FNA at 30 weeks of gestation produced inadequate material for diagnosis. A final FNA at 38 weeks of gestation showed classic cytologic features of papillary carcinoma, including papillary structures, grooved nuclei and intranuclear cytoplasmic inclusions. After delivery, the patient was treated with total thyroidectomy and cervical lymph node dissection. The enlargement of the nodule in this case during the course of the pregnancy suggests a relationship between pregnancy and the malignant development of thyroid nodules; this is discussed along with the utility of FNA cytology for diagnosing thyroid cancers during pregnancy.     

Thyroid papillary microcarcinoma. Is it really a pitfall of fine needle aspiration cytology?

OBJECTIVE: To assess the role of fine needle aspiration (FNA) of the thyroid in the diagnosis of papillary microcarcinoma. STUDY DESIGN: Eight cases of papillary microcarcinoma were diagnosed by fine needle aspiration. On histologic examination they were found to be adjacent to larger nodules of interest. The microcarcinomas were inadvertently sampled when sampling the larger, dominant nodules. RESULTS: None of the eight dominant nodules were papillary carcinoma; seven were benign lesions, and one was an angioinvasive Hürthle cell carcinoma. In three cases the microcarcinomas were situated within the capsule of a hyperplastic nodule. On histologic examination, five cases had multifocal microcarcinomas, with one case having multiple lymph node metastases. Based on the clinical findings and morphologic features, there were no definitive cytologic findings that could distinguish between "incidental" microcarcinoma and clinically significant papillary carcinoma. CONCLUSION: The detection of microcarcinoma by FNA should not be considered a false positive finding since the exact nature of the lesion cannot be determined until complete histologic evaluation reveals it to be truly incidental and clinically insignificant.     

Cytologic features of poorly differentiated "insular" carcinoma of the thyroid. A case report.

A case of poorly differentiated "insular" carcinoma of the thyroid is presented. Fine needle aspiration cytology suggested the differential diagnosis of poorly differentiated carcinoma versus anaplastic carcinoma. Histologic examination of the resected specimen confirmed the diagnosis of insular carcinoma. The cytologic features of this uncommon primary thyroid malignancy are described and discussed with reference to the literature.     

Macrofollicular encapsulated variant of papillary thyroid carcinoma as a potential pitfall in histologic and cytologic diagnosis. A report of three cases

BACKGROUND: Macrofollicular encapsulated papillary carcinoma (MEPC) is a variant of papillary carcinoma with a favorable clinical course. Its characteristic histologic pattern could be mistaken for that of an adenoma or hyperplastic nodule. Fine needle aspiration of this neoplasm may not show the particular nuclear features of papillary carcinoma, so the cytologic diagnosis may be benign. CASE REPORTS: Three paradigmatic cases of MEPC with different histologic patterns, diagnosed as a follicular neoplasm using fine needle aspiration biopsy (FNAB) are described. Preoperative cytology showed scattered clusters of thyrocytes with prominent nuclear pleomorphism and irregularities and focal oxyphilic changes mixed with colloid and aggregates of typical thyrocytes. The histologic picture exhibits small, neoplastic foci showing a microfollicular structure within an encapsulated neoplasm with a macrofollicular pattern. In microfollicular areas obvious nuclear pseudoinclusions were seldom observed. CONCLUSION: MEPC represents a challenging tumor subtype that infrequently shows the pathognomonic cytologic characteristics of papillary carcinoma, and therefore it is much more difficult to diagnose with a FNAB. Nuclear pleomorphism and irregularity of the nuclear membrane of thyrocytes are clues to this variant, although in some cases a clear-cut preoperative diagnosis cannot be made.     

Simultaneous occurrence of medullary and papillary carcinoma of the thyroid gland identified by fine needle aspiration. A case report

BACKGROUND: Fine needle aspiration (FNA) diagnosis of simultaneous medullary and papillary thyroid carcinoma in independent thyroid lobes is exceedingly rare. CASE: A 36-year-old female presented with a one-month history of dysphagia. Thyroid ultrasound revealed a multinodular goiter. She was clinically and biochemically euthyroid. FNA of the right thyroid nodule was consistent with medullary carcinoma, and FNA of the left thyroid lobe was consistent with papillary carcinoma. Immunohistochemistry revealed strong calcitonin and CEA positivity in the right lobe and lack of staining in the left lobe. Conversely, staining for thyroglobulin was negative on the right lobe and positive on the left lobe. CONCLUSION: The patient developed tumors in separate lobes of the thyroid. Immunoreactivity of calcitonin, CEA and thyroglobulin made a sharp distinction between the two tumors. Therefore, we conclude that these tumors were not linked by either embryology or genetics.     

Spleen metastasis from thyroid carcinoma. Report of a case with diagnosis by fine needle aspiration cytology

BACKGROUND: Lymphoreticular malignancies are the most common neoplasms involving the spleen. Metastasis can be caused by direct invasion from surrounding tumors or from hematogenous spread. Spleen metastases from thyroid carcinoma are unusual, and only 1 case has been reported; none have been diagnosed by fine needle aspiration cytology (FNAC). CASE: A 75-year-old female was diagnosed 6 months earlier with a poorly differentiated thyroid carcinoma with wide lymphatic and vascular invasion. Abdominal computed tomography (CT) and magnetic resonance imaging showed several spleen nodules. FNAC was performed under CT guidance. Cytologic examination showed atypical epithelial cells with thyroidal characteristics. CONCLUSION: This case had the cytologic findings of a poorly differentiated carcinoma of the thyroid metastatic to spleen. We confirmed the rarity of this pathology and the efficacy of splenic FNAC in the diagnosis.     

Primary cytodiagnosis of dually differentiated lung cancer by transthoracic fine needle aspiration

The cytologic features are described in a case of squamous cell carcinoma and small cell cancer of the lung concurrently diagnosed by a single transthoracic fine needle aspiration specimen. The value of diagnostic cytology in the detection of dually differentiated lung malignancies is discussed, and the importance of identifying the small cell component in order to direct appropriate therapy is emphasized.     

Malignant teratoma of the thyroid with predominantly neuroepithelial differentiation. Fine needle aspiration cytologic, histologic and immunocytochemical features of a case

BACKGROUND: Teratoma of the thyroid in adults is extremely rare, and most are malignant. Only nine cases have been adequately documented in the English-language literature, and there are no reports detailing the fine needle aspiration (FNA) cytologic characteristics. CASE: A 32-year-old female presented with a left-sided nodular thyroid mass with left cervical lymphadenopathy. FNA cytology of the thyroid and lymph nodes was done. The cytologic and immunocytochemical features were that of a small round cell tumor with neuroepithelial (NE) differentiation, metastasizing to the cervical nodes. Microscopic study of the thyroidectomy specimen showed a tumor showing an NE pattern with occasional islands of squamous and cuboidal epithelium, leading to a diagnosis of malignant teratoma. CONCLUSION: Knowledge of FNA cytologic features of rare but highly malignant lesions like thyroid teratomas allow early recognition so that suitable and possibly aggressive treatment protocols can be adopted in the hope of prolonging survival.