Columnar cell variant of papillary thyroid carcinoma. Report of a case with cytologic findings

BACKGROUND: The columnar and tall cell variants of papillary thyroid carcinoma (PTC) are uncommon variants and have generally been regarded as more aggressive forms in comparison to the more common classic papillary and follicular subtypes. Cytologic diagnosis of these rare variants is elusive since the characteristic nuclear features of the usual papillary thyroid carcinoma are very often absent or inconspicuous. We present a case of the columnar cell variant of PTC in a young woman that demonstrates the diagnostic challenge. CASE: A 24-year-old woman presented with a solitary, 3-cm mass in the left aspect of the thyroid. The aspirate consisted of a moderately cellular sampling of sheets, papillary clusters and microfollicles of cells with oval nuclei and uniform, finely granular chromatin. These cells were arranged in a peudostratified manner around well-defined fibrovascular cores. There were no intranuclear inclusions or well-defined nuclear grooves in the cells of the aspirate. There was also absence of colloid despite the presence of well-formed follicles. The resected thyroid revealed a columnar cell variant of PTC. CONCLUSION: The cytologic features of columnar cell-type PTC are at variance with those of classic PTC and are elusive in fine needle aspiration cytology. It is the lack of classic cytologic features of PTC that is distinctly apparent, yet it is the monomorphism of cells in the aspirate, their papillary configuration and their pseudostratification in well-formed fibrovascular cores that are the keys to the diagnosis. Immunohistochemical staining to rule out other thyroid neoplasms can be performed to aid in the diagnosis.     

Cytopathology of the tall cell variant of thyroid papillary carcinoma.

The tall cell variant of thyroid papillary carcinoma differs from classic papillary carcinoma in its more aggressive clinical behavior, cell type (columnar amphophilic to oxyphilic) and higher frequency of stromal lymphoid infiltrate. A retrospective study of three such cases was made, with an emphasis given to the utility of fine needle aspiration cytology in their identification. Aspirates revealed papillary fronds and cyanophilic and oxyphilic neoplastic cells with a high proportion of nuclear grooves and cytoplasmic inclusions. These nuclear details allowed a specific diagnosis of papillary carcinoma with oxyphil cells as compared to oxyphilic cell follicular tumors. Smears from two cases showed, in addition, lymphoid cells and multinucleate giant cells. In them a diagnosis of coexisting Hashimoto's disease, granulomatous thyroiditis or inflammatory tumor stroma could not be excluded cytologically.     

Morphologic spectrum of papillary carcinoma of the thyroid: role of cytology in identifying the variants

OBJECTIVE: To evaluate the efficacy of fine needle aspiration cytology (FNAC) in the diagnosis of morphologic variants of papillary carcinoma of the thyroid (PCT) and to determine the reasons for misdiagnosis in discrepant cases on cytology. STUDY DESIGN: Fine needle aspiration smears from 158 histologically proven cases of PCT were blindly reviewed and an attempt made to subclassify them into different variants on the basis of various architectural and morphologic features. Cytohistologic correlation was performed to assess the efficacy of cytology in correctly identifying these variants. RESULTS: In cases with satisfactory aspirates, the diagnosis of papillary carcinoma was correctly made in 112 of 139 (80.5%) histologically proven cases of PCT. Subclassification was correct in 87 of 96 (90.6%) cases of classic papillary carcinoma and in 25 of 43 (58.1%) of the other variants of PCT with adequate aspirates. Cytohistologic agreement was 100% in columnar cell variant (CCV) and high grade variant (HGV). Although there was overlap in the morphologic features of tall cell variant (TCV) and Hürthle cell variant, cytology correctly identified 60% and 76.4% of these cases, respectively. The accuracy of cytology was limited in diagnosing follicular variant as only 50% of these cases could be correctly typed on cytology. Nodular fascitis-like stroma and diffuse sclerosis variants could not be diagnosed on cytology. CONCLUSION: Though FNAC is of limited value in typing the variants of PCT due to overlapping morphologic features, it can provide clues to the diagnosis in certain aggressive variants such as TCV, CCV and HGV. Early diagnosis in these cases can assist clinicians with management.     

Tall cell variant of papillary carcinoma arising from a thyroglossal cyst: report of a case with diagnosis by fine needle aspiration cytology

BACKGROUND: Papillary carcinoma arising from a thyroglossal duct cyst (TDC) is the most frequent malignancy arising from this embryologic remnant of the thyroglossal duct. The preoperative fine needle aspiration cytology (FNAC) of such neoplasms has rarely been cited. Approximately 170 TDC cases have been reported in the literature worldwide, diagnosed solely on histopathology. CASE: A 63-year-old woman presented with an anterior midline neck mass of years' duration. A hypodense cyst was located at the level of the hyoid bone. FNAC of the midline neck mass showed bloody, mucoid material and numerous atypical, elongated cells. The aspirated material was reported as "papillary carcinoma possibly arising from the thyroglossal duct," and the diagnosis was confirmed by histopathologic investigation on resection material. CONCLUSION: Tall cell variant is a rare variant of papillary carcinoma and has a poor prognosis. The differential diagnosis includes Hürthle cell lesions, oncocytic papillary thyroid carcinoma and Warthin-like papillary carcinoma.     

Cribriform-morular variant of papillary thyroid carcinoma. Report of a case showing morules with peculiar nuclear clearing

BACKGROUND: There have been only 4 reported cases of cribriform-morular variant of papillary thyroid carcinoma (CMVPTC) with cytologic findings from fine needle aspiration. In these reports, the cytologic findings do not fully reflect the histologic characteristics of this entity. We report a case of CMVPTC in which a cribriform pattern without colloid and epithelial morules with peculiar nuclear clearing (PNC) were present in smears, thus fulfilling the criteria for a cytologic diagnosis of CMVPTC. Protein truncation tests for APC molecule abnormality indicated the presence of germline mutation in the patient's APC gene. CASE: A 30-year-old woman had multiple thyroid tumors. Aspiration cytology revealed a large number of round to spindle-shaped atypical-cells showing sheet-like, cribriform, follicular, whorl-like and solid, 3-dimensional arrangements. The cribriform and follicular arrangements did not contain colloid in the lumen. The powdery chromatin pattern characteristic of papillary carcinoma was not observed, but there were scattered intranuclear cytoplasmic pseudoinclusions and grooved nuclei. The nuclei of the atypical cells presenting in the whorl formations showed enlargement, thickened nuclear membranes and entirely clear contents, consistent with PNC. Hyalinelike necrotic cells were also observed in the cell clusters or in the background. Histologic and immunohistochemical findings were typical of CMVPTC. CONCLUSION: The cribriform pattern without colloid, fascicular or whorl formation of spindle cells, and morules with PNC are identifiable on cytologic smears and are sufficiently distinctive to allow a cytologic diagnosis of CMVPTC.     

Evaluating the diagnostic significance of nuclear grooves in thyroid fine needle aspirates with a semiquantitative approach

OBJECTIVE: To clarify the diagnostic significance of nuclear grooves in thyroid fine needle aspirates, to search for other associated nuclear features and to identify possible diagnostic pitfalls. STUDY DESIGN: In total, 67 fine needle aspiration cases were retrospectively reviewed for selected nuclear features, including grooves, intranuclear cytoplasmic invaginations, enlargement, pleomorphism and status of nucleoli. A semiquantitative method was used to estimate the percentage of nuclear grooves in 5 high-power fields with the most frequent nuclear grooves. RESULTS: Unequivocal intranuclear cytoplasmic invaginations were a specific diagnostic feature of papillary carcinoma. In the absence of intranuclear cytoplasmic invaginations, the presence of > or = 20% nuclear grooves was virtually diagnostic of thyroid neoplasms, predominantly papillary carcinoma. Less than 10% of nuclear grooves virtually eliminated the possibility of papillary carcinoma. However, 10-19% of nuclear grooves may be seen in papillary carcinoma and benign lesions; therefore, such cases fell into the diagnostic category of "atypical cytology" or "indeterminate" cytology. Nuclear enlargement with elongation was a readily identifiable feature usually associated with nuclear grooves. Significant pleomorphism was more commonly seen in papillary carcinoma than in benign lesions. CONCLUSION: A semiquantitative method is helpful when nuclear grooves are encountered in thyroid cytology in the absence of other diagnostic features. It can significantly improve the diagnostic specificity of nuclear grooves for papillary carcinoma.     

Primary papillary serous carcinoma of the peritoneum: report of a case with diagnosis by fine needle aspiration and immunocytochemistry

BACKGROUND: Primary papillary serous carcinoma (PPSC) of the peritoneum is a rare neoplasm, histologically indistinguishable from papillary serous carcinoma of the ovary, which diffusely involves the peritoneum but spares or minimally invades the ovaries. To the best of our knowledge, the preoperative and the fine needle aspiration diagnosis of this disorder have not been reported before. CASE: A woman developed an extensive peritoneal neoplasm 4 years after hysterectomy and bilateral salpingo-oophorectomy for benign disease. Fine needle aspiration of the tumor was performed, and the cytologic and immunocytochemical findings were consistent with papillary serous carcinoma. A diagnosis of PPSC of the peritoneum was rendered because review of all slides from previous surgical specimens showed no evidence of carcinoma and no other primary tumors were found elsewhere. CONCLUSION: Fine needle aspiration cytology coupled with immunocytochemical and clinical data allows an unequivocal preoperative diagnosis of papillary serous carcinoma (primary peritoneal or with an ovarian origin). The sole limitation to establish a primary peritoneal origin before surgery is the requirement to histologically study the ovaries. Based on this fact, the preoperative fine needle aspiration cytology diagnosis of PSCP should be restricted to oophorectomized patients.     

Papillary carcinoma of the breast. Cytologic study of nine cases.

OBJECTIVE: To study the cytologic findings of papillary breast carcinoma by fine needle aspiration. STUDY DESIGN: The study group consisted of fine needle aspiration (FNA) specimens of breast tumors from nine patients performed during the period 1988-1997. Eight were female, and one was male. The FNA results were compared with the final histologic diagnosis. RESULTS: The tumor sizes were 4-6.5 cm. The aspirations yielded a good amount of bloody material. The smears revealed high cellularity, papillary clusters, isolated low-to-tall columnar cells, mild to moderate atypia, hemorrhagic background, foam and hemosiderin-laden macrophages, calcification, rare mitoses, palisading row of cells and bipolar cytoplasmic eosinophilic granules. The smears were diagnosed as either suspicious or suggestive of papillary carcinoma. The histologic examination revealed invasive papillary carcinoma. CONCLUSION: Papillary carcinoma of the breast can be diagnosed by using a panel of cytologic findings that includes hypercellularity, papillary clusters, hemorrhagic background, palisading rows of tall columnar cells, cellular atypia and calcification. The interesting finding in this study was the presence of eosinophilic bipolar cytoplasmic granules, which has not been reported before.     

EMMPRIN (CD147) expression and differentiation of papillary thyroid carcinoma: implications for immunocytochemistry in FNA cytology

Y. Aratake, K. Marutsuka, K. Kiyoyama, T. Kuribayashi, T. Miyamoto, K. Yakushiji, S. Ohno, Y. Miyake, T. Sakaguchi, T. K. Kobayashi, A. Okayama, K. Tamura and E. Ohno
EMMPRIN (CD147) expression and differentiation of papillary thyroid carcinoma: implications for immunocytochemistry in FNA cytology Objective: Extracellular matrix metalloproteinase inducer (EMMPRIN) and its induced matrix metalloproteinases (MMPs) play a crucial role in tumour progression, invasion and metastasis. EMMPRIN expression has been demonstrated in several tumours, but its expression profile in thyroid cancer remains unclear. Methods: We evaluated the expression profile of EMMPRIN at various stages of differentiation of thyroid carcinoma, including 20 cases of well‐differentiated papillary carcinoma (WDPC), 15 cases of papillary carcinoma with a poorly differentiated carcinoma component (PC/PDC) and four cases with an undifferentiated carcinoma (UDC) component, using paraffin‐embedded sections for immunohistochemical stains. Also, we used 32 fine needle aspiration cytology and imprint smears from the same cases for immunocytochemical stains. The staining results were evaluated with a scoring system. Results: Immunohistochemical staining showed that EMMPRIN expression was absent or weak in almost all WDPC specimens, whereas it was moderate or strong in PDC and UDC components. In tumours that showed a gradual morphological transformation from WDPC to PDC components, the expression of EMMPRIN was progressively stronger from the areas of WDPC to those of PDC. WDPC, PC/PDC and UDC had expression scores of 4.9, 45.0 and 245.7, respectively. Results of immunocytochemical staining showed almost the same staining profile as those of immunohistochemical staining. The cytological atypia of EMMPRIN‐positive cells was greater than that of negative cells. Conclusion: These results indicated that EMMPRIN expression correlates significantly with the degree of dedifferentiation of thyroid carcinoma. This study demonstrates the feasibility of expression of EMMPRIN using fine needle aspiration samples. Therefore, immunocytochemical analysis of EMMPRIN may be a novel aid to evaluate the differentiation of thyroid carcinoma.     

Cytopathology of papillary carcinoma of the thyroid by fine needle aspiration

To delineate the cytologic presentation of papillary carcinoma of the thyroid, the fine needle aspiration smears were studied from 87 surgically proven cases. Six diagnostically useful findings were identified: papillary fronds, monolayered sheets, tissue fragments, intranuclear cytoplasmic inclusions, psammoma bodies and multinucleated giant cells. From 1,500 smears on "cold" nodules of the thyroid, 6 known false-negative and 4 false-positive diagnoses for papillary carcinoma were made. The estimated accuracy of the fine needle aspirate diagnosis of papillary carcinoma is 94%.     

Columnar cell carcinoma of the thyroid. Fine needle aspiration findings in a case

Columnar cell carcinoma is a recently described rare tumor of the thyroid. The fine needle aspiration cytologic findings of one example are reported. In the smears, the tumor fragments showed papillary and glandular patterns. The tumor cells were columnar and exhibited pseudostratification of the nuclei. The nuclei were oval to elongated and possessed stippled chromatin and inconspicuous nucleoli; occasional ones exhibited longitudinal grooving. It is important to distinguish this tumor from papillary carcinoma of thyroid because of its much more aggressive behavior, from metastatic adenocarcinoma for obvious treatment considerations, and from medullary carcinoma.     

Langerhans cell histiocytosis of the thyroid gland. A case report

BACKGROUND: The variant of Langerhans histiocytosis commonly encountered in adults is the benign, localized form (eosinophilic granuloma). The more-aggressive or diffuse type (Letterer-Siwe disease) is rare in adults. CASE: A 28-year-old woman presented with enlargement of the thyroid gland three years after she had been diagnosed with and placed on treatment for diabetes insipidus. Thyroidectomy was performed following an initial fine needle aspiration cytology report of either papillary thyroid carcinoma or Langerhans cell histiocytosis. The latter diagnosis was confirmed on histopathology and immunohistochemical staining for S-100 protein. Intracellular Birbeck granules were also demonstrated by electron microscopy. The disease progressed over a 10-week period to involve the kidneys, resulting in renal dysfunction. CONCLUSION: Synchronous or metachronous involvement of the hypothalamus and thyroid gland by Langerhans histiocytosis could not be excluded in the present case, with subsequent progression to involve other organs. This was an unusual presentation of the disease in an adult.     

Adenoid cystic pattern in follicular variant of papillary thyroid carcinoma: a report of four cases

S. Mandal, and S. Jain
Adenoid cystic pattern in follicular variant of papillary thyroid carcinoma: a report of four cases Objective: An adenoid cystic pattern in thyroid tumours is a rare finding that may be seen in papillary carcinoma of thyroid (PCT), the follicular variant of PCT (FV‐PCT), a rare cribriform‐morular variant of papillary carcinoma of thyroid (CMV‐PCT) and follicular carcinoma. There is little published cytological literature describing these patterns. We report four cases of PCT with this unusual pattern. Methods: Fine needle aspiration (FNA) cytology was performed on four patients with a neck lump using a 22‐G needle; smears were stained with Giemsa and Papanicolaou stains. Immunocytochemical staining for thyroglobulin was done in all cases. Results: The patients were female and ranged in age from 18 to 46 years. They presented with a gradually increasing mass in the neck. FNA smears in all cases showed nuclear features of PCT. There were also prominent follicular areas with hyaline globules in some of the cell clusters reminiscent of adenoid cystic carcinoma and, in places, morula‐like groups of neoplastic cells were also seen. Immunocytochemistry for thyroglobulin was positive in all cases but negative in the hyaline globules. Conclusions: Adenoid cystic areas with morula‐like groups in PCT are a rare finding. Cytopathologists and clinicians should be aware of these distinct features in thyroid tumours to avoid diagnosing metastatic adenoid cystic carcinoma. It is also important to rule out CMV‐PCT since that variant is mostly associated with familial adenomatous polyposis, although sporadic occurrence is known.     

Fine needle aspiration of follicular variant of papillary thyroid carcinoma presenting with pleural effusion: a case report

BACKGROUND: Malignant pleural effusion in association with mesothelioma, bronchogenic carcinoma and breast carcinoma is common, although less frequently reported with other malignancies. We report a follicular variant of papillary thyroid carcinoma (FVPTC), diagnosed on fine needle aspiration cytology (FNAC) of thyroid and lymph nodes and subsequently proved to have metastasized to the pleural cavity. CASE: A 46-year-old man presented with history of breathlessness, thyroid swelling, pleural effusion and bilateral cervical lymphadenopathy. FNAC of the thyroid swelling and the lymph nodes showed features of FVPTC with cervical lymph node metastasis. Pleural fluid examination led to suspicion of pleural involvement by metastatic deposit, confirmed by subsequent pleural biopsy. CONCLUSION: Thyroid malignancies presenting with pleural effusion are rare. In this case, although pleural fluid cytology suggested involvement of pleura, a definitive diagnosis could be rendered only on pleural biopsy. An ancillary aid, such as immunocytochemistry, could have helped establish pleural involvement on routine pleural fluid cytology alone. This case emphasizes the possible existence of rare cases of FVPTC that may be associated with a dismal prognosis. In our case, initial diagnosis of FVPTC could be made only on correlating FNA features of thyroid aspirate with those of lymph node aspirate.     

Fine needle aspiration cytology of the thyroid: a comparison of 5469 cytological and final histological diagnoses

OBJECTIVE: We evaluated the efficacy of fine needle aspiration cytology (FNAC) of the thyroid in a series of 5469 lesions with histological control and studied the causes of, and the possibility of reducing the limitations of the method. METHODS: FNAC was always performed by a pathologist under the guidance of a clinician, using a 22-gauge needle. Generally two aspirations were carried out, and usually four slides were obtained for each nodule; they were then stained with May-Grünwald-Giemsa and with Papanicolaou. The cytological diagnoses were classified in four groups: inadequate, benign, suspicious and malignant. RESULTS: We obtained a complete sensitivity of 93.4%, a positive predictive value of malignancy of 98.6%, and a specificity of 74.9%. At histological control, the cytological diagnosis of Hurthle cell neoplasm corresponded to a significantly higher incidence of malignant neoplasms than the diagnosis of non-Hurthle cell follicular neoplasm (32.1% versus 15.5%). There were 66 false-negative findings, the main cause of diagnostic error (24 cases) being failure to recognize the follicular variant of papillary carcinoma. The number of inadequate FNACs was low (4.2%). CONCLUSION: Our study confirmed the great efficacy of thyroid FNAC. A cytological diagnosis of Hurthle cell neoplasm should be considered an indicator of high risk. Awareness that failure to recognize the follicular variant of papillary carcinoma was the main problem in the interpretation of thyroid FNAC should lead to a decrease of false-negative diagnoses. The inadequate rate was very low, as it was the pathologist personally who performed the needle aspiration.     

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.     

Fine needle aspiration cytologic findings of micropapillary carcinoma in the lung: a case report

BACKGROUND: Micropapillary carcinoma is a variant of adenocarcinoma described in many anatomic sites and most recently in the lung. The cytologic recognition of this distinct pathologic entity in transthoracic needle aspiration specimens is important in providing prognostic information and therapeutic guidance. CASE: A 58-year-old woman presented with a < 1-cm lesion in the left breast identified on screening mammogram. A core biopsy of this lesion revealed an estrogen and progesterone receptor positive tubular carcinoma. Before a hookwire localization biopsy, a chest x-ray revealed a 1.7-cm spiculated mass in the right lower lobe. The diagnosis of adenocarcinoma with micropapillary features was made by fine needle aspiration cytology (FNAC). The lobectomy specimen showed a combination of adenocarcinoma, papillary adenocarcinoma and micropapillary carcinoma. CONCLUSION: Micropapillary carcinoma is a unique variant of adenocarcinoma, having important clinical associations because of its propensity for angiolymphatic invasion and higher stage at disease presentation. This case demonstrates the cytomorphologic characteristics of micropapillary carcinoma in a transthoracic FNA of the lung.     

Histologic analysis and comparison of techniques in fine needle aspiration-induced alterations in thyroid

OBJECTIVE: To assess histologic alterations following fine needle aspiration (FNA) of the thyroid and differentiate these from ominous lesions, such as papillary carcinoma thyroid, as well as assess and compare the degree of tissue trauma from the techniques: needle only vs. needle with syringe, size of needle and number of aspirations. STUDY DESIGN: Thyroidectomy specimens of 100 cases with prior FNA biopsy were selected. The changes called "worrisome histologic alteration following fine needle aspiration of the thyroid" (WHAFFT) were studied. Number of FNAs, needle size and technique were tabulated for 73 of 100 cases. RESULTS: Worrisome changes were confined to areas near the needle tract and hence could be differentiated from ominous lesions. Control cases did not show WHAFFT lesions. Non-aspiration FNA cytology (FNAC) technique results in fewer, less frequent WHAFFT changes. The increasing number of FNAs leads to statistically significant increase in infarction, necrosis and vascular changes. A gradation in the WHAFFT changes, directly proportional to the increasing diameter of the needle, was observed. CONCLUSION: The pathologist should be aware of WHAFFT to avoid misinterpretation. The technique of non-aspiration FNAC is significantly less traumatic. An increase in FNAs or size of needle results in more severe WHAFFT changes.     

The potential value of the demonstration of thyroglobulin by immunoperoxidase techniques in fine needle aspiration cytology

The peroxidase-antiperoxidase method for the demonstration of thyroglobulin was performed on 30 fine needle aspiration smears. All of the benign thyroid lesions plus the papillary and follicular carcinomas of the thyroid were positive for thyroglobulin. Two cases of metastatic thyroid carcinoma in lymph nodes were also positive. Medullary carcinoma of the thyroid and ten control smears from various other tissues were negative. This proves the sensitivity and the specificity of the method, which may be used in routine cytology and may add to the accuracy of diagnosing metastatic tumors suspected of being of thyroid origin. The intranuclear cytoplasmic vacuoles in papillary carcinoma of the thyroid were negative for thyroglobulin. This unexpected finding is demonstrated, and a possible explanation is offered.     

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.