Infarction in a thyroid nodule after fine needle aspiration: report of 2 cases with a discussion of the cause of pitfalls in the histopathologic diagnosis of papillary thyroid carcinoma.

BACKGROUND: In case of difficulty in the interpretation of fine needle aspiration (FNA) smears of a thyroid nodule, histopathologic examination is advised to arrive at a definitive diagnosis. On rare occasions, a specific diagnosis may be given based on cytologic examination, but FNA is followed by infarction of the thyroid nodule, with resultant difficulty in interpretation or even misinterpretation of bistopathologic material. We report 2 such cases. CASES: Two cases were diagnosed as papillary thyroid carcinoma (PTC) by FNA cytology, but histopathology reports indicated colloid goiters with infarcted nodules. Review of histopathologic material showed features of PTC in the viable tissue at the periphery of nodules. Immunohistochemical study for galectin-3 and CD44 in 1 of the cases supported the diagnosis of PTC. CONCLUSION: We suggest that while reporting on an infarcted nodule in paraffin sections of a thyroidectomy specimen, the histopathologist should be careful to look thoroughly at its periphery for the surviving cells and their detailed morphologic features, especially if there is a prior FNA cytology report of a neoplasm.

Hodgkin's lymphoma: diagnostic difficulties in fine-needle aspiration cytology.

It is commonly believed that cytodiagnosis of Hodgkin's lymphoma (HL) is much easier than that of non-Hodgkin lymphoma (NHL). However, recognition of certain NHL subtypes with Reed-Sternberg (R-S)-like cells and results of immunohistochemical studies point to the contrary. To study the limitations of cytology in diagnosis of HL, fine-needle aspiration (FNA) smears of 130 lymphoma or suspected lymphoma cases were reviewed. Initial and reviewed cytodiagnoses were compared with histopathology in 89 cases. Immunocytochemical and immunohistochemical studies were performed in 56 and 59 cases, respectively. Among histologically diagnosed HL cases, definitive cytodiagnosis of HL (initial as well as reviewed) was significantly less frequent than cytodiagnosis of NHL among histologically diagnosed NHL cases (P = 0.0328 and = 0.0001, respectively). On the other hand, cytologically diagnosed HL/NHL cases were significantly more frequent in the former group (P = 0.0001 and = 0.0018, respectively). ALCL and TCRBCL were the two NHL subtypes which created confusion with HL in FNA smears. Twenty-one cytohistological concordant HL cases and equal number of discordant cases were compared. When compared with discordant group, the patients in concordant group were significantly younger (P = 0.045). Hodgkin/Hodgkin-like cells and typical R-S cells were significantly more frequent in FNA smears of the concordant group (P = 0.0478 and = 0.0431, respectively). Immunocytochemical and immunohistochemical studies showed good correlation with histological diagnosis of HL. It is suggested that proper interpretation of cytologic features, together with use of immunocytochemical parameters can help in reducing the margin of error in cytodiagnosis of HL.

Papillary thyroid carcinoma: evidence for intracytoplasmic formation of precursor substance for calcification and its release from well-preserved neoplastic cells.

Psammoma bodies (PBs) are believed to represent a process of dystrophic calcification over nonviable and dying tissues. Light microscopic and ultrastructural observations suggest that PB formation follows the intracellular assembly of precursor substances and their calcification leading to death of tumor cells and their release. It may also be the result of local secretion of precursor substances like collagen by tumor cells into extracellular space and their calcification. In an earlier reported study, we demonstrated the extracellular localization of various precursor forms of PBs and of irregular calcification in fine-needle aspiration (FNA) smears of papillary thyroid carcinoma (PTC). In this report, we describe a PTC case with intracellular formation precursor substances for calcification and their release from the well-preserved neoplastic cells before undergoing calcification. Ultrasound-guided FNA smears from a small nodule in the left lobe of thyroid in a 40-year-old woman revealed a PTC with numerous intracytoplasmic targetoid bodies, which were magenta colored in MGG stain. On their release from the neoplastic cells, these targetoid precursor bodies were found to be forming pools of matrix material, some of which showed evidence of calcification. The cytologic findings were confirmed by histopathology of the tumor in the thyroidectomy specimen. For the first time, we demonstrate through cytomorpholgy the intracytoplasmic formation of targetoid bodies as precursor substances for calcification and their release from well-preserved cells in PTC. We suggest that the calcification in PTC may not necessarily be taking place over nonviable and dying cells.

Secretory activity in medullary thyroid carcinoma: a cytomorphological and immunocytochemical study.

Medullary thyroid carcinoma (MTC) is a relatively rare thyroid malignancy of C-cell origin that secretes calcitonin. Although its varied cytomorphologic features are well described in literature, very little is mentioned about the morphologic manifestation of its secretory activity. This study, based on nine fine needle aspiration (FNA) samples from eight MTC patients, is an attempt to present the varied cytomorphologic features suggesting secretory activity in MTC as observed in Papanicolaou and MGG stained FNA smears and correlate them with the immunocytochemical (ICC) staining for calcitonin performed on FNA smears and the serum calcitonin values. The average number of cells in these nine samples was as follows: oval/triangular/plasmacytoid (56.7%), small round (23.6%), spindle-shaped (12.7%), and miscellaneous (7.1%). The cytomorphological features suggesting secretory activity, viz., fine cytoplasmic vacuoles, azurophillic granules, marginal vacuoles, and intracytoplasmic lumina (ICL) with secretions were present in eight, eight, five, and six samples, respectively. Material likely to be amyloid, based on morphological features, was present extracellularly in three samples and both intracellularly and extracellularly in six samples. Immunocytochemically, all the nine samples stained for calcitonin and all the three stained for chromogranin showed positive cytoplasmic reaction in the neoplstic cells. The background amyloid (in six samples), the coarse cytoplasmic granules (in two samples), and the contents of ICL (in one sample) were found to be positively stained for calcitonin. The intracytoplasmic secretory material appeared to be diffusing out of some cells both in the routine MGG stained smears and in the smears stained for calcitonin. Histopathology reports of seven samples in six patients confirmed the cytodiagnosis of MTC in all. Baseline serum calcitonin values in three cases and postoperative serum calcitonin levels during follow-up in three others were high. Thus, our study highlighted the morphological manifestations of secretory activity in MTC and the nature of secretory material as calcitonin, supported by immunocytochemical staining and serum calcitonin level.

Papillary thyroid carcinoma and its variants in fine needle aspiration smears. A cytomorphologic study with special reference to tall cell variant.

OBJECTIVE: To study the fine needle aspiration (FNA) cytologic features of papillary thyroid carcinoma (PTC) with special reference to its tall cell variant (TCV), which is the most aggressive of the variants. STUDY DESIGN: Fifty-four PTC cases were classified into variants, and the frequency of well-known morphologic criteria was determined. Four parameters were quantitatively analyzed based on a study of 200 consecutive neoplastic follicular cells: shape of cells, color of cytoplasm, intranuclear cytoplasmic inclusion (INCI) and nuclear grooves. RESULTS: The PTC cases included 6 TCV (> or = 30% tall cells), 8 cases with a significant tall cell component (sig. TCC) having 10-29% tall cells, 17 usual variant (UV), 17 follicular variant (FV) and 6 miscellaneous variants. TCV differed significantly from UV and FV in having a higher tall cell count, higher count of cells with reddish cytoplasm and INCI, and higher frequency of cases with lymphocytic infiltration. PTC (with significant tall cell component [TCC]) differed significantly from TCV with regard to tall cell count and lymphocytic infiltration, from UV with respect to tall cell count and monolayered sheets, and from FV with respect to tall cells, INCI, grooved nuclei, acinar formation, fire-flare appearance and giant cells. CONCLUSION: TCV was cytologically distinct from other variants. The biologic behavior of PTC cases with significant TCC, which morphologically seem to be a group intermediate between TCV on the one hand and UV and FV on the other, however, needs to be carefully monitored.

Role of fine needle aspiration cytology in the diagnosis of swellings in the salivary gland regions: a study of 712 cases.

INTRODUCTION: A mass in the salivary gland region often presents a diagnostic challenge with regard to its site of origin (salivary versus nonsalivary), benign or malignant nature, and tissue-specific diagnosis. The present study describes the utility of fine-needle aspiration (FNA) cytology in the diagnosis of these lesions. SUBJECTS AND METHODS: Over a 6-year period (January 1994 to December 1999), 712 patients aged between 6 months and 91 years (median, 37 years) were subjected to FNA of swellings in their salivary gland regions. Male:female ratio was 1.28:1. The swellings were mostly located in the parotid (323 cases), submandibular (343 cases), and upper cervical region (27 cases). Swellings of oral (5 cases) and sublingual (2 cases) sites were rare. The lesions diagnosed by FNA cytology were compared among the major salivary glands. Cytologic diagnoses were correlated with histology in 45 cases. RESULTS: Benign nonneoplastic lesions were the most common (73%), followed by neoplasms (20%), and those with atypical cytology (1%). Cytologic material was inadequate in 6% cases. Parotid gland region was involved more frequently by neoplasms (27.1%) than the submandibular gland region (13.7%, p < 0.0001). Inflammatory processes affected the submandibular gland region more commonly (42.0%) than the parotid (32.6%, p = 0.0164). Pleomorphic adenoma was the most common neoplasm (61.5%), followed by Warthin's tumor (12.6%). Malignancies accounted for 10.5% of neoplasms. Frequency of involvement of parotid by Warthin's tumor (16.7%) was significantly higher than that of submandibular gland (2.3%, p = 0.0191). However, the submandibular gland was more commonly affected by malignancy than the parotid gland (p = 0.0003). Sensitivity, specificity, and diagnostic accuracy of FNA cytology for all neoplastic lesions of the salivary gland were 94.6, 75.0, and 91.1%, respectively. The corresponding figures for malignancies were 60.0, 95.0, and 91.1%, respectively. CONCLUSION: FNA cytology is very useful for the diagnosis of salivary gland lesions. However, sampling and interpretation errors may occur. The low specificity for the diagnosis of neoplasms as a whole and the poor sensitivity for malignancies found in our study can be attributed to the relatively small number of benign nonneoplastic and malignancy cases with available histopathologic diagnoses.