Worrisome histologic alterations following fine-needle aspiration of benign parotid lesions

Infarction of basal cell adenoma of the parotid gland: First case report and literature review on CTNNB1 I35T mutations in salivary basal cell neoplasms

Infarction has rarely been reported in some types of salivary gland tumors. In this study, we present the first case of infarction occurring in salivary basal cell adenoma. A 62-year-old male presented with swelling in the left parotid region. Histopathological examination revealed extensive central necrosis surrounded by a rim of viable tumor tissue showing the typical histology of basal cell adenoma. Nuclear β-catenin expression and the CTNNB1 p.I35T (c.104 T > C) mutation were identified in the tumor. A diagnosis of basal cell adenoma with central necrosis was made, and the postoperative period was uneventful. In addition, we review the literature on CTNNB1 I35T mutations in basal cell neoplasms of the salivary glands. Awareness of the possible occurrence of infarction and the high frequency of the unique mutation in basal cell adenoma may help in the differential diagnosis of salivary gland tumors.

The Milan System for Reporting Salivary Gland Cytopathology

OBJECTIVES

Our study assesses whether the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) offers any benefit over the original cytology classification, and measures interobserver agreement.

METHODS

Four cytopathologists retrospectively blindly classified preoperative cytology by MSRSGC from 101 resected salivary tumors. Consensus MSRSGC diagnoses were correlated with surgical pathology diagnoses and compared with the original cytology classification. Diagnostic parameters were calculated for both systems. Interobserver variability was assessed.

RESULTS

The original cytology classification vs MSRSGC had sensitivity, specificity, positive predictive value, and negative predictive value of 75.0% vs 78.3%, 97.1% vs 98.0%, 91.2% vs 94.7%, and 90.1% vs 90.0%, respectively. The original cytology classification risk of neoplasm (RON) was 91.7% for "negative for malignancy" and 100.0% for other categories. The MSRSGC RON was 71.4% in category II (nonneoplastic) and 100.0% in all other categories. The original cytology classification risk of malignancy (ROM) ranged from 0.0% for "atypical" to 100.0% for "positive for malignancy." The MSRSGC ROM ranged from 0.0% in categories I (nondiagnostic) and III (nonneoplastic) to 100.0% in category VI (malignant). Weighted agreement using the MSRSGC was 92% (Gwet AC1, 0.84); unweighted agreement was 69% (Gwet AC1, 0.64). MSRSGC category IVA (benign neoplasm) was most likely to show interobserver agreement, with complete agreement in 67% of cases.

CONCLUSIONS

The MSRSGC performs similarly to the original cytology classification and shows relatively high interobserver agreement.

Chronic Granulomatous Dacryoadenitis Associated With Pleomorphic Adenoma

Chronic granulomatous inflammation occurs rarely alongside pleomorphic adenomas of the major salivary glands but would not appear to have been reported with lacrimal gland adenomas. We describe the clinical features, imaging and histopathology for 4 patients (3 female) who had granulomatous inflammation alongside lacrimal gland adenomas-the patients being with age 39, 44, 48, and 53 years at time of surgery. One patient had an asymptomatic lesion found on imaging, and the other 3 had symptoms for between 3 years and several decades. Conjecturally, this rare phenomenon might arise from an inflammatory response to leakage of secretions from the ductular components of the glands.

Pleomorphic adenoma: the great mimicker of malignancy

Pleomorphic adenoma (PA) is the most common salivary gland neoplasm, and its diagnosis is straightforward in the majority of cases. However, not infrequently, PA shows unusual and uncommon histological features that can be confused with those of malignancy. The difficulties in diagnosing PA arise from its ability to mimic invasion, show atypical or metaplastic cytomorphology, and show morphological features that overlap with those of established salivary gland carcinomas. In addition, recognising early malignant transformation to carcinoma ex-pleomorphic adenoma continues to be a frequent challenge. This review describes the diagnostic pitfalls of PA, and offers a systematic approach to avoid them by combining classic histopathology with novel immunohistochemical and molecular tests.

Spontaneous infarction of pleomorphic adenoma of the parotid gland: A case report

Infarction after the fine-needle aspiration (FNA) procedure is a well-recognized phenomenon of salivary gland lesions. Though extremely rare, spontaneous infarction without previous FNA can occur in pleomorphic adenoma (PA). The present report describes a fourth cytological case of spontaneous infarction of PA of the parotid gland using immunocytochemical analysis, to the best of our knowledge, for the first time. A 57-year-old Japanese female presented with persistent swelling of the right neck region. Physical examination revealed a tumour in the right parotid gland, and FNA examination of the tumour was performed following surgical resection. The Papanicolaou smear demonstrated the presence of fully necrotic cell clusters of varying sizes in a necrotic background. Only a few viable cell clusters were observed. These cells were polygonal to spindle-shaped, and exhibited large round to oval nuclei with a conspicuous nucleoli. Although nuclear pleomorphism was noted, the nuclear chromatin was fine. No neoplastic myoepithelial cells were observed. Therefore, it was suspected that these cells were malignant. Immunocytochemical analysis indicated that these atypical cells were positive for p40. Histopathological examination of the resected parotid gland tumour revealed infarcted PA. Our study revealed that the presence of atypical squamous metaplastic cells in a necrotic background was a characteristic cytological feature of infarcted PA, and that these atypical squamous cells can have large nuclei with conspicuous nucleoli and exhibit pleomorphism. Although cytological diagnosis of infarcted PA is difficult, pathologists and cytopathologists must consider the presence of atypical metaplastic squamous cells in benign salivary gland tumours, including infarcted PA.

Xanthogranulomatous change in a pleomorphic adenoma: An extremely rare variant/degenerative change. Is it fine needle aspiration induced?

Pleomorphic adenoma (PA) is the most common benign salivary gland tumor characterized by morphological diversity, metaplastic changes, degeneration, cystic change, altered differentiation, and rarely malignant transformation, thereby may create a diagnostic dilemma on cytology. Xanthogranulomatous (XG) inflammation within a PA could be due to XG sialadenitis coexistent with PA or preoperative fine-needle aspiration cytology (FNAC) induced histologic alteration. The argument in favor of this hypothesis is that the changes seen in the histopathology would not be present in the cytology, implying that the alterations were most likely due to the traumatic injury of needling rather than spontaneous change of the lesions themselves. These FNAC induced changes are focal in most of the cases, so the underlying lesion is readily identifiable, but on rare occasions they are so extensive that it can masquerade as a malignancy. We report a case of XG change in a PA in a 39-year-old male of 8 years standing. Through this case we wish to emphasize that knowledge of a previous FNAC and its potential effects on histology of the subsequent surgical specimen is necessary to avoid potential misdiagnosis.

Discordance between fine-needle aspiration cytology and histopathology in patients with mucoepidermoid carcinoma of parotid gland

INTRODUCTION

Fine-needle aspiration cytology (FNAC) is an important diagnostic tool used preoperatively for the diagnosis of parotid lump. Mucoepidermoid carcinoma comprises 5-10% of all salivary gland tumours. It poses a diagnostic challenge on FNAC with high false negative rate. The objective of this study was to evaluate the discordance between cytology/FNAC and histopathology in patients with mucoepidermoid carcinoma.

MATERIAL AND METHODS

A cross-sectional study was conducted from 1 January 2010 to 31 December 2014. Patients aged 18 years and above with FNAC or histopathology suggestive of mucoepidermoid carcinoma were identified. FNAC when compared with histology (gold standard) was classified into true positive (presence of mucoepidermoid carcinoma correctly diagnosed on FNAC), true negative (absence of mucoepidermoid carcinoma correctly diagnosed on FNAC), false positive (FNAC incorrectly diagnosed mucoepidermoid carcinoma), false negative (FNAC failed to diagnose mucoepidermoid carcinoma).

RESULTS

A total of 16 patients fulfilled our eligibility criteria. Seven cytological samples were true positive (ie correctly diagnosed mucoepidermoid carcinoma by FNAC), eight cytological specimens were false negative (ie could not pick up mucoepidermoid carcinoma on FNAC). One case was false positive on cytology (ie diagnosed mucoepidermoid carcinoma on FNAC but was reported to be Warthin's tumour on histopathology) and none were true negative.

CONCLUSION

FNAC is not reliable for diagnosis of mucoepidermoid carcinoma. More than 50% of our patients had discordant results between cytology and histology. We recommend a high index of suspicion for mucoepidermoid carcinoma given the poor yield of cytology.

Spontaneously infarcted parotid tumours: MRI findings

OBJECTIVES

To report MRI findings of spontaneous infarction in parotid tumours.

METHODS

14 patients (13 male, 1 female; mean age 73 years) with spontaneously infarcted parotid tumours were reviewed retrospectively. MR images were assessed for the location, the presence of synchronous parotid masses, margin characteristics, signal intensity on T ₁ and T ₂ weighted images, and internal architecture according to the distribution of T ₂ signal hyperintensity.

RESULTS

12 tumours were located in the parotid tail and 2 in the superficial lobe. Synchronous parotid masses were seen in four tumours, three of which were located in the ipsilateral parotid tail and one in the contralateral parotid tail. Seven tumours had well-defined margins and seven had ill-defined margins. The signal intensities on T ₁ weighted images were a mixture of high and intermediate in all cases; in 11 tumours, hyperintense areas were dominant. On T ₂ weighted images, all tumours also showed a mixture of high and intermediate signal intensities. Internal architectures on T ₂ weighted images were mosaic hyperintensity in three tumours, central hyperintensity in five, and multiseparated hyperintensity in six.

CONCLUSIONS

Spontaneously infarcted parotid tumours were mostly located in the parotid tail and showed mixed signal intensities with predominant hyperintensity on T ₁ weighted images. Half of the tumours had ill-defined margins, and the internal architectures varied.

Cytological features of the Warthin-like variant of salivary mucoepidermoid carcinoma

Warthin-like mucoepidermoid carcinoma is a recently proposed variant of musoepidermoid carcinoma. Histologically, it is characterized by its close resemblance to Warthin tumor, including dense lymphocytic infiltration, flattened intermediate epithelium resembling squamous metaplasia, and cystic change. Given its histologic similarity to Warthin tumor, confirmatory testing for MAML2 rearrangement is often required for this diagnosis. Here we present the first cytologic reports of two 53-year-old female patients with parotid masses. In both cases, the fine needle aspirations showed fragments of bland epithelium with a squamous appearance, mucinous cyst content, and focal lymphocytic background. Neither frank keratinization nor mucinous cells were identified in the smears. Fluorescence in situ hybridization (FISH) study confirmed MAML2 rearrangement on the resection specimens in both. Other cytologic differential diagnoses, including Warthin tumor with metaplasia, lymphadenoma, and lymphoepithelial cyst, were briefly discussed.

Low Grade Carcinoma Ex-Pleomorphic Adenoma: Diagnosis and Diagnostic Challenges Caused by Fine Needle Aspiration: Report of Three Cases and Review of Literature

Low grade carcinoma ex pleomorphic adenoma (LG CXPA) is a rare low grade malignant neoplasm arising from preexisting pleomorphic adenoma (PA). LG CXPA demonstrates no overt cytological atypia, and can be difficult to distinguish from cellular PA. Invasive growth is one of the hallmarks of LG CXPA, e.g., tumor extends beyond the capsule and into adjacent non-neoplastic tissue. However, it is known that capsular and vascular invasion, as well as the presence of stroma-rich PA in soft tissue without a capsule (pseudopodia) can be seen in PA. These histological findings have no prognostic significance and are not diagnostic of malignancy. In addition, recurrent PA typically presents as numerous nodules extending into soft tissue and skeletal muscle, which again are not considered malignant features. Thus, "infiltrative growth" of LG CXPA is difficult to define and diagnosis is challenging to many practicing pathologists. In this study, we report three cases of LG CXPA. We review the diagnostic criteria for LG CXPA, and discuss the diagnostic challenges caused by fine needle aspiration (FNA) changes. FNA is widely used as a cost-effective, quick and accurate method for diagnosing salivary gland lesions. Histological changes post-FNA are usually focal and mild, and are not causes of diagnostic difficulties. According to our knowledge, this is the first report of LG CXPA complicated with FNA changes.

The oncofetal protein IMP3 is an indicator of early recurrence and poor outcome in mucoepidermoid carcinoma of salivary glands

OBJECTIVE

Mucoepidermoid carcinoma (MEC) is the most common primary malignancy of the salivary glands. Insulin-like growth factor-II mRNA-binding protein-3 (IMP3) is an important prognostic factor in some cancers and a tool that differentiates between benign and malignant pancreatic lesions. This study aimed to identify a relationship between the expression of IMP3 and the outcome of salivary gland MEC, as well as to differentiate MEC from pleomorphic adenoma (PA).

METHODS

Tissue specimens from 70 cases of salivary gland MEC, 40 cases of PA, and 10 cases with normal salivary gland were examined immunohistochemically for IMP3. The association among the expression of IMP3, clinicopathological characteristics and patient's survival was assessed.

RESULTS

IMP3 was present in 51.4% of MEC but absent in PA and normal salivary gland tissues. IMP3 expression was associated with age > 60 years, submandibular gland tumors, tumor size > 4 cm, high-grade tumors, lymph node metastasis, involvement of surgical margins, perineural invasion, distant metastasis, advanced TNM stage, tumor relapse, and death ( P<0.05). Increased expression of IMP3, tumors of the submandibular gland, and lymph node metastasis were independent prognostic factors of -free survival (DFS). In addition, IMP3 was a strong predictor of overall survival (OS) together with distant metastasis and intermediate and high-grade tumors.

CONCLUSIONS

IMP3 expression is highly important in evaluating the outcome of MEC. IMP3 can be used to differentiate MEC from PA of salivary glands.

Diagnostic challenges in cytology of mucoepidermoid carcinoma: Report of 6 cases with histopathological correlation

BACKGROUND

Mucoepidermoid carcinoma (MEC) is a malignant salivary gland neoplasm with extreme morphologic heterogeneity and hence rendering a definitive fine needle aspiration cytology (FNAC) diagnosis of this neoplasm is really challenging. The present study was undertaken to elucidate the cytological features of MEC and explore the diagnostic accuracy and pitfalls by comparing with subsequent histopathology.

MATERIALS AND METHODS

The present study was conducted over a period of 2 years wherein we obtained six histopathologically confirmed cases of MEC. These patients were initially subjected to FNAC. The cytologic features studied included presence of mucous cells, intermediate cells, and squamous cells. Presence of background mucinous material was also noted. The cytological features were compared with the subsequent histopathology.

RESULTS

Of the 6 cases of MEC, a definite cytological diagnosis was possible only in 2 cases. Of the remaining 4 cases, 2 cases were broadly diagnosed in cytology as neoplasm with cystic degeneration and 2 cases were underdiagnosed as pleomorphic adenoma.

CONCLUSIONS

A satisfactory aspirate with all three types of cells; mucous, intermediate and squamous cells may not be obtained in all cases of MEC for providing a definite diagnosis. Hence, a good clinicoradiological correlation, a high index of suspicion and repeated aspirations especially in cystic lesions may be particularly helpful in difficult cases. In addition, while dealing with mucinous cystic lesions with low cellularity, the importance of early excision should be communicated to the clinician since the possibility of low-grade MEC cannot be excluded.

Clinical utility of fine needle aspiration cytology in pediatric parotid tumors

OBJECTIVE

The purpose of this study was to evaluate the usefulness and accuracy of fine needle aspiration cytology (FNAC) in the diagnosis of pediatric parotid tumors.

METHODS

From June 2002 to June 2012, 22 patients ≤18-years-of-age with parotid mass were treated at Chonnam National University Hospital. Included in the study were 21 cases with preoperative FNAC. A retrospective chart review analyzed the results of FNAC and compared them with the corresponding histopathological diagnosis.

RESULTS

Twenty-one of the 22 patients had undergone preoperative FNAC, which diagnosed pleomorphic adenoma in 13 patients. The remaining eight patients were diagnosed with benign tumor (n = 6), malignant tumor (n = 1) or Kimura disease (n = 1). All 21 patients underwent parotid tumor removal. FNAC had a diagnostic sensitivity of 92.3%, positive-predictive value of 92.3% and accuracy of 90.5% for diagnosing pleomorphic adenoma of pediatric parotid tumor. FNAC had a diagnostic sensitivity of 100%, a positive-predictive value of 85% and accuracy of 85.7% for diagnosing benign parotid tumor.

CONCLUSIONS

Preoperative FNAC is a useful and accurate adjunct for preoperative evaluation of pediatric parotid tumors. We recommend that preoperative FNAC should be part of the initial evaluation of pediatric patients with parotid masses.

A perspective of comparative salivary and breast pathology. Part I: microstructural aspects, adaptations and cellular events

This is the first part of a review comparing the pathology of salivary and mammary glands. Here, less obvious similarities and differences in functional histology and their influences on pathology are examined with emphasis on myoepithelial cells, stromal components, analogues of mucosa-associated lymphoid tissue, steroid receptors, and intraparenchymal cells of monocytic lineage. Particular cell phenotypes (oncocytic, apocrine, neuroendocrine and clear) are critically evaluated and responses to atrophy, infarction and fine-needle aspiration biopsy procedures are highlighted together with aspects of metaplasia, regeneration, ageing and microcalcification. Areas of controversy or uncertainty which may benefit from further investigations are also discussed.

Rare Malignant and Benign Salivary Gland Epithelial Tumors

Although at least 24 distinct histologic salivary gland carcinomas exist, many of them are rare, comprising only 1% to 2% of all salivary gland tumors. These include epithelial-myoepithelial carcinoma, (hyalinizing) clear cell carcinoma, basal cell adenocarcinoma, cystadenocarcinoma, low-grade salivary duct carcinoma (low-grade cribriform cystadenocarcinoma), oncocytic carcinoma, and adenocarcinoma not otherwise specified. Few tumors (clear cell carcinoma and basal cell adenocarcinoma) have unique molecular correlates. Benign tumors, although histologically less diverse, are far more common, with pleomorphic adenoma and Warthin tumor the most common salivary gland tumors. Many benign tumors have malignant counterparts for which histologic distinction can pose diagnostic challenge.

Schwannoma-like pleomorphic adenoma of the parotid

Pleomorphic adenoma is the most common benign salivary gland tumour. It can occur in any salivary gland, but is most frequently found in the parotid gland. Chondroid metaplasia is a frequent finding in pleomorphic adenoma. Other forms of metaplasia have been described, but are encountered less frequently. We report a rare case of unusual pleomorphic adenoma of the parotid gland with schwannoma-like feature.

Diagnostic accuracy of fine-needle aspiration cytology in Warthin tumors

BACKGROUND

Our aim was to evaluate the diagnostic accuracy of fine-needle aspiration cytology (FNAC) for Warthin tumors of the parotid gland.

METHODS

All cytologic diagnoses of Warthin tumor between 1990 and 2007 were correlated with available histology. In addition, our results were compared to current literature.

RESULTS

In 310 cases, Warthin tumor was diagnosed by FNAC. In 133 cases, (43%) both cytology and histology were available. In 127 of these 133 cases (95.5%), the diagnosis Warthin tumor was confirmed by histology. In 4 cases (3%), a benign lesion was diagnosed and 2 (1.5%) revealed a malignant lesion. On review, those cytologic diagnoses were not certain. In the literature, 11 missed malignancies (5.4%) in 202 cases were reported.

CONCLUSION

The diagnostic accuracy of FNAC for the diagnosis of Warthin tumor is high and the percentage of missed malignant tumors is very low. Our results imply that a cytologic diagnosis of Warthin tumor may justify conservative treatment.

A cytohistologic correlation of mucoepidermoid carcinoma: emphasizing the rare oncocytic variant

It is well-known that the morphological variability of mucoepidermoid carcinoma (MEC) of the salivary glands may lead to interpretative difficulties on fine-needle aspiration (FNA) diagnosis. In this study we identify morphologic features that may be useful in the FNA diagnosis of MEC. The cohort included 23 cases of MEC; cytology and histology slides were reviewed and assessed for % cystic component, extracellular mucin, mucous and intermediate cells, oncocytes, cells with foamy/clear cytoplasm, keratinized cells and lymphocytes. On FNA 12/23 (52%) cases were diagnosed as consistent with or suggestive of MEC; 6/23 (26%) as salivary gland neoplasm and 5/23 (22%) as no tumor seen. The cystic component was ≥50% in 18/23 (78%) and <50% in 5 cases. The features prevalent in FNA and histology were: mucous cells (96% and 91%), extracellular mucin (91% both), intermediate cells (100 and 83%), lymphocytes (96 and 78%) and cells with foamy/clear cytoplasm (74% both). Oncocytes were seen in 43 and 22% and keratinized cells in 48 and 13% cases. Cases with oncocytes and lymphocytes were interpreted as favor Warthin's tumor on FNA. Presence of mucous cells, cells with foamy/clear cytoplasm, intermediate cells and lymphocytes in a mucinous background are diagnostic indicators of MEC; presence of oncocytes should not refrain from diagnosing MEC in FNA specimens.

Worrisome histologic alterations following fine-needle aspiration of the parathyroid

Fine-needle aspiration (FNA) is a procedure that is increasingly being performed. Artefacts occurring after FNA are reported to complicate the histological analysis of the tissue, mainly in the thyroid; WHAFFT (worrisome histologic alterations following FNA of thyroid) is well documented in the literature. The case of a male patient with hypercalcaemia who was subsequently found to have a nodule in the thyroid gland is reported here. He underwent FNA, followed by a total thyroidectomy and parathyroidectomy. The abnormality in the parathyroid gland showed worrisome histological changes that were suspicious of a malignant lesion, resembling the changes seen in the thyroid gland after FNA. Parathyroid cells were identified by a review of the previous FNA. The concept of WHAFFT, which can mimic the features of malignancy in the parathyroid gland, is therefore introduced.

The role of fine needle aspiration in the evaluation of parotid masses

PURPOSE OF REVIEW

Fine needle aspiration is a safe diagnostic technique that is widely employed for lesions of the head and neck. Among head and neck sites, the parotid gland stands apart for the number, diversity and peculiarity of pathologic processes to target this structure. This matchless complexity has prompted a thoughtful discussion regarding the application of the fine needle aspiration to parotid masses--a discussion that has primarily focused on the reliability of the fine needle aspiration as a diagnostic tool, and on its utility in guiding patient management.

RECENT FINDINGS

Recent studies have confirmed a high overall accuracy rate for fine needle aspiration evaluation of parotid masses, ranging from 90 to 95%. At the same time, these soaring accuracy rates cannot be uniformly anticipated across all diagnostic scenarios. Fine needle aspiration is notoriously unreliable in recognizing the malignant nature of the parotid carcinoma, providing its precise classification, and establishing its grade. A few malignant neoplasms are particularly prone to diagnostic error. Acinic cell carcinoma is frequently interpreted as benign or even nonneoplastic; and low-grade lymphomas are often discounted as inflammatory processes.

SUMMARY

Parotid gland masses are not particularly conducive to diagnostic accuracy and precision by fine needle aspiration. Accordingly, indiscriminant reliance on the fine needle aspiration findings at the expense of the clinical, radiographic, and intraoperative findings is unwarranted. Whether one uses the fine needle aspiration routinely or selectively in patients with parotid masses, the fine needle aspiration findings should contribute to, not displace, the overall diagnostic impression.

Preoperative cytology in the management of parotid neoplasms

BACKGROUND

This study evaluates the diagnostic role of preoperative cytology of parotid neoplasms. The method is particularly useful in the evaluation of the parotid diseases in which the same clinical features may be treated variously. Fine-needle aspiration biopsy is a simple and well-tolerated diagnostic tool, which provides accurate information for diagnosis and follow-up of the disease. The accuracy of the method partly depends on the operator skill.

MATERIALS AND METHODS

From a series of 452 subjects who underwent parotidectomy, preoperative cytological evaluation was available in 310 and compared with histological diagnosis in a retrospective review.

RESULTS

The agreement between histotype determination using fine-needle aspiration biopsy and final histological diagnosis was 79%, specificity was 100%, sensitivity was 83%, and diagnostic accuracy was 97%.

CONCLUSION

These findings demonstrated that, given the low complication rate, preoperative cytology is particularly useful in diagnosing parotid disease and in planning the surgical strategy and approach.

Kann die präoperative Feinnadelpunktion bei Parotistumoren die definitive histologische Diagnose erschweren?

INTRODUCTION

Fine-needle aspiration cytology (FNAC) is a minimally invasive procedure that offers high specifity and acceptable sensitivity in the preoperative diagnosis of parotid tumors. FNAC provides information that can be particularly valuable in surgical planning and patient education. In some cases, it may even help prevent unnecessary surgery. After an FNA procedure, on rare occasions, morphological changes in the tumor may be observed and can make a definitive histological examination difficult or even impossible.

METHODS

Histopathological changes in parotid tumors after preoperative FNAC are described on the basis of a case report and a survey of the literature.

RESULTS

In rare cases, puncture-induced histopathological changes, such as hyalinization of the subepithelial stroma, necrosis and squamous metaplasia, so extensive that a definitive histological diagnosis is difficult, are observed. In the present case report, fine-needle aspiration of a 3 x 2 cm tumor, which had been classified as malignant on the basis of cytological findings, resulted in complete necrosis and made a definitive histological diagnosis impossible. Similar cases have been described by other authors in recent years.

DISCUSSION

In rare cases, histological changes in the tumor tissue can occur after an FNA procedure, making a definitive histological examination difficult or even impossible. When a preoperative FNAC is performed, the pathologist in charge should be advised accordingly. In addition, patients should be informed about this infrequent risk before undergoing the procedure.

Massive squamous metaplasia of the thyroid gland – Report of three cases

Three cases of massive squamous cell metaplasia in Hashimoto's thyroiditis are reported. The patients were two men and one woman aged 24, 52, and 55 years, respectively. In all three patients, the glandular parenchyma was replaced by hypocellular fibrous tissue with scattered chronic inflammatory infiltrate. Follicular cells were almost absent; the majority of residual epithelial cells formed squamous nests that were partly solid and partly cystic. There were three types of epithelial cells - squamous, basaloid, and follicular, with oncocytic differentiation. The squamous and basaloid cells showed strong positivity high molecular weight (HMW) cytokeratin, moderate to strong expression of galectin-3 (2/3), and nuclear expression of p63 protein (2/3). The staining pattern of p63 was identical to that of HMW, with predominant positivity at the periphery of cell nests. In one case, weak but unequivocal positivity of thyroid transcription factor-1 also was present. We believe that metaplasia was caused by Hashimoto's thyroiditis. The cases presented here are extremely rare, and only two convincing similar cases have been reported in the English literature so far. They may represent a diagnostic pitfall and should not be misdiagnosed as a malignancy, in particular as squamous cell or mucoepidermoid carcinoma.

Follicular thyroid lesions, elements that affect both diagnosis and prognosis

The precise diagnosis of follicular thyroid lesions is frequently debated because of the subjective nature of capsular invasion as well as both the histological and cytological characteristics. Furthermore, several different prognostic indices have been devised to examine prognosis associated with thyroid cancer. Herein, we describe how these confounding elements can affect the ability to accurately predict prognosis for patients with follicular thyroid lesions.

Spontaneous infarction of a pleomorphic adenoma in parotid gland: Diagnostic problems and review

Although infarction of parotid gland pleomorphic adenoma (PA) following fine-needle aspiration (FNA) has been well-documented, spontaneous infarction of PA has remained as an uncommon entity in the literature. To our knowledge, we report the second case of spontaneous infarction occurring in a parotid gland PA. A 44-yr-old man presented with a 2-yr history of slowly enlarging right parotid mass, which had become painful 1 mo before performing FNA biopsy. Smears revealed abundant necrotic debris, atypical squamous cells, and small cells with dark nuclei suggestive of a carcinoma. Histologic examination of the tissue fragments demonstrated degenerated clusters of cells and chondromyxoid matrix. The parotidectomy specimen had features consistent with those of an infarcted PA. Although appears to be rare, spontaneous infarction of PA should be considered in the differential diagnosis, since necrosis may mimic carcinoma and cause misinterpretation of necrosis as an indication of malignancy, in an otherwise benign salivary gland neoplasm.

Multiple parotid lymphoepithelial cysts in patients with HIV-infection: report of two cases

OBJECTIVE

Bilateral and multiple lymphoepithelial cysts (LECs) of major salivary glands, in particular of parotid glands, are quite rare and have been reported in human immunodeficiency virus (HIV) infected patients with an incidence of about 3-6%. These lesions represent an early manifestation of HIV infection and are rarely found in patients with advanced acquired immunodeficiency syndrome.

MATERIALS

Two cases of parotid LECs, the first occurring in a middle-age white woman and the second in a young white boy, both in advanced phases of HIV infection, are reported.

RESULTS

Clinical, cytological, histological and immunohistochemical (cytokeratin AE1/AE3, CD20, CD45RA, CD8, kappa and lambda immunoglobulin light chains, S-100, MLA and Ki67) features are described.

CONCLUSIONS

Fine needle aspiration (FNA), a relatively non-traumatic procedure, could represent both a diagnostic and a therapeutic tool in parotid LECs. No surgical therapy is usually required for these lesions and aspiration of cystic fluid with FNA is quite resolutive, although evidence of further relapses does exist. Surgical excision may become necessary when pain, because of persistent and progressive swelling of the parotid gland, occurs.

Fine-needle Aspiration Cytology in the Management of Salivary Gland Tumors: An Australian Experience

We conducted a retrospective study of 104 cases of salivary gland tumors that were initially assessed by fine-needle aspiration biopsy (FNAB). Based on subsequent histopathologic analysis of excised specimens, we found that preoperative FNAB was highly sensitive and specific for both benign and malignant tumors—including the most common, pleomorphic adenomas and squamous cell carcinomas, respectively. Despite its possible drawbacks, we conclude that preoperative FNAB is a useful tool in the management of salivary gland tumors.

Pleomorphic adenoma with extensive necrosis: report of two cases

Pleomorphic adenoma (PA) is the most common neoplasm for both the major and minor salivary glands. While PA is occasionally associated with cystic change or hemorrhage necrosis, spontaneous infarction appears to be very uncommon. We report two unusual cases of extensive necrosis of PA; one occurred in the palate with the necrotic tumor mass slipping into the oral cavity. This phenomenon, possibly associated with incision biopsy, has never been described previously. A second case, arising in the parotid with spontaneous tumor necrosis, poses some dilemma in differential diagnosis.

Diagnostic accuracy and pitfalls in fine-needle aspiration interpretation of Warthin tumor

BACKGROUND

Despite its well-defined histologic appearance, the often variegated cytomorphologic appearance of Warthin tumor (WT) on fine-needle aspiration (FNA) may lead to an erroneous cytopathologic interpretation. In this study, the authors analyzed the potential sources of diagnostic errors and overall accuracy of FNA diagnosis of WT.

METHODS

A retrospective search of The Johns Hopkins Hospital Surgical Pathology files (1985-2001) revealed 97 patients with WT, including 31 patients who underwent prior FNA. A comprehensive review of cytopathologic material was undertaken to calculate the overall accuracy of FNA and to identify sources of diagnostic error.

RESULTS

All tumors presented in the parotid gland. Four tumors (13%) were deemed inadequate for interpretation due to insufficient material. The FNA diagnosis of WT was rendered in only 20 tumors (74%). The remaining 7 tumors (26%) were misdiagnosed on FNA as consistent with or suspicious for carcinoma or some other neoplastic process. A retrospective review of the tumors, which were over-called on FNA, showed a predominance of necrotic or cellular debris (n = 6 tumors; 22%), significant epithelial metaplasia with atypia (n = 4 tumors; 15%), background inflammation suspicious for tumor diathesis (n = 3 tumors; 11%), spindle cells (n = 1 tumor; 4%), and abundant mucin with keratinized squamous cells (n = 1 tumor; 4%).

CONCLUSIONS

FNA is moderately accurate for diagnosing WT, with a 74% accuracy rate in the current series. Cytologic misinterpretation may occur due to a lack of characteristic cytomorphologic features of WT and overabundance of one or more of the following: squamous metaplasia/atypia, mucoid/mucinous background, spindle-shaped cells, and cystic/inflammatory debris. An adequate awareness of these potential sources of erroneous diagnoses, coupled with appropriate clinical findings, may result in a higher accuracy rate.

Clinical implications and value of immunohistochemical staining in the evaluation of lymph node infarction after fine-needle aspiration

We report on a series of 3 patients who underwent fine-needle aspiration (FNA) for clinically apparent lymphadenopathy. In all 3 cases, a diagnosis of malignancy was rendered based on cytologic findings (two metastatic squamous-cell carcinomas and one melanoma). However, initial follow-up surgical pathology reported only "extensive coagulative necrosis, no viable tumor seen." Subsequent immunohistochemical stains (cytokeratins (AE1/AE3), HMB45, S100, and Melan A) demonstrated the presence of metastatic tumor in the area of infarction in each case, thus establishing the presence of metastatic tumor and correct interpretation of the initial FNA. We conclude, based on our own experience and a few previously reported cases, that total infarction of the lymph nodes following FNA can occur, and immunohistochemistry can be helpful in clinical management.