Prognostic factors in metaplastic carcinoma of the breast: a multi-institutional study.

BACKGROUND: Metaplastic breast carcinoma (MBC) is a rare type of breast cancer that has basal-like characteristics and is perceived to have poorer prognosis when compared with conventional no specific type/ductal carcinomas (ductal/NST). However, current data on MBC are largely derived from small case series or population-based reports. This study aimed to assess the clinicopathological features and outcome of MBC identified through an international multicentre collaboration. METHODS: A large international multicentre series of MBC (no=405) with histological confirmation and follow-up information has been included in this study. The prognostic value of different variables and outcome has been assessed and compared with grade, nodal status and ER/HER2 receptor-matched ductal/NST breast carcinoma. RESULTS: The outcome of MBC diagnosed in Asian countries was more favourable than those in Western countries. The outcome of MBC is not different from matched ductal/NST carcinoma but the performance of the established prognostic variables in MBC is different. Lymph node stage, lymphovascular invasion and histologic subtype are associated with outcome but tumour size and grade are not. Chemotherapy was associated with longer survival, although this effect was limited to early-stage disease. In this study no association between radiotherapy and outcome was identified. Multivariate analysis of MBC shows that histologic subtype is an independent prognostic feature. CONCLUSIONS: This study suggests that MBC is a heterogeneous disease. Although the outcome of MBC is not different to matched conventional ductal/NST breast carcinoma, its behaviour is dependent on the particular subtype with spindle cell carcinoma in particular has an aggressive biological behaviour. Management of patients with MBC should be based on validated prognostic variables.

Subtyping of triple-negative breast cancers: its prognostication and implications in diagnosis of breast origin.

BACKGROUND: Triple-negative breast cancer (TNBC) subtyping by gene profiling has provided valuable clinical information. Here, we aimed to evaluate the relevance of TNBC subtyping using immunohistochemistry (IHC), which could be a more clinically practical approach, for prognostication and applications in patient management. METHODS: A total of 123 TNBC cases were classified using androgen receptor (AR), CD8, Forkhead box C1 protein (FOXC1), and doublecortin-like kinase 1 (DCLK1) into luminal androgen receptor (LAR), basal-like immunosuppressive (BLIS), mesenchymal-like (MES), and immunomodulatory (IM) subtypes. The IM cases were further divided into the IM-excluded and IM-inflamed categories by CD8 spatial distribution. Their clinicopathological and biomarker profiles and prognoses were evaluated. RESULTS: LAR (28.6%) and MES (11.2%) were the most and least frequent subtypes. The IHC-TNBC subtypes demonstrated distinct clinicopathological features and biomarker profiles, corresponding to the reported features in gene profiling studies. IM-inflamed subtype had the best outcome, while BLIS had a significantly poorer survival. Differential breast-specific marker expressions were found. Trichorhinophalangeal syndrome type 1 (TRPS1) was more sensitive for IM-inflamed and BLIS, GATA-binding protein 3 (GATA3) for IM-excluded and MES, and gross cystic disease fluid protein 15 (GCDFP15) for LAR subtypes. CONCLUSIONS: Our findings demonstrated the feasibility of IHC surrogates to stratify TNBC subtypes with distinct features and prognoses. The IM subtype can be refined by its CD8 spatial pattern. Breast-specific marker expression varied among the subtypes. Marker selection should be tailored accordingly.

The role of immunohistochemistry for smooth-muscle actin, p63, CD10 and cytokeratin 14 in the differential diagnosis of papillary lesions of the breast.

BACKGROUND: Histological differentiation of mammary papillary lesions can be difficult. The evaluation of myoepithelial cells can be helpful, with benign papilloma showing a continuous myoepithelial cell layer, which becomes attenuated or absent in malignant papillary lesions. METHODS: A large series of 100 papillomas (28 papillomas with florid epithelial hyperplasia) and 68 papillary carcinomas (9 invasive, 44 in situ, and 15 ductal carcinomas in situ (DCIS) involving papillomas) of the breast were stained for myoepithelial cells by immunohistochemistry using antibodies to smooth-muscle actin (SMA), p63, CD10 and cytokeratin (CK) 14. RESULTS: In the papillomas, using these four antibodies, myoepithelial cells were positive in 88%, 99%, 91% and 95% of cases, respectively, with SMA showing marked stromal component cell staining and CD10 showing epithelial and stromal staining. CK14 also showed epithelial staining in 71% of papillomas and 96% of papillomas with florid epithelial hyperplasia. In the papillary carcinomas, 36 (53%) cases showed staining of myoepithelial cells that were scattered, discontinuous and diminished in number and the remaining 32 (47%) cases did not show myoepithelial cells. Invasive papillary carcinoma has the lowest proportion (33%) with myoepithelial cells, and DCIS involving papillomas had the highest proportion (87%). CONCLUSIONS: p63 had the highest sensitivity and did not cross-react with stromal cells and only rarely with epithelial cells. CK14 has the added ability to distinguish between florid epithelial hyperplasia involving papilloma and DCIS involving papillomas. CK14 and p63 may be used as an adjunct in assessing difficult papillary lesions of the breast.

Metaplastic carcinoma of the breast: a clinicopathological review.

BACKGROUND: Mammary metaplastic carcinoma encompasses epithelial-only carcinoma (high-grade adenosquamous carcinoma or pure squamous cell carcinoma), biphasic epithelial and sarcomatoid carcinoma and monophasic spindle cell carcinoma. AIM: To evaluate the clinicopathological features of a large series of 34 metaplastic carcinomas. METHODS: 10 epithelial-only, 14 biphasic and 10 monophasic metaplastic carcinomas were assessed for nuclear grade, hormone receptor status, HER2/neu (cerbB2) oncogene expression, Ki-67 and p53, lymph node status and recurrence on follow-up. RESULTS: Intermediate to high nuclear grade were assessed in most (33/34) tumours. Oestrogen and progesterone receptors were negative in 8 of 10 epithelial-only, all 14 biphasic, and 9 of 10 monophasic tumours, cerbB2 was negative in 7 of 10 epithelial-only, all 14 biphasic and 8 of 10 monophasic tumours. Ki-67 was found to be positive in 6 of 10 epithelial-only, 6 of 14 biphasic, and 7 of 10 monophasic tumours, whereas p53 was positive in 6 of 10 epithelial-only, 7 of 14 biphasic, and 8 of 10 monophasic tumours. Lymph node metastases were seen in 7 of 7 epithelial-only, 7 of 11 biphasic, and 3 of 7 monophasic tumours. Recurrences were seen in 4 of 7 epithelial-only, 8 of 9 biphasic, and 4 of 9 monophasic tumours. CONCLUSIONS: All three subtypes of metaplastic carcinoma are known to behave aggressively, and should be differentiated from the low-grade fibromatosis-like metaplastic carcinoma, which does not metastasize. Oncological treatment options may be limited by the frequently negative status of hormonal receptor and cerbB2.

Biopsy of deep-seated head and neck lesions under intraoral ultrasound guidance.

Although transcutaneous ultrasound combined with fine-needle aspiration is often used as initial modality for evaluating superficial neck masses, its role in management of deep-seated neck masses is limited. Intraoral ultrasound and guided biopsy helps in obtaining tissue from deep-seated neck masses for an accurate histologic diagnosis, providing useful information in treatment planning. This article discusses the role of intraoral ultrasound and presents 3 cases in which biopsy of deep-seated neck masses under intraoral ultrasound guidance helped in diagnosis and management.

High frequency of chromosome 3p deletion in histologically normal nasopharyngeal epithelia from southern Chinese.

We have examined the presence of loss of heterozygosity (LOH) on chromosome 3p in histologically normal nasopharyngeal epithelia (NP), dysplastic lesions, and carcinoma of the nasopharynx from different ethnic and geographic regions. Microdissected normal NP from noncancerous individuals and nasopharyngeal carcinoma (NPC) samples from both the high-risk group (southern Chinese in Hong Kong) and two low-risk groups for NPC (central/northern Chinese in Anhui/Beijing and Caucasians in Toronto) were included. All NPC samples showed high incidence of 3p deletion (81-100%). High frequencies of LOH on 3p were also detected in normal NP (73.9%) and dysplastic lesions (75%) from the southern Chinese. Significant lower frequency of LOH on 3p was noted in normal NP from the low-risk groups (20%) than those from high-risk groups (P = 0.0003). The presence of such genetic alterations in the histologically normal NP and dysplastic lesions suggests that it is an early event in tumor development. The higher frequency of 3p LOH found in normal NP from southern Chinese compared with those from low-risk groups may be related to the distinct cancer incidence among these populations.

CD44s is useful in the differentiation of benign and malignant papillary lesions of the breast.

BACKGROUND/AIMS: CD44s, the standard form of CD44, has been shown to be downregulated during malignant transformation of breast cancers. It has also been reported recently to be a useful marker in differentiating between benign and malignant papillary lesions of the breast, with high expression in the former. CD44s expression in benign and malignant papillary lesions was evaluated. METHODS: CD44s expression was assessed by immunohistochemistry in 101 benign papillomas and 59 papillary carcinomas (seven invasive papillary carcinomas, 41 papillary ductal carcinomas in situ, and 11 ductal carcinomas involving papillomas). RESULTS: Patients' age and tumour size were significantly different between the papilloma and papillary carcinoma groups (p < 0.0001). CD44s showed positive staining in 45 papillomas (45%) and five papillary carcinomas (8%), and the difference was significant (p < 0.0001). The myoepithelial cells, when present, were also positive for CD44s in both groups, with no observable differences. Using CD44s positive staining to differentiate between benign and malignant papillary lesions gives a sensitivity, specificity, and accuracy of 45%, 92%, and 62%, respectively. CONCLUSIONS: CD44s may be useful as an adjunct in the evaluation of morphologically problematic cases of papillary lesion of the breast.

Stromal CD10 expression in mammary fibroadenomas and phyllodes tumours.

BACKGROUND/AIMS: CD10 (CALLA) has recently been reported to be expressed in spindle cell neoplasia, and has been used to differentiate endometrial stromal sarcoma from leiomyoma and leiomyosarcoma. In the breast, myoepithelial cells express CD10, but there are few studies of the expression of CD10 in mammary fibroepithelial lesions. METHODS: Stromal CD10 expression was studied in 181 mammary phyllodes tumours (102 benign, 51 borderline malignant, and 28 frankly malignant) and 33 fibroadenomas using immunohistochemistry, to evaluate whether differences in expression correlated with the degree of malignancy. RESULTS: There was a progressive increase in the patients' age and tumour size, from fibroadenoma to phyllodes tumours with an increasing degree of malignancy (p < 0.001). Stromal CD10 expression was positive in one of 33 fibroadenomas, six of 102 benign phyllodes tumours, 16 of 51 borderline malignant phyllodes tumours, and 14 of 28 frankly malignant phyllodes tumours. The difference was significant (p < 0.001) and an increasing trend was established. Strong staining was seen in subepithelial areas with higher stromal cellularity and activity. Stromal CD10 expression had a high specificity (95%) for differentiating between benign lesions (fibroadenomas and benign phyllodes tumours) and malignant (borderline and frankly malignant) phyllodes tumours. CONCLUSIONS: CD10 may be a useful adjunct in assessing malignancy in mammary fibroepithelial lesions.

Stromal nitric oxide synthase (NOS) expression correlates with the grade of mammary phyllodes tumour.

BACKGROUND: Nitric oxide synthase (NOS), particularly endothelial and inducible forms (e/i-NOS), are expressed in various cancers, including breast cancer. In mammary fibroepithelial lesions, NOS expression in stromal cells has been reported to be lower in fibroadenomas than in phyllodes tumours. AIMS: To investigate NOS expression in phyllodes tumours of varying degrees of malignancy. METHODS: One hundred and sixty seven mammary phyllodes tumours (97 benign, 47 borderline malignant, and 23 frankly malignant) were evaluated for e-NOS and i-NOS expression by immunohistochemistry. Correlations with previously reported expression of stromal vascular growth factor (VEGF) and microvessel density were also performed. RESULTS: Stromal expression of e-NOS was absent, weak, moderate, and strong in 43%, 31%, 13%, and 13% of benign tumours; 17%, 26%, 13%, and 44% of borderline malignant tumours; and 17%, 35%, 13%, and 35% of frankly malignant tumours, respectively. Stromal expression of i-NOS was 77%, 18%, 4%, and 1% in benign tumours; 42%, 28%, 19%, and 11% in borderline malignant tumours; and 43%, 13%, 26%, and 18% in frankly malignant tumours, respectively. Stromal expression of both i-NOS and e-NOS was significantly different between the benign and malignant (borderline and frank) groups of phyllodes tumours (p < 0.0001). Furthermore, the expression of i-NOS correlated with stromal VEGF expression and microvessel density. The expression of NOS in the epithelial cells was strong, and showed no differences between the different groups of tumours. CONCLUSIONS: Higher stromal expression of NOS in phyllodes tumours is associated with malignancy, suggesting a possible role in malignant progression, particularly metastasising potential.

Ductal carcinoma in situ arising in mammary hamartoma.

Hamartoma of the breast is an uncommon lesion. Although it can possess characteristic radiological features, the pathological appearance is not distinctive. Hamartoma is generally considered benign, but four cases have been reported with ductal and lobular carcinoma arising in hamartomas. This report describes further cases of hamartoma from which ductal carcinoma in situ arose, with one showing early invasion. In both cases, the tumours were within the hamartomas and were adequately excised during lumpectomies of the hamartomas, and the patients were well afterwards. This report emphasises the importance of adequate sampling of mammary hamartoma.

Intravascular lymphomatosis.

Intravascular lymphomatosis (IVL) is a rare angiotrophic large cell lymphoma producing vascular occlusion of arterioles, capillaries, and venules. Antigenic phenotyping shows that these lymphomas are mostly of B cell type, and less commonly T cell or Ki-1 lymphomas. The central nervous system and skin are the two most commonly affected organs; patients usually present with progressive encephalopathy with mental status changes and focal neurological deficits and skin petechia, purpura, plaques, and discolouration. Other involved organs include adrenal glands, lungs, heart, spleen, liver, pancreas, genital tract, and kidneys. Bone marrow, blood, cerebrospinal fluid, and lymph nodes are typically spared. Fever of unknown origin is another common presentation. Only one case of IVL presenting with disseminated intravascular coagulation and anasarca (generalised oedema) has been reported in the literature. This report describes a postmortem case of a patient with IVL who initially presented with disseminated intravascular coagulation complicated by intracerebral haemorrhage.

Pulmonary tumour microembolism clinically mimicking alveolitis.

A 56 year old man with previously unsuspected recurrence of squamous cell carcinoma of the oesophagus presented with dyspnoea. Bronchoscopy and computed tomography suggested bronchopneumonic changes with an infectious cause. He suffered a rapidly deteriorating course and died despite active treatment, including antibiotics and mechanical ventilation. Necropsy revealed a florid pulmonary tumour microembolism mimicking alveolitis. No bronchopneumonia was seen. The emboli arose from loosely attached tumour vegetations in the tricuspid valve. In a patient with known malignancy, tumour microembolism should be considered as an uncommon cause of rapid respiratory failure, refractory to antibiotic treatment.

Fine needle aspiration cytology of granulomatous mastitis.

AIMS: Granulomatous mastitis (GM) is an uncommon breast lesion that mimics carcinoma. The fine needle aspiration cytological (FNAC) features of GM have rarely been discussed in the literature. These features are reported in eight histologically confirmed cases of GM. METHODS: A retrospective study was undertaken in which a diagnosis of GM had been made on histopathology, and the FNAC slides were reviewed and assessed for the presence of granulomas, necrosis, multinucleated giant cells, and inflammatory background cells. Polymerase chain reaction (PCR) for Mycobacterium tuberculosis was performed on the histological material to exclude tuberculosis. RESULTS: All cases were confirmed histologically and PCR for mycobacterial DNA was negative. In the FNACs, varying numbers of granulomas composed of epithelioid histiocytes were present in four cases. The same four cases showed giant cells of either foreign body or Langhan's type. No necrosis was noted. Six cases showed many histiocytes, some plump and others epithelioid, in the background. The number of epithelioid histiocytes corresponded to the presence of granulomas. Neutrophils were the predominant background inflammatory cells in most cases (six). CONCLUSIONS: The cytological diagnosis of GM is difficult because the features overlap with other aetiologies, including tuberculosis. Specific features are absent. The absence of necrosis and a predominantly neutrophilic infiltrate in the background favour a diagnosis of GM. This diagnosis should also be considered when abundant epithelioid histiocytes are seen in smears, even in the absence of granulomas. However, the definitive diagnosis of GM depends on histology from fine needle biopsies and negative microbiological investigations.

Sputum cytology of patients with severe acute respiratory syndrome (SARS).

BACKGROUND: Severe acute respiratory syndrome (SARS) is a newly described form of atypical pneumonia linked to a novel coronavirus. AIMS: To review the sputum cytology of 15 patients who fulfilled the World Health Organisation clinical criteria for SARS in an attempt to evaluate whether early diagnosis is feasible with routine sputum examination. METHODS: All sputum samples from patients with SARS from the four major hospitals in Hong Kong were reviewed; abnormalities were sought in the cellular component, including abnormal numbers and morphology of the component cells compared with those from age matched controls taken over the same period one year ago. RESULTS: Fifteen sputum samples from patients were compared with 25 control samples. In the patients with SARS, loose aggregates of macrophages were seen more frequently in the sputum. These macrophages frequently showed morphological changes, such as cytoplasmic foaminess, vacuole formation, and nuclear changes (including multinucleation and a ground glass appearance) when compared with the control samples. CONCLUSIONS: The cytological features of SARS are non-specific, but the observation of any of the described features should prompt further investigations, especially in patients with suspicious clinical features.

Hamartoma of the breast: a clinicopathological review.

AIMS: To review 25 cases of breast hamartoma and discuss the pathological criteria, and the usefulness of imaging modalities, fine needle aspiration cytology (FNAC), and needle core biopsy in the diagnosis. METHODS: The hamartomas were assessed for interlobular fibrotic stroma, stromal adipose tissue content, pseudo-angiomatous stromal hyperplasia, and epithelial changes (hyperplasia, adenosis or apocrine metaplasia, and cyst formation). All imagings, previous FNACs, and biopsies were also reviewed. RESULTS: Imaging (mammography, ultrasound, and magnetic resonance imaging) was performed in 18 cases, and mostly showed encapsulated masses with a heterogeneous appearance. Microscopically, all hamartomas demonstrated good demarcation with fibrous tissue condensation. Adipose tissue was noted in all cases (5-90%; mean, 31%), and interlobular fibrosis in 21 cases. Benign epithelial hyperplasia occurred in 10 cases, and pseudo-angiomatous stromal hyperplasia or cystic ducts in eight cases each. Apocrine metaplasia, calcification, stromal giant cells, and adenosis occurred in four cases or less. Two cases showed coexisting ductal carcinoma in situ limited to within the hamartoma. Needle core biopsies (four cases) and FNAC (14 cases) were largely insufficient, inconclusive, or non-specific. CONCLUSIONS: Hamartomas do not possess specific diagnostic histological features. The role of FNAC and needle core biopsy in making the diagnosis is limited, and requires clinical and radiological correlation to avoid underdiagnosis.

Pulmonary pathological features in coronavirus associated severe acute respiratory syndrome (SARS).

BACKGROUND: Severe acute respiratory syndrome (SARS) became a worldwide outbreak with a mortality of 9.2%. This new human emergent infectious disease is dominated by severe lower respiratory illness and is aetiologically linked to a new coronavirus (SARS-CoV). METHODS: Pulmonary pathology and clinical correlates were investigated in seven patients who died of SARS in whom there was a strong epidemiological link. Investigations include a review of clinical features, morphological assessment, histochemical and immunohistochemical stainings, ultrastructural study, and virological investigations in postmortem tissue. RESULTS: Positive viral culture for coronavirus was detected in most premortem nasopharyngeal aspirate specimens (five of six) and postmortem lung tissues (two of seven). Viral particles, consistent with coronavirus, could be detected in lung pneumocytes in most of the patients. These features suggested that pneumocytes are probably the primary target of infection. The pathological features were dominated by diffuse alveolar damage, with the presence of multinucleated pneumocytes. Fibrogranulation tissue proliferation in small airways and airspaces (bronchiolitis obliterans organising pneumonia-like lesions) in subpleural locations was also seen in some patients. CONCLUSIONS: Viable SARS-CoV could be isolated from postmortem tissues. Postmortem examination allows tissue to be sampled for virological investigations and ultrastructural examination, and when coupled with the appropriate lung morphological changes, is valuable to confirm the diagnosis of SARS-CoV, particularly in clinically unapparent or suspicious but unconfirmed cases.

Multinucleated stromal giant cells in mammary phyllodes tumours.

Mammary phyllodes tumour (PT) is an uncommon fibroepithelial neoplasm with a prominent stromal component. We report five cases of PT (one benign, three borderline, one malignant) with giant cells in the stroma. All occurred in adults and ranged from 1.8 to 4.0 cm in size. The overall cellularity, stromal cell pleomorphism and mitotic count was higher for the malignant and borderline than the benign PT. The giant cell number ranged from 18 to 35 cells per 10 high power fields, but there was no relationship between this number and the grade of the PT. Most giant cells were subepithelial, with multiple nuclei arranged in a linear or irregular pattern, and moderate amount of cytoplasm. The immunohistochemical profile of the giant cells was similar to the stromal cells. In all cases, both giant cells and stromal cells expressed vimentin strongly but not desmin; in two cases, both cell populations expressed actin weakly. The respective percentage of giant cells and stromal cells expressing MIB1 was also similar. This suggests that these giant cells do not represent a different, more active stromal population, despite the more bizarre appearance. In view of the small number of cases, the significance of such giant cells on the prognosis of PT remains uncertain.

Fibromatosis of the head and neck region.

OBJECTIVE: Five cases of head and neck fibromatosis were analyzed. The imaging and pathologic findings, surgical management, and clinical outcome were discussed. STUDY DESIGN AND SETTING: A retrospective study of 5 adult head and neck fibromatosis cases, evaluating long-term follow-up results of conservative treatment. RESULTS: The 5 patients (2 male and 3 female) ranged in age from 16 to 51 years. The lesion size ranged from 1 to 8 cm. Four cases had limited surgical resection; 1 case was followed only. One of the surgically treated cases had a recurrence that was irradiated. All patients were well for a follow-up period of 2 to 8 years. CONCLUSION: Aggressive excision of head and neck fibromatosis cannot be achieved easily. Vigilant follow-up with or without conservative surgical excision achieves good disease control. Low dose radiotherapy can be used for inoperable cases. SIGNIFICANCE: Judicious conservative treatment should be attempted for head and neck fibromatosis to achieve optimal functional preservation.

Fine needle aspiration cytology of invasive micropapillary carcinoma of the breast. A case report.

BACKGROUND: Invasive micropapillary carcinoma of the breast is uncommon and was characterized only recently. Awareness of this entity and its cytologic appearance is important to allow early diagnosis by fine needle aspiration cytology (FNAC). To our knowledge, only two cases of FNAC of this lesion have been reported in the English-language literature. CASE: An 80-year-old female presented with a firm, nontender mass in the upper outer quadrant of the left breast. FNAC showed ductal carcinoma, and mastectomy showed invasive micropapillary carcinoma. The patient had axillary metastases and received tamoxifen. CONCLUSION: The cytologic features of invasive micropapillary carcinoma are distinctive, with clusters of cells showing hyperchromatic, irregular and crowded nuclei and peripherally located cytoplasm with a rare central lumen. Fibrovascular cores are absent. Although FNAC experience with this lesion is limited, the characteristic cytologic features, including "inside-out" cell clusters, should raise the suspicion of this variant of ductal carcinoma. Differentiation from other papillary lesions and malignancies may be possible, but more experience is needed as the number of reported cases remains limited.

Basal cell adenocarcinoma of the salivary gland: report of a case with morphology on fine needle aspiration cytology.

BACKGROUND: Basal cell adenocarcinoma of the parotid is rare and prone to recur. CASE: A 54-year-old woman had a history of afacial mass 12 years earlier that had been excised and was diagnosed as low grade adenocarcinoma of the parotid. Over the years, the patient had multiple local and lymph node recurrences. Histology of the excised local recurrent tumor showed basal cell adenocarcinoma, and FNAC of a separate recurrent nodule was performed. The aspirate showed moderate cellularity of basaloid cells with mildly pleomorphic nuclei, small nucleoli and occasional mitotic figures. The cells were mostly single, but some formed clusters with a rosettelike pattern of tumor cells surrounding central eosinophilic globules. A second, less prominent population of smaller cells with dark-staining nuclei was also noted. The differential diagnosis included adenoid cystic carcinoma, polymorphous low grade adenocarcinoma, and basal cell and pleomorphic adenoma. CONCLUSION: The cytologic features of basal cell adenocarcinoma are not distinctive, but the presence of two cell populations with moderate pleomorphism and a rosettelike pattern with central, eosinophilic globules may assist with its differentiation from other salivary gland neoplasms.