Mast cell tumours in dogs less than 12 months of age: a multi-institutional retrospective study.

OBJECTIVES: To describe the clinicopathological and genetic characteristics of mast cell tumours in dogs less than 12 months old. MATERIALS AND METHODS: Retrospective review of dogs aged less than 12 months when diagnosed with mast cell tumours at three referral hospitals in the UK. RESULTS: Sixteen pure-bred dogs were included, of which 11 were female. The median age at first presentation and diagnosis were 7.6 and 9 months, respectively. In 13 dogs the mast cell tumours were cutaneous and in three they were subcutaneous. Four cutaneous mast cell tumours were described as high-grade (Patnaik or Kiupel) and nine were Patnaik grade II; three had mitotic index of >5 in 10 high-power fields. Of the three subcutaneous tumours, two had an infiltrative growth pattern and one had mitotic index of 10 per 10 high-power fields. Of 10 tested dogs, seven had c-kit mutations in exon 11 and Ki-67 score was above the cut-off value in nine. Four of 12 cases showed evidence of metastasis in the regional lymph nodes. After varying treatment protocols, all patients were alive and disease free at a median of 1115 days after diagnosis. CLINICAL SIGNIFICANCE: The prognosis of mast cell tumours in dogs less than a year old appears better than the adult counterparts, even without extensive treatment.

Tumour-to-tumour metastasis: breast carcinoma to an olfactory neuroblastoma.

Tumour-to-tumour metastasis is a rare phenomenon. It occurs when a primary tumour is a recipient of a separate tumour within the same individual. We present a case of a 66-year-old woman with known breast cancer who presented with one-sided nasal symptoms. Examination and imaging revealed a unilateral polyp arising from the skull base. She underwent endoscopic polypectomy with the histology demonstrating tumour-to-tumour metastasis from a breast carcinoma to an olfactory neuroblastoma, a rare sinonasal tumour. Clinicians should be cautious of distant metastases in any patient presenting with head and neck symptoms and a known primary tumour. This is the first documented case of this type.

IgG4 related sclerosing sialadenitis- a retrospective analysis.

BACKGROUND: IgG4 related disease rarely affects the salivary glands and clinically is often confused with salivary gland malignancy. METHOD: This is a retrospective study comprising 137 cases of chronic sialadenitis diagnosed in a histopathology department over 4 years. The morphology was assessed by reviewing the histology slides and the incidence of IgG4 related sclerosing sialadenitis was calculated. IgG and IgG4 immunohistochemistry was performed and mean IgG4 count/hpf and IgG4/IgG ratio were determined. Clinical findings were obtained from medical records. RESULTS: Of the 137 cases reviewed, 3 cases showed diagnostic histological features of IgG4 related sialadenitis, these being: a prominent lymphoplasmacytic infiltrate, lobular fibrosis, acinar atrophy, obliterative phlebitis and mean IgG4 count of 86/hpf with mean IgG4/IgG ratio 65%. No further disease was documented at follow-up which ranged from 24 to 36 months. CONCLUSION: The incidence of IgG4 related sialadenitis in the present study is 2%, indicating that it is a rare condition. Since there is no non-invasive diagnostic modality, either core biopsy or surgical excision is required for definitive histological diagnosis.

Level 5 Lymphadenopathy Warrants Heightened Suspicion for Clinically Significant Pathology.

We conclude that patients presenting with level 5 lymphadenopathy should be investigated with heightened clinical vigilance. Our results suggest that up to 80 % will harbour clinically significant pathology requiring further medical treatment, three quarters of which will be malignancy. We report an observational study of histological outcomes of level 5 lymph node biopsies from a regional histopathology department across 5 years. 184 subjects were identified as having a biopsy of a lymph node from the level 5 region within the study period. One hundred and fifty six cases (84.8 %) had clinically significant pathology on final histology requiring further medical treatment. Lymphoma accounted for the highest number of cases (n = 72, 39.1 %), followed by metastatic carcinoma (n = 65, 35.3 %) and granulomatous change (n = 17, 9.2 %). Gender and laterality were not shown to be independent predictors of pathology significance (p > 0.05).

Concordance of c-kit mutational status in matched primary and metastatic cutaneous canine mast cell tumors at baseline.

BACKGROUND: Mutation analysis of proto-oncogene c-kit (c-kit) is advisable before starting treatment with tyrosine kinase inhibitors in dogs with mast cell tumor (MCT), including those with metastatic disease. Testing is usually performed on primary tumors, assuming that c-kit mutation status does not change in metastasis. HYPOTHESIS/OBJECTIVES: To give an insight into the mutational processes and to make a recommendation on the use of c-kit mutational analysis in the clinical setting. ANIMALS: Twenty-one client-owned dogs with metastatic MCT. METHODS: Dogs undergoing resection or biopsy for both primary and matched metastatic MCT were prospectively enrolled. Total RNA or DNA was extracted from primary MCT and corresponding metastases. Exons 8, 9, and 11 were amplified by PCR and sequenced. Genetic features between primary MCT and metastases were compared. Their correlation with clinicopathologic features was investigated. RESULTS: Concordance (mutated or wild-type) of mutational status, evaluable in 21 primary and matched metastatic (20 nodal and 1 splenic) MCTs, was 100%. Three new c-kit mutations were identified. No significant correlation was detected between c-kit mutation and clinicopathologic features. CONCLUSIONS AND CLINICAL IMPORTANCE: Proto-oncogene c-kit mutational status is conserved between any primary and its matched secondary tumor, suggesting that both can be used for c-kit mutational testing. Targeted therapies might be also used to treat metastatic disease.

Immunolocalisation of heme oxygenase isoforms in human nasal polyps.

BACKGROUND: Carbon monoxide is an endogenous vasodilator gas produced by the enzyme heme oxygenase (HO). HO is expressed in human nasal mucosa, but its pathophysiological role in nasal inflammatory diseases is not fully understood. The aim of this study was to detect and compare the expression of HO-1 and -2 isoforms in nasal polyps with normal nasal mucosa. METHODS: Immunohistochemical analysis using antibodies specific for HO-1 and -2 was conducted on nasal polyps from nine patients with allergic nasal polyposis, and on normal nasal mucosa from six controls. RESULTS: Intense HO-1 immunoreactivity was observed in nasal polyp epithelium but was absent in normal nasal mucosa. HO-2 staining was observed in respiratory epithelium, vascular endothelium and seromucous glands, with no difference observed between nasal polyps and normal nasal mucosa. CONCLUSIONS: HO-1 expression is up-regulated in nasal polyp epithelium, supporting the theory that respiratory epithelium plays a role in the pathogenesis of nasal polyposis.

Salivary duct carcinoma in situ of the parotid gland.

AIMS: To describe three cases of purely in situ salivary duct carcinoma, so as better to define the entity. METHODS AND RESULTS: Three primary tumours of the parotid gland are presented, in each case composed of cysts and ducts and lined by high nuclear grade epithelial cells. All parts of each tumour were surrounded by a myoepithelial cell rim and there was no evidence of invasion. The tumour cells expressed immunohistochemical markers seen in invasive salivary duct carcinoma of usual (high-grade) type. In two cases the androgen receptor (AR) reaction was strong, but there was no immunohistochemical expression of HER2 protein or gene amplification by in situ hybridization. In the remaining case, fewer nuclei stained for AR, but both HER2 protein and gene amplification were demonstrated. CONCLUSIONS: Salivary duct carcinoma in situ is morphologically similar to breast ductal carcinoma in situ and, although our cases are few, salivary duct carcinoma in situ can possibly be subdivided into luminal and non-luminal cell types, as can analogous mammary neoplasms. The present study cannot determine whether low-grade cribriform cystadenocarcinoma, architecturally similar but immunohistochemically different, is part of the spectrum of salivary duct carcinoma in situ, or whether it represents a separate entity.

Pathology of sentinel lymph nodes for melanoma.

As a concept sentinel lymph node biopsy seems attractive in that it attempts to identify the first lymph node, rather than the nearest node, draining a particular anatomic area where a tumour has arisen. Pathological assessment can then indicate whether metastases are present and the procedure is either a strong prognostic indicator or possibly therapeutic in itself. These comments apply to any tumour type, but with melanoma the pathological procedure is more problematic and any benefits above prognosis and staging are not universally accepted. The procedure does give accurate staging without the extra morbidity of regional node dissection and many patients gain psychological support from the information gained.

Genomic and immunophenotypical characterization of pure micropapillary carcinomas of the breast.

Pure invasive micropapillary carcinoma (MPC) is a special histological type that accounts for 0.7-3% of all breast cancers. MPC has a distinctive growth pattern and a more aggressive clinical behaviour than invasive ductal carcinomas of no special type (IDC-NSTs). To define the molecular characteristics of MPCs, we profiled a series of 12 MPCs and 24 grade and oestrogen receptor (ER)-matched IDC-NSTs using high-resolution microarray comparative genomic hybridization (aCGH). In addition, we generated a tissue microarray containing a series of 24 MPCs and performed immunohistochemical analysis with ER, PR, Ki-67, HER2, CK5/6, CK14, CK17, EGFR, topoisomerase-IIalpha, cyclin D1, caveolin-1, E-cadherin, and beta-catenin antibodies. In situ hybridization probes were employed to evaluate the prevalence of amplification of HER2, TOP2A, EGFR, CCND1, MYC, ESR1, and FGFR1 genes. aCGH analysis demonstrated that MPCs significantly differed from IDC-NSTs at the genomic level. Gains of 1q, 2q, 4p, 6p, 6q23.2-q27, 7p, 7q, 8p, 8q, 9p, 10p, 11q, 12p, 12q, 16p, 17p, 17q, 19p, 20p, 20q, and 21q, and losses of 1p, 2p, 6q11.1-q16.3, 6q21-q22.1, 9p, 11p, 15q, and 19q were more prevalent in MPCs. High-level gains/amplifications of 8p12-p11, 8q12, 8q13, 8q21, 8q23, 8q24, 17q21, 17q23, and 20q13 were significantly associated with MPCs. A comparison between 24 MPCs and a series of 48 grade and ER-matched IDC-NSTs revealed that high cyclin D1 expression, high proliferation rates, and MYC (8q24) amplification were significantly associated with MPCs. Our results demonstrate that MPCs have distinct histological features and molecular genetic profiles supporting the contention that they constitute a distinct pathological entity.

A quality assurance exercise to evaluate the accuracy and reproducibility of chromogenic in situ hybridisation for HER2 analysis in breast cancer.

BACKGROUND: Chromogenic in situ hybridisation (CISH) is an alternative to immunohistochemistry or FISH for the assessment of HER2 oncogene status in breast cancer. Although CISH is being used increasingly in routine diagnostics, there are no established inter-laboratory quality assurance programmes for this test. METHODS: The reproducibility of HER2 CISH analysis was assessed when performed by seven different centres that use the test routinely in diagnostic service. RESULTS: The results from 28 cases showed overall concordance of 98.5% (192/195 tests; kappa coefficient 0.91). One of the discrepancies was due to the invasive carcinoma having been cut out in the sections received by two of the centres, and the other two were in the non-amplified/equivocal/low-amplified category. CONCLUSION: This is believed to be the first report of a quality assurance study assessing laboratories that use HER2 CISH routinely in clinical diagnostics. The results show that CISH is a robust technique providing a suitable assay for the frontline testing of HER2 status in breast cancer.

Patients with advanced stage breast carcinoma immunoreactive to biotinylated Herceptin are most likely to benefit from trastuzumab-based therapy: an hypothesis-generating study.

BACKGROUND: Biotin-labeled trastuzumab (BiotHER) can be used to test for HER2 by immunohistochemistry. We previously showed that BiotHER immunoreactivity is highly correlated with HER2 amplification and indicated that it could be associated with better clinical outcome in advanced breast cancer patients receiving trastuzumab. PATIENTS AND METHODS: Tumor specimens and clinical information from 234 patients who received trastuzumab-based treatments were collected from 10 institutions. HER2 amplification and BiotHER immunoreactivity were assessed centrally. The effect of BiotHER positivity on response rate (RR), time to progression and survival were studied by univariate and multivariate analysis in patients presenting HER2-amplified breast cancer. The pathologic reviews of the assays were blinded to patient outcomes. RESULTS: BiotHER was positive in 109/194 (56%) HER2-amplified breast cancers and in one not amplified tumor. RRs were 74% [95% (confidence interval) CI 64%-81%] and 47% (95% CI 36%-58%) in BiotHER-positive and -negative tumors, respectively (P < 0.001). BiotHER immunoreactivity was independently associated with increased probability of tumor response (odds ratio 3.848; 95% CI 1.952-7.582), with reduced risk of disease progression [hazard ratio (HR) 0.438; 95% CI 0.303-0.633] and with reduced risk of death (HR 0.566; 95% CI 0.368-0.870) by multivariate analysis. CONCLUSION: The results support a role for BiotHER testing in better tailoring trastuzumab-based treatments in patients with advanced HER2-amplified breast cancers.

Non-invasive (intracapsular) carcinoma ex pleomorphic adenoma: recognition of focal carcinoma by HER-2/neu and MIB1 immunohistochemistry.

AIMS: Non-invasive carcinoma ex pleomorphic adenoma is defined as a carcinoma arising within the boundaries of a pleomorphic adenoma (PA), but which fails to display invasion beyond the capsule of host PA. Alternative names are intracapsular, in situ, or focal carcinoma. The true nature of non-invasive carcinoma ex-PA is still controversial; for example, it is not clear whether it represents early but genuine carcinomatous changes with the genetic make-up of malignant cells, or simply cytological, possibly metaplastic or 'bizarre' changes in PA. Strong overexpression and amplification of HER-2/neu protein has recently been demonstrated in invasive carcinoma ex-PA. In addition, data from breast cancer studies suggest that amplification of HER-2/neu and overexpression of its gene product is mainly involved in the initiation of breast oncogenesis. We sought to establish whether this method could help to demonstrate that what is described as non-invasive carcinoma ex-PA is really a genuine malignancy, albeit in an early phase. METHODS AND RESULTS: Eleven cases of non-invasive carcinoma (in situ) ex-PA were studied for HER-2/neu status using immunohistochemistry and fluorescent in-situ hybridization (FISH). Cells of focal non-invasive carcinoma ex-PA were strongly positive for HER-2/neu protein, while the cells of the maternal PA were always negative. Two cases of low-grade non-invasive myoepithelial carcinoma ex-PA were negative. In four cases out of a total of six tumours studied by FISH, we detected amplification of HER-2/neu gene signals in tumour cells of focal, non-invasive, carcinoma. CONCLUSIONS: The current data suggest that non-invasive carcinoma ex PA is a genuine carcinoma within a PA. However, the presence of cyto-nuclear atypia is not sufficient to make a definite diagnosis of malignant change, which requires a combination of morphology and immunohistochemistry.

Cystic hypersecretory carcinoma: rare and poorly recognized variant of intraductal carcinoma of the breast. Report of five cases.

AIMS: To report five cases of a rare variant of intraductal carcinoma of the breast, so-called cystic hypersecretory carcinoma. The clinical and pathological characteristics of the lesion are described, along with a review of the literature. METHODS AND RESULTS: The patients were females aged between 53 and 78 years (average 66.8 years). The size of the lesions ranged between 70 and 80 mm in largest dimension. In two cases, the development of high-grade invasive ductal carcinoma was observed; in one additional case there was recurrence of high-grade in-situ carcinoma after 3 years. This emphasizes the importance of correct diagnosis of this potentially aggressive lesion. Strong over-expression of HER-2/neu protein was observed in three cases, including the two with an invasive component. Protein p53 was variably positive in all cases. Steroid receptor immunohistochemistry yielded variable results with only one case being positive for both oestrogen and progesterone receptors. Interestingly, in most cases (4/5) staining for androgen receptors was observed. CONCLUSIONS: Cystic hypersecretory ductal carcinoma of the breast is a rare distinctive variant of ductal carcinoma in situ. It has the potential for invasive growth and the development of metastases.

Expression of HER-2/neu gene and protein in salivary duct carcinomas of parotid gland as revealed by fluorescence in-situ hybridization and immunohistochemistry.

AIMS: Salivary duct carcinoma is a highly malignant salivary gland tumour with aggressive clinical behaviour, characterized by histological resemblance to invasive ductal carcinoma of the breast. Amplification of HER-2/neu oncogene and over-expression of its gene product have both prognostic and therapeutic implications in breast cancer. Recent report on salivary duct carcinomas for HER-2/neu using immunohistochemistry (IHC) has shown over-expression in most cases. However, correlation between IHC and molecular genetic analysis of HER-2/neu in salivary duct carcinoma has not yet been performed. METHODS AND RESULTS: We have now evaluated 11 cases of salivary duct carcinomas for HER-2/neu status using IHC and fluorescent in-situ hybridization (FISH). To our knowledge, this is the first molecular genetic analysis of HER-2/neu in salivary duct carcinoma. CONCLUSIONS: In immunohistochemistry, over-expression of HER-2/neu protein was identified as distinct membrane staining in most carcinoma cells in all our salivary duct carcinoma cases, while only four cases revealed an amplification of HER-2/neu gene by means of FISH analysis. Both amplified and non-amplified salivary duct carcinomas with strong immunohistochemical staining for HER-2/neu protein were associated with poor clinical outcome for the patients. Apparently, HER-2/neu protein over-expression could also be controlled by mechanisms other than gene amplification. In the group of salivary gland tumours other than salivary duct carcinoma, strong over-expression was detected only in three cases of carcinoma ex pleomorphic adenoma. Thus, over-expression of HER-2/neu protein is also a useful marker of malignant transformation in pleomorphic adenomas.

Risk factors for recurrence and metastasis after breast-conserving therapy for ductal carcinoma-in-situ: analysis of European Organization for Research and Treatment of Cancer Trial 10853.

PURPOSE: In view of the increasing number of patients treated with breast-conserving treatment (BCT) for ductal carcinoma-in-situ (DCIS), risk factors for recurrence and metastasis should be identified. PATIENTS AND METHODS: Clinical and pathologic characteristics from patients with DCIS in the European Organization for Research and Treatment of Cancer trial 10853 (excision with or without radiotherapy) were related to the risk of recurrence. Pathologic features were derived from a central review of 863 of the 1,010 randomized cases (85%). The median follow-up was 5.4 years. RESULTS: Factors associated with an increased risk of local recurrence in the multivariate analysis were young age (< or = 40 years) (hazard ratio, 2.14; P =.02), symptomatic detection of DCIS (hazard ratio, 1.80; P =.008), growth pattern (solid and cribriform) (hazard ratios, 2.67 and 2.69, respectively; P =.012), involved margins (hazard ratio, 2.07; P =.0008), and treatment by local excision alone (hazard ratio, 1.74; P =.009). The risk of invasive recurrence was not related to the histologic type of DCIS (P =.63), but the risk of distant metastasis was significantly higher in poorly differentiated DCIS compared with well-differentiated DCIS (hazard ratio, 6.57; P =.01). CONCLUSION: Patients with poorly differentiated DCIS have a high risk of distant metastasis after invasive local recurrence. Margin status is the most important factor in the success of BCT for DCIS; additionally, young age and symptomatic detection of DCIS have negative prognostic value.

Metaplastic (infarcted) Warthin's tumour of the parotid gland: a possible consequence of fine needle aspiration biopsy.

AIMS: The metaplastic (or infarcted) variant of Warthin's tumour is characterized by replacement of much of the original oncocytic epithelium by metaplastic squamous cells, along with areas of extensive necrosis, fibrosis and inflammatory change. The pathogenesis is unknown, but it is most likely to be vascular in origin. An association with a previous fine needle aspiration (FNA) has been suggested, and this is explored further. METHODS AND RESULTS: Nine metaplastic Warthin's tumours were collected from several centres: all arose in the parotid gland, and all showed the characteristic histological features. Eight had previously undergone FNA some 1-4 months before surgery; the other case had had an incisional biopsy. CONCLUSIONS: It is important to recognize metaplastic Warthin's tumour, because the differential diagnoses of this benign neoplasm include mucoepidermoid and squamous carcinoma, both primary and metastatic. The tumours in this study followed FNA or biopsy, and we believe this association is unlikely to be coincidental. Although many metaplastic Warthin's tumours clearly arise spontaneously, we conclude that the balance of probabilities favours the view that FNA is capable of causing metaplastic change in a Warthin's tumour, and may have done so in these cases. If so, this previously unusual subtype will become increasingly common, as FNA becomes more widely used (and its value appreciated) in the investigation of patients with a mass in the neck.