An ultrasonography-cytology protocol for the diagnostic management of regional nodes in a subset of patients with Merkel cell carcinoma of the skin.

BACKGROUND: The status of regional lymph nodes (LNs) is one of the most consistent predictors of survival in Merkel cell carcinoma (MCC). In cases of clinically localized disease, current practice involves sentinel lymph node (SLN) assessment. OBJECTIVES: To propose ultrasonography (US) followed by fine needle aspiration cytology (FNAC) and immunohistochemistry as a useful diagnostic tool in the pre-surgical management of patients with MCC. METHODS: US of LNs was performed in 75 patients with MCC (22 with stage III tumours; 53 with stage I-II). In patients with US suspected disease, US coupled with FNAC of the LN was performed. Smears were examined by routine cytological staining supplemented with immunohistochemical staining for cytokeratin 20. All patients underwent surgical removal of regional LNs. RESULTS: In all 22 patients with stage III tumours, US was indicative of tumour deposits and FNAC confirmed metastases to LNs. In 11 of 53 patients with localized MCC without clinical evidence of nodal disease, US revealed enlarged, equivocal nodes where FNAC was performed. Ten LNs were cytologically positive for metastases, and one was negative. Upon histological examination, the FNAC-negative case showed a metastasis 5 mm in diameter. In all the other 42 cases with no clinical or US evidence of LN involvement, only SLN biopsy was performed and in six cases small metastatic foci were detected. Ultimately, of the 53 stage I-II MCC, 17 had positive LN involvement. In 10 cases (59%) metastases were detected by FNAC, and in seven cases, were detected by SLN biopsy. CONCLUSIONS: In a selected subset (∼20%) of patients with MCC with clinically localized disease, US followed by FNAC in the suspect LN is a valid alternative to the classical protocol of SLN histological examination.

Duct carcinoma in situ of the breast: an overview.

DCIS of the breast is a lesion that was uncommon in the past (1% of the breast nodules) and now very frequent, representing not less than 20% of the mammographic lesions seen in any mammographic screening programme. This is consequent to the fact that mammography is more sensitive than palpatory clinical examination which was the diagnostic procedure offered 25 years ago.

Is acinic cell carcinoma a variant of secretory carcinoma? A FISH study using ETV6'split apart' probes.

AIMS: Acinic cell carcinomas (ACCs) and secretory carcinomas (SCs) of the breast are rare, low-grade malignancies that preferentially affect young female patients. Owing to the morphological and immunohistochemical similarities between these lesions, they have been proposed to be two morphological variants of the same entity. It has been demonstrated that SCs of the breast consistently harbour the t(12;15)ETV6-NTRK3 translocation. The aim was to determine whether ACCs also harbour ETV6 gene rearrangements and are thus variants of SCs. METHODS AND RESULTS: Using the ETV6 fluorescence in situ hybridization DNA Probe Split Signal (Dako), the presence of ETV6 rearrangements in three SCs and six ACCs was investigated. Cases were considered as harbouring an ETV6 gene rearrangement if >10% of nuclei displayed 'split apart signals' (i.e. red and green signals were separated by a distance greater than the size of two hybridization signals). Whereas the three SCs displayed ETV6 split apart signals in >10% of the neoplastic cells, no ACC showed any definite evidence of ETV6 gene rearrangement. CONCLUSIONS: Based on the lack of ETV6 rearrangements in ACCs, our results strongly support the concept that SCs and ACCs are distinct entities and should be recorded separately in breast cancer taxonomy schemes.

The fast-track biopsy (FTB): description of a rapid histology and immunohistochemistry method for evaluation of preoperative breast core biopsies.

Thirty-six core breast biopsies from 32 patients were paraffin embedded by use of an automated microwave processor. In addition, a quick immunohistochemical method was used in selected cases. The quality of the hematoxylin and eosin (H&E) slides was very satisfactory, as were also the immunohistochemical stains for ER, PR, and Ki67 when compared to those obtained with the use of a conventional automated immunostainer. The time required to process the tissue to the final H&E stage averaged 2 hours 52 minutes, and the immunohistochemical method required 90 to 100 minutes. This procedure, which we named "fast-track biopsy'' (FTB), is quick enough to be competitive with FNAC (fine-needle aspiration biopsy) in terms of turnaround-times. The superiority of core biopsy over FNA in terms of the morphologic information provided is widely acknowledged, the only major argument currently mentioned in favor of FNAC being the shorter duration of the procedure. With the advent of FTB, it would appear that even this last remaining advantage has been erased.

High-metastatic clones selected in vitro from a recent spontaneous BALB/c mammary adenocarcinoma cell line.

The metastatic TS/A line has been recently derived from a spontaneous BALB/c mammary tumor. When TS/A cells were cultured in 0.33 per cent agar, two morphologically distinct types of colonies were observed from which two sets of clones were obtained. E clones were derived from small, transparent colonies, whereas F clones were from large, thick, actively growing colonies. All the clones were tumorigenic in syngeneic BALB/c females. However, E clones showed higher ability than F clones to metastasize spontaneously to the lung. Comparison between E and F clones shows that the high level of spontaneous metastasization to the lung is associated with epithelial-like in vitro growth pattern, spontaneous dome formation and growth pattern in 0.33 per cent agar cultures. The ability to give rise to lung colonies following intravenous inoculation is not a predictive parameter for the spontaneous metastatic potential.

Reproducibility of histological diagnosis of breast lesions: results of a panel in Italy.

Sixteen pathologists independently examined and classified a series of 81 breast lesions selected from the files of several Italian Pathology Departments in the context of a national task force on breast cancer (FONCAM). A four category classification system was used for analysis; according to the majority diagnosis (MD), simply defined as the most frequently reported in the panel, the series included 37 benign lesions without atypia (45.7%), nine atypical hyperplasias (11.1%), 18 in situ (22.2%) and 17 invasive carcinomas (21.0%). Concordance, estimated for all possible pair-wise comparisons between pathologists, was good (mean kappa value: 0.59). A comparison between the diagnoses of each pathologist and the panel majority diagnosis was also made. Overall, a global kappa value of 0.72 was found (range 0.57-0.85), with category-specific values being excellent for invasive carcinoma (0.89) and benign lesions without atypia (0.77), relatively good for in situ carcinoma (0.69) but poor for atypical hyperplasia (0.38). These results confirm that quality assurance procedures are particularly indicated for large screening programmes for breast cancer, and suggest that for atypical lesions strict diagnostic criteria should be adopted.

Causes of inconsistency in diagnosing and classifying intraductal proliferations of the breast. European Commission Working Group on Breast Screening Pathology.

It is now widely recognised that classifying ductal carcinoma in situ (DCIS) of the breast and diagnosing atypical ductal hyperplasia are associated with significant interobserver variation. Two possible reasons for this inconsistency are differences in the interpretation of specified histological features and field selection where morphology is heterogeneous. In order to investigate the relative contribution of these two factors to inconsistent interpretation of intraductal proliferations, histological sections of 32 lesions were sent to 23 European pathologists followed 3 years later by images of small parts of these sections. Kappa statistics for diagnosing hyperplasia of usual type, atypical ductal hyperplasia and ductal carcinoma in situ were 0.54, 0.35 and 0.78 for sections and 0.47, 0.29 and 0.78 for images, respectively, showing that most of the inconsistency is due to differences in morphological interpretation. Improvements can thus be expected only if diagnostic criteria or methodology are changed. In contrast, kappa for classifying DCIS by growth pattern was very low at 0.23 for sections and better at 0.47 for images, reflecting the widely recognised variation in the growth pattern of DCIS. Higher kappa statistics were obtained when any mention of an individual growth pattern was included in that category, thus allowing multiple categories per case; but kappa was still higher for images than sections. Classifying DCIS by nuclear grade gave kappa values of 0.36 for sections and 0.49 for images, indicating that intralesional heterogeneity has hitherto been underestimated as a cause of inconsistency in classifying DCIS by this method. More rigorous assessment of the proportions of the different nuclear grades present could lead to an improvement in consistency.

Pathological work-up of sentinel lymph nodes in breast cancer. Review of current data to be considered for the formulation of guidelines.

Controversies and inconsistencies regarding the pathological work-up of sentinel lymph nodes (SNs) led the European Working Group for Breast Screening Pathology (EWGBSP) to review published data and current evidence that can promote the formulation of European guidelines for the pathological work-up of SNs. After an evaluation of the accuracy of SN biopsy as a staging procedure, the yields of different sectioning methods and the immunohistochemical detection of metastatic cells are reviewed. Currently published data do not allow the significance of micrometastases or isolated tumour cells to be established, but it is suggested that approximately 18% of the cases may be associated with further nodal (non-SN) metastases, i.e. approximately 2% of all patients initially staged by SN biopsy. The methods for the intraoperative and molecular assessment of SNs are also surveyed.

Primary oat cell carcinoma of the kidney.

A malignant renal neoplasm with all the morphologic attributes of oat cell (small cell, neuroendocrine) carcinoma is presented. It metastasized widely to regional lymph nodes and resulted in the death of the patient. Ultrastructurally, the tumor contained dense-core endocrine-type secretory granules. It had a cell component which was argyrophilic and which gave a positive immunocytochemical reaction for calcitonin. To the best of our knowledge, this is the first documentation of this tumor type in the kidney.

Immunohistochemical localization of myoglobin in nonmuscular cells.

Myoglobin has been detected by the immunoperoxidase technique in the cytoplasm of nonmuscular cells present in malignant tumors infiltrating skeletal muscle. The positive cells were reactive histiocytes in one case, and malignant cells (breast carcinoma, malignant melanoma, and malignant lymphoma) in the others. These findings indicate the need to exercise caution in the interpretation of myoglobin stain for the diagnosis of rhabdomyosarcoma under these circumstances.

Immunohistochemical analysis of benign and malignant papillary lesions of the breast.

The histocytological diagnostic criteria and recently developed immunohistochemical procedures selective for either the epithelial or the myoepithelial mammary cells have been tested in a series of 60 cases of papillary lesions of the breast. These included 15 benign solitary intraductal papillomas, 41 papillary carcinomas (29 pure and 12 associated with other types of in situ or invasive ductal carcinoma), and four cases of "suspected" papillary carcinomas. Markers for epithelial cells (EMA) and for apocrine metaplasia (GCDFP-15) did not permit a distinction between benign and malignant papillary lesions; however, immunocytochemical staining for CEA using monoclonal antibodies, and for actin (a marker of the myoepithelial cells) was discriminative in this respect. Benign papillomas have a basal layer of actin-rich myoepithelial cells; the cytoplasm of the epithelial cells is CEA negative. Papillary carcinomas lack the myoepithelial layer, except in areas where multiple papillomas are present, associated with ductal or papillary cancer. CEA was detected in 85% of carcinomas. Two of the cases of "suspected carcinoma" lacked myoepithelial cells and were interpreted as carcinomas. It is concluded that the immunocytochemical methods for cell markers can offer valuable data in the study and diagnosis of papillary lesions of the breast; it is difficult, however, to be categorical in borderline cases since in our experience, the behavior of the malignant papillary lesions of the breast is usually favorable. Residual foci of multiple intraductal papillomas were found in seven cases of papillary carcinoma, supporting the pre-neoplastic potential of this condition.

Neuroendocrine carcinoma within lymph nodes in the absence of a primary tumor, with special reference to Merkel cell carcinoma.

We report eight cases of neuroendocrine carcinomas found within inguinal (five cases), axillary (two cases), and submandibular (one case) lymph nodes. The patients underwent extensive investigations, but no primary tumor was found in any case. Although the existence of an occult or regressed primary cannot be ruled out, the possibility of a lymph node origin should be considered on the basis of epithelial inclusions or anomalous carcinomatous differentiation of stem cells of the lymphoreticular system.

Immunocytochemistry of rhabdomyosarcoma. The use of four different markers.

Fast myosin and slow myosin are specific markers of skeletal muscle, in addition to myoglobin. This study of 15 specimens of rhabdomyosarcomas from 13 patients using specific antisera for the three markers as well as for desmin led to positive findings in all cases with at least one antiserum. Desmin was present in all cases; fast myosin and myoglobin were present in 10 cases each. Slow myosin was present in six cases. It appears that the combination of several markers is helpful in differentiating rhabdomyosarcomas from other tumors. The markers considered were generally more abundant in neoplastic elements with large amounts of cytoplasm. This finding suggests that the larger cells of rhabdomyosarcomas are more differentiated than smaller rhabdomyoblasts, which were often negative with some of the antisera used.

Keratin-positive epithelioid angiosarcoma of thyroid. A report of four cases.

We present four cases of a malignant thyroid tumor showing morphologic, immunocytochemical, and ultrastructural features of endothelial cell differentiation. The tumor cells had epithelioid features and displayed strong immunoreactivity for keratin. There was no evidence of follicular or C-cell differentiation in any instance. We interpreted these cases as keratin-positive epithelioid angiosarcomas. The findings presented here support the existence of primary malignant vascular tumors in the thyroid even in the presence of keratin positivity, a marker traditionally regarded as indicative of epithelial differentiation.

Primary malignant lymphoma of sciatic nerve. Report of a case.

A 72-year-old man with a 2-year history of motor-sensory neuropathy of the right foot was found to have a lymphoma involving a 50-cm length of the sciatic nerve. This occurred in the absence of any other evidence of disease by detailed clinical staging. The lymphoma was of large follicular center-cell type. The cells strongly expressed a B-cell marker detected by the 4KB5 monoclonal antibody and selectively infiltrated the nerve bundles, dissociating preexisting myelin-producing Schwann cells and axons. This is the second report of similar localization. Primary selective involvement of a nerve is a rare mechanism of peripheral neuropathy in lymphoproliferative disorders, to be added to systemic dissemination of lymphomas and leukemias, direct spread of an adjacent tumor, and immunologically mediated disease.

Sarcomatoid carcinoma of the anorectal junction with neuroendocrine and rhabdomyoblastic features.

A case of sarcomatoid carcinoma of the anorectal junction in a 71-year-old woman showing neuroendocrine and rhabdomyoblastic features is described. The tumor was diffusely infiltrative and metastases to regional lymph nodes were found at laparotomy. The patient died 6 months after surgery with widespread metastases.

Myoblastomatoid (histiocytoid) carcinoma of the breast. A type of apocrine carcinoma.

Thirteen carcinomas of the breast having in common neoplastic cells with granular to foamy cytoplasm are described. These cells exhibit apocrine differentiation as demonstrated by immunocytochemical and in situ hybridization studies. These tumors can be easily misinterpreted as either fibrohistiocytic or myoblastomatoid (granular cell) tumors. Therefore, the designation of myoblastomatoid (histiocytoid) invasive carcinomas seems the most appropriate for this specific group of apocrine carcinomas.

Oncocytic carcinoma (malignant oncocytoma) of the breast.

Three cases of oncocytic carcinoma of the breast observed in two women and one man are reported. One tumor was in situ and two were invasive. All three tumors were composed mostly of cells with "low-grade" nuclei and abundant granular eosinophilic cytoplasm. More than 70% of the neoplastic population in each case was immunoreactive with an antimitochondrion antibody. The presence of numerous mitochondria also was demonstrated at the ultrastructural level. Apocrine cells and oncocytes share similar morphologic features at the hematoxylin-eosin level; however, there are some differences that allow a confident distinction between these two cell types. Mitochondria in apocrine cells usually are in a perinuclear location and are not so numerous and diffusely dispersed as in oncocytes. In addition, apocrine cells display features of active secretory elements: prominent microvilli, well-developed Golgi complex, and electron dense secretory granules polarized toward the luminal pole; all these features were lacking in the three cases described. The cells constituting the present cases were not positive at the immunohistochemical and molecular levels for GCDFP-15/PIP mRNA, which are typical markers of apocrine differentiation. We suspect that mammary oncocytoma is a more common tumor than the meager number of reported cases suggests.

Small cell neuroendocrine carcinoma with skeletal muscle differentiation: report of three cases.

Three cases of neuroendocrine carcinoma showing skeletal muscle differentiation are presented. The tumors were located in the skin and subcutaneous tissue, the urinary bladder, and the nasal cavity respectively, and were composed by two cell types admixed intimately with each other. One cell type had features identical to those seen in conventional small cell neuroendocrine carcinoma, including scanty cytoplasm, round nuclei with fine granular chromatin, immunohistochemical reactivity for neuron-specific enolase, chromogranin and cytokeratins, and electron-dense granules on ultrastructural examination. The second cell type was either plasmacytoid or elongated and straplike, with abundant eosinophilic cytoplasm and irregular nuclei with prominent nucleoli. These cells showed immunohistochemical positivity for desmin, sarcomeric actin, myoglobin, and myogenin. They also exhibited ultrastructural evidence of rhabdomyoblastic differentiation in the form of contractile filaments with abortive Z-band formation. An origin from a cell capable of dual differentiation toward neuroendocrine and rhabdomyoblastic elements is postulated for these tumors.

Acantholytic variant of squamous-cell carcinoma of the breast.

Three cases of acantholytic squamous-cell carcinoma of the breast are reported. They all had histological features resembling those of angiosarcoma or adenocarcinoma. They were not angiosarcoma, since in all three cases areas of squamous differentiation were present; in addition, the neoplastic cells were negative when stained for factor VIII, but were positive with anti-epidermal keratin. The glandular pattern exhibited, especially in Case 2, was difficult to differentiate from that of an ordinary carcinoma. However, the presence of dyskeratotic cells within the lumina, and the absence of alcian blue/periodic acid-Schiff positive material, and epithelial membrane antigen staining, were evidence against the diagnosis of adenocarcinoma. The patients died 5, 6, and 16 months after the diagnosis. Tumors with these histological features may have a very aggressive clinical course.