Transitional cell carcinoma of the bladder mimicking lobular carcinoma of the breast: a discohesive variant of urothelial carcinoma.

AIMS: To describe a series of 10 cases of transitional cell carcinoma which show morphological features which mimic lobular carcinoma of the breast and diffuse carcinoma of the stomach. METHODS AND RESULTS: Ten cases were identified from the files at Southampton University Hospitals NHS Trust and from the authors' consultation files. Immunostains were performed and clinical information was obtained. Eight of the patients were male and two female. Ages ranged from 52 to 77 years at presentation. All of the tumours showed areas where the tumour was composed of uniform cells with a discohesive single-cell, diffusely invasive growth pattern. In areas the tumour cells were arranged in linear single-cell files and in separate areas solid sheets of discohesive cells. In all of the cases some tumour cells showed prominent intracytoplasmic vacuoles. In addition to this pattern, four cases showed typical transitional cell carcinoma or carcinoma in situ. The majority of the tumours expressed cytokeratin 20 but not oestrogen receptors. CONCLUSION: This study highlights a pattern of diffusely invasive transitional cell carcinoma not previously described and one which is important to recognize in order to avoid misdiagnosis of metastatic lobular carcinoma of the breast, especially in small biopsies.

Immunohistochemical phenotype of malignant mesothelioma: predictive value of CA125 and HBME-1 expression.

Histological diagnosis of malignant mesothelioma and differentiation from adenocarcinoma is often difficult. Definitive pathological confirmation of malignant mesothelioma requires demonstration of an appropriate immunohistochemical phenotype. Selection of an optimum panel of immunohistochemical antibodies for the reliable identification of malignant mesothelioma is hindered by the absence of a specific immunohistochemical label for mesothelioma cells. Recently, we have found that the ovarian carcinoma cell antibody CA125 labels malignant mesothelioma cells, and the antibody HBME-1 has been developed as a sensitive mesothelial cell marker. We have compared the immunohistochemical staining patterns achieved with CA125 and HBME-1 to those obtained using a panel of eight further antibodies in 17 malignant mesotheliomas and 14 primary and secondary adenocarcinomas within lung and pleura. CA125 labelled malignant mesothelioma cells in 15 of 17 cases (88%), and adenocarcinoma cells in seven of 14 cases (50%). HBME-1 labelled mesothelioma cells in all 17 cases (100%) but also labelled adenocarcinoma cells in 10 of 14 cases (71%). BerEP4 positively labelled one malignant mesothelioma but was negative in the remaining 16 cases and positively labelled nine of 14 adenocarcinomas (64%). Monoclonal anti-CEA, AUA-1, CA19.9 and LeuM1 labelled no malignant mesotheliomas and were positive in 10 (71%), nine (64%), eight (57%) and six (43%) of 14 cases of adenocarcinoma, respectively. Diastase-PAS staining detected neutral mucin in none of the malignant mesotheliomas but in 10 (71%) of the 14 adenocarcinomas. We conclude that CA125 and HBME-1 do not label mesothelial cells with sufficient specificity to be useful for differentiating malignant mesothelioma from adenocarcinoma, although negative staining with HBME-1 makes a diagnosis of malignant mesothelioma unlikely. As there remains an absence of a specific positive mesothelial cell marker this distinction is still most reliably made using a panel of antibodies including at least two of the following: anti-CEA, AUA-1, BerEP4, LeuM1 and CA19.9, in combination with histochemical assessment of neutral mucin production.

Primary cervical lymphoma: the role of cervical cytology.

Two cases of primary malignant lymphoma of the uterine cervix are reported. Both were confirmed by histology as high grade B cell lymphomas. In one case, the diagnosis was made on a second colposcopic biopsy after an initial cervical smear and colposcopic biopsy were negative. In the second case, dyskaryotic cells of uncertain type were identified in a cervical smear taken at colposcopy performed as part of follow up for previous cervical intraepithelial neoplasia (CIN)I. The cytologic features and differential diagnosis of this rare cervical neoplasm are discussed, with emphasis on the role of the Papanicolaou smear in the initial diagnosis of this tumour.

Investigation of specimen mislabelling in paraffin-embedded tissue using a rapid, allele-specific, PCR-based HLA class II typing method.

Mislabelling of surgical specimens can seriously affect the accuracy of histopathology reports. We describe two cases in which clinically suspected mislabelling was investigated by polymerase chain reaction (PCR)-based HLA DRB and DQB tissue typing of paraffin biopsy-derived DNA, using sequence specific primers (PCR-SSP HLA typing). In the first case, two patients underwent surgery for breast carcinoma. A subcutaneous lymph node containing metastatic carcinoma was received with the breast specimen from one patient, but was clinically considered more likely to originate from the other patient who underwent breast surgery on the same day. In the second case, histological examination of retained products of conception from a young woman revealed adenocarcinoma, but a repeat curettage specimen consisted of secretory phase endometrium. In case 1, PCR-SSP HLA typing confirmed the clinical suspicion that the subcutaneous lymph node received with tissue from one patient originated from the other patient. This result converted the first patient from lymph node positive breast carcinoma to lymph node negative disease. In case 2, there was no evidence from PCR-SSP HLA typing that the endometrial samples had originated from different patients. PCR-SSP HLA typing requires fewer steps than methods based on PCR amplification followed by oligonucleotide probing (PCR-SSOP HLA typing), and relies on the amplification of shorter sequences of DNA. Therefore, this technique can produce more rapid results than PCR-SSOP HLA typing, and is ideally suited to typing partially degraded DNA derived from formalin-fixed and paraffin-embedded tissue.

Combined goblet cell carcinoid and mucinous cystadenoma of the appendix.

Two cases of combined goblet cell carcinoid and mucinous cystadenoma occurring in the appendix are reported. The histogenesis of the goblet cell carcinoid remains one of its most controversial aspects and the occurrence of both of these relatively uncommon tumours in the same organ may lend support to the unitary stem cell hypothesis on the origin of this tumour. Alternatively, this occurrence may represent an example of the adenoma/carcinoma sequence.

Cystic carcinoma of the breast: a trap for the unwary.

Cystic breast masses are a common presentation to breast clinics. While the majority of cysts can be managed by simple aspiration, a small proportion are malignant. Histology records for a 10-year period have been examined to identify patients with cystic breast carcinomas. In all, 31 patients were identified. Of these, 18 had cystic degeneration of high-grade tumours, while 13 had intracystic papillary carcinoma. Both of these tumour types were diagnosed by a combination of cyst fluid cytology and breast imaging. The prognosis of high-grade tumours was poor, while that of intracystic papillary carcinomas was excellent. After cyst aspiration, bloodstained fluid should be sent for cytology and breast imaging arranged in all patients. Patients in whom a cyst refills within 2 week of aspiration require a careful re-evaluation. Cysts in postmenopausal women should be viewed with suspicion. Excision should be performed in patients with positive cytology or imaging.

Orange-red birefringence of gold particles in paraffin wax embedded sections: an aid to the diagnosis of chrysiasis.

Chrysiasis, the systemic deposition of gold pigment in patients on long term chrysotherapy, is identified histologically as small black granules within macrophages. Histological sections from 12 confirmed cases of chrysiasis were examined under crossed polarized light. This revealed a striking orange-red birefringence of the pigment not detected in other histologically similar deposits. This technique provides a valuable adjunct to the histological identification of gold without the need to resort to ultrastructural and analytical procedures.