Eiichiro Hirakawa

Collision tumor of cutaneous malignant melanoma and basal cell carcinoma.

An extremely rare case of a collision tumor of malignant melanoma (MM) and basal cell carcinoma (BCC) located in the temporal scalp of a 78-year-old male is reported. Microscopic examination revealed a collision tumor consisting of the nodular type, Clarks level IV MM, and a pigmented BCC. The tumor was studied by immunohistochemistry and was analyzed for point mutations of codons 12 and 61 of H-ras, K-ras and N-ras oncogenes. Tumor cells of the MM were positive for S-100 protein, HMB-45 and vimentin, but negative in the BCC. The malignant melanoma possessed an activating A to T transversion in codon 61 of N-ras gene, which is the code for leusine instead of glutamine. This is the first report of ras oncogene mutation in such a collision tumor. MM and BCC are clearly different in terms of histological, immunohistochemical and ras gene mutation analyses. These findings support the view that the association of MM and BCC in this collision tumor is a chance occurrence.

Intrathyroidal branchial cleft‐like cyst in chronic thyroiditis

An extremely rare case of intrathyroidal branchial cleft‐like cyst is reported. A 71‐year‐old man complained of a growing mass in the right lateral neck. A cystic mass in the upper lobe of the right thyroid was demonstrated by ultrasonography and computed tomography. The surgical specimen revealed a cystic mass with dense fibrous capsule, 22 × 20 × 10 mm in size. Microscopically, the cyst walls and the surrounding thyroid tissue contained severe lymphoid cell infiltration with lymphoid follicle. Squamous epithelium lined the cyst wall. Immunohistochemically, squamous epithelium was positive for keratin, cytokeratin 19, carcinoembryonic antigen, and epithelial membrane antigen, but negative for calcitonin and chromogranin A. The patient is currently well with no evidence or recurrence for 43 months.

Asymptomatic dissecting aneurysm of the coeliac artery: a variant of segmental arterial mediolysis

particularly important in wide local excision specimens where the amount of DCIS and its proximity to surgical margins may determine the need for further surgical intervention. It is also helpful in cases detected at breast screening where detailed radiological–pathological correlation provides a useful audit of the imaging findings. It is well recognized, however, that there is poor agreement amongst UK breast screening pathologists in the measurement of breast tumour size. In screening cases the pathological abnormality is usually impalpable and difficult to see on macroscopic examination, but calcification often provides a useful marker for targeted sampling after X-ray of the specimen slices. In specimens without such a radiological guide the only way to derive this figure is through extensive tissue sampling with careful block mapping and the use of composite or large blocks. Whilst this is a time-consuming process—depending on the size of the specimen—it is essential, given the clinical significance of finding DCIS at or near a resection margin and the implications for risk of recurrence in finding a high volume of surrounding DCIS. The figure derived for extent of DCIS in a plane other than that represented on the tissue slices, however, is often quite imprecise if it involves an assessment of involvement of parallel blocks. The usefulness of this approach in mastectomy specimens is less obvious. In specimens without a radiological marker, such as calcification, it is questionable whether the extent of sampling required to establish this figure with any degree of accuracy is worthwhile, given the limited relevance of the information so derived. Determining the whole tumour size to include surrounding DCIS may be of interest for audit, research and epidemiological purposes but is of limited relevance for an individual patient. DCIS often extends along major ducts towards the nipple and some protocols for examination of excision specimens emphasize the need for greater sampling in this direction. In a mastectomy, the presence of nipple involvement may provide reassurance that conservative surgery would have been inappropriate, but most conventional protocols for examination of these specimens already involve sampling this area. The need to undertake a complex time-consuming process in order to assess DCIS extending in other planes, particularly in non-screening cases, is far from clear. Pathological assessment of whole tumour size to include DCIS extending beyond the main mass of an invasive cancer in a mastectomy specimen is likely to provide a very inaccurate figure. As many of these cases are advanced breast cancers and much of the preexisting DCIS may have been ‘overgrown’ by invasive disease, the chances of finding DCIS are also much less than in a wide local excision for screen-detected malignancy. The current workforce crisis in histopathology behoves us to look carefully at work which may be potentially unnecessary or of limited clinical usefulness. We have recently reported that random sampling of breast quadrants in mastectomy specimens very rarely provides any useful information. Is attempting to determine the whole tumour size in mastectomy specimens for advanced breast cancer really an appropriate use of our time?

A case of infantile rhabdomyofibrosarcoma with immunohistochemical, electronmicroscopical, and genetic analyses

A case of infantile rhabdomyofibrosarcoma arising on the buttocks of a 15-month-old boy is reported with histological, immunohistochemical, electronmicroscopical, and cytogenetic findings. Histological examination showed a proliferation of spindle-shaped cells in a fasciculated pattern, with occasional rounded rhabdomyoblastic cells with abundant eosinophilic cytoplasm. Immunohistochemically, the tumor cells expressed desmin and MyoD1 but were only weakly positive for myoglobin. No clear rhabdomyoblastic features were observed by electronmicroscopic examination. Chromosome analysis showed a clone of 46, XY, der(2)t(2;11)(q37;q13), different from any karyotypic abnormality in the original report of this neoplasm. Loss of heterozygosity at 11p15.5, the most frequent genetic alteration in embryonal rhabdomyosarcoma, was not detected. The low degree of striated muscle differentiation and tumor localization supported the diagnosis of infantile rhabdomyofibrosarcoma rather than spindle-cell rhabdomyosarcoma in this case. The present case has been uneventful as of 25 months after surgery. The rather long recurrence-free period, which has not been reported in previous cases, may be attributable to chemotherapy-induced rhabdoid differentiation of the tumor cells.

Expression of vimentin and high-molecular-weight cytokeratin (clone 34ßE12) in differentiating reactive renal tubular cells from low-grade urothelial carcinoma cells in voided urine.

H. Ohsaki, E. Hirakawa, M. Nakamura, Y. Norimatsu, H. Kiyomoto and R. Haba

Can cytological features differentiate reactive renal tubular cells from low‐grade urothelial carcinoma cells?

H. Ohsaki, E. Hirakawa, Y. Kushida, S. Yokoshita, M. Nakamura, H. Kiyomoto and R. Haba

Composite mucinous and granulosa cell tumor of the ovary

A composite mucinous and granulosa cell tumor of the ovary in a 76‐year‐old woman is herein reported. At laparotomy this tumor proved to be a solid and cystic mass measuring 10 cm in greatest diameter. Many of the cysts were lined with a benign mucinous epithelium of the endocervical type, and solid areas contained a proliferation of granulosa cells. These two disparate components were intimately mixed. A theca cell component was also present in areas adjacent to the mucinous epithelium. The coexistence of mucinous and granulosa cell tumor is extremely rare and only four such cases have previously been reported in the literature, and the histogenesis of this tumor has not yet been elucidated. In the present case it is suggested that the granulosa cell element commenced as a reactive stromal hyperplasia in the wall of the pre‐existing mucinous neoplasm and thereafter progressed to the point of producing a tumor‐like mass or neoplastic changes.

Meningeal Hamartoma of the Scalp A Variant of Primary Cutaneous Meningioma

A case of meningeal hamartoma of the scalp is reported. A 15‐year‐old girl was admitted complaining of scalp nodules in the midline occipital region. A midline skull defect was found under the nodular lesions. Histologically, the mass had a fibrocollagenous tract extending to the dura and showed an admixture of mature adipose tissue, small ves sels, strands of fibrocollagenous tissue, and scattered foci of meningocytes. lmmunohistochemically, the menin‐gocytes were positive for vimentin. Ultrastructurally, the meningocytes had scattered desmosomes, interdigitating processes, and intermediate filaments. The patients brother also had the meningeal hamartoma of the scalp. Meningeal hamartoma as a variant of primary cutaneous meningioma is extremely rare, and this is the first report of such a case in Japan. Acta Pathol Jpn 42: 353–357, 1992.

Cytomorphologic and immunocytochemical characteristics of reactive renal tubular cells in renal glomerular disease.

OBJECTIVE To investigate the morphologic characteristics and immunocytochemical reaction to vimentin of the reactive renal tubular cells (RRTCs) in renal glomerular disease. STUDY DESIGN We prospectively evaluated the urine cytology of renal glomerular disease in 40 patients who underwent renal biopsy. The cytology and renal biopsy specimens were analyzed for vimentin immunostaining. RESULTS A total of 40 urine samples from the 40 patients were cytologically analyzed, and RRTCs were found in 25 samples (25 of 40, 62.5%). These RRTCs showed clear or vacuolated cytoplasm, intracytoplasmic pigmented granules (hemosiderin or lipofuscin) and large nuclei with round to irregular nuclear contours and prominent nucleoli. These cells were seen singly and in acinar clusters. Occasionally RRTCs were embedded in a cast (RRTC cast). Immunocytochemicalstudy revealed RRTCs to be positive for vimentin (25 of 25, 100%). CONCLUSION Frequently observed characteristic cytomorphologic features of RRTCs included RRTC cast, acinar cluster, vacuolated cytoplasm and intracytoplasmic pigmented granules. A diagnosis of RRTCs can be suggested based on these cytomorphologic features. However, a definitive diagnosis will require immunocytochemical confirmation for vimentin.

Value of computer-assisted quantitative nuclear morphometry for differentiation of reactive renal tubular cells from low-grade urothelial carcinoma.

H. Ohsaki, E. Hirakawa, K. Kagawa, M. Nakamura, H. Kiyomoto and R. Haba