Masako Otani

Low-grade renal cell carcinoma arising from the lower nephron: a case report with immunohistochemical, histochemical and ultrastructural studies.

Most renal cell carcinomas (RCC) are composed of clear cells with sinusoid‐like vasculatures and originate from the proximal tubule. On the other hand, collecting duct carcinoma (CDC) and chromophobe RCC are thought to originate from the lower nephron. In the present study, we present a case of unusual RCC. The patient was a 68‐year‐old Japanese woman who had developed general fatigue with hematuria. Computed tomography revealed a left renal tumor suggesting sarcoma. The resected tumor was located in the renal parenchyma, measuring 12 × 10 × 8 cm in size. Histologically, the tumor consisted principally of cuboidal cells forming parallel or radiating arrays, continuous with the spindle‐shaped cells. Most parts of the tumor showed hemorrhagic necrosis. Immunohistochemically, tumor cells were positive for high molecular weight cytokeratins, vinculin, vimentin, CD15 and epithelial membrane antigen, and showed affinities with some kinds of lectins. N‐ and E‐cadherins and β‐catenin were diffusely positive in tumor cells. Nuclear positivity for Ki‐67 and p53 protein were approximately 2.0 and 1.7%, respectively. Considering its morphological and histochemical natures, this tumor is considered to have originated from the lower nephron, which is unique for a tumor of low‐grade malignancy.

Membranous glomerulonephritis with nephrotic syndrome associated with chronic lymphocytic leukemia.

A 66-year-old woman was admitted to our hospital for evaluation of edema of the extremities. Laboratory findings suggested that she had nephrotic syndrome and chronic lymphocytic leukemia (CLL). Renal biopsy (with PAM staining) showed a spike formation in the capillary wall. Immunofluorescent staining revealed deposition of immunoglobulin G (IgG) and the third component of complement in the glomerular basement membrane. Electron microscopy showed fibrillary deposits in the subepithelium. These findings indicated membranous glomerulonephritis (MGN). In addition, focal segmental sclerosis and interstitial lymphocytic infiltration were observed in the renal biopsy specimen. In CLL patients nephrotic syndrome occurs rarely. Even if the complication occurs, MGN is not frequent. Both diseases are suspected to occur in association with each other, and immunologic abnormality contributes to their coexistence. Although administration of prednisolone and endoxan improved leukocytosis, proteinuria was not sufficiently improved with combination therapy.

Nephrotic syndrome caused by protein thrombi in glomerulocapillary lumen in Waldenström's macroglobulinaemia

Waldenströms macroglobulinaemia (WM) is described as a disorder of plasmacytoid lymphocytes. The renal complications of WM are less common and severe than those of multiple myeloma. We present a case of WM complicated by nephrotic syndrome. A biopsy specimen of the kidney revealed the intraglomerular thrombi of immunoglobulin M paraprotein. Corticosteroid pulse therapy and plasmapheresis were effective in improving proteinuria and reducing protein thrombi. The nephrotic syndrome caused by protein thrombi in WM may be reversible, at least in its early stage.

Mucinous tubular and spindle cell carcinoma of the kidney: Report of a case with imprint cytologic features.

BACKGROUND Mucinous tubular and spindle cell carcinoma of the kidney is a newly established subtype in the World Health Organization classification. The tumor has a good prognosis, and its diagnosis is clinically important. However, there are no reports of its cytologic features. Here we report the cytologic findings of this rare tumor. CASE A 68-year-old female had left-sided abdominal pain, fatigue and hematuria. A large mass in the left kidney was removed. Histologically, the tumor was compatible with mucinous tubular and spindle cell carcinoma. Imprint cytologic examination revealed a large amount of tumor cells arranged in tubular, sheetlike and spindle structures. Some tumor cells showed clear cytoplasm. Nuclear atypia was mild, with occasional distinctive nucleoli. CONCLUSION The cytologic features of mucinous tubular and spindle cell carcinoma have a varied appearance. It should be included in the differential diagnosis to avoid overtreatment.

Scratch Cytologic Findings on Surgically Resected Solitary Fibrous Tumors of the Pleura

OBJECTIVE To ascertain the cytologic characteristics of solitary fibrous tumors of the pleura (SFTPs) on smear preparations. STUDY DESIGN Fine needle aspiration cytology (FNAC) was initially attempted preoperatively in five cases, but the specimens were inappropriate for interpretation because only a few tumor cells were obtained. Therefore, scratch smears made at the time of operation were used. Papanicolaou and immunocytochemical staining was performed in all 10 cases, 2 of which were malignant. RESULTS As expected, cellular tumors yielded more cells. The cytologic appearance was variable, showing spindle/bipolar, dendritic/stellate and intermediate cells. Atypical cells reminiscent of sarcoma were also present in cellular, benign tumors. Highly atypical epithelioid cells were obtained in two malignant cases. Immunocytochemically, the tumor cells were positive for CD34 and vimentin and negative for cytokeratin, regardless of histologic differences and cell shape. CONCLUSION It seems difficult to diagnose SFTPs with certainty by FNAC, partly because the cell morphology of SFTPs resembles a wide variety of heterogeneous groups of spindle cell tumors and partly because only a few tumor cells were available in the FNAC specimens in the present study. However, a cytologic diagnosis of SFTP is possible if cytologic preparations yield CD34-positive cells with spindle/bipolar or dendritic/stellate morphology.

Cytologic Features of Pleural Effusion in Apocrine Sweat Gland Carcinoma A Case Report

BACKGROUND Carcinoma arising in the apocrine sweat glands is very rare, and there are few reports of the cytologic features. We encountered a case of metastatic apocrine carcinoma in a pleural effusion. CASE A 46-year-old male had a dark reddish nodule in the right axillary region that was diagnosed as apocrine carcinoma of skin appendage origin. Three years after wide resection and chemotherapy, widespread metastases developed with a massive pleural effusion. Needle aspiration fluid cytology contained clusters of adenocarcinoma. Some tumor cells had abundant cytoplasm or periodic acid-Schiff-positive, coarse granules. Decapitation secretion was occasionally found on the cell surface. Immunohistochemically, the tumor cells were often positive for BRST-2 and BRST-3. CONCLUSION Cytologic features of metastatic apocrine sweat gland carcinoma show some characteristics of adenocarcinoma. Moreover, its definitive diagnosis in a pleural effusion can be made because of retaining the characteristics of apocrine sweat gland.

Imprint Cytologic Features of Intracytoplasmic Lumina in Ependymoma

BACKGROUND Intracytoplasmic lumina have been recently recognized as a characteristic histologic feature of ependymoma. However, the cytologic diagnostic usefulness has not been discussed. We encountered two imprint cytology cases of spinal cord ependymomas in which there were intracytoplasmic lumina in the tumor cells. CASES Two women had spinal cord tumors on magnetic resonance imaging. Imprint cytology study was carried out on the resected tumors. The cytologic specimen of the first case, aged 52, showed tumor clusters consisting of elongated epithelioid cells, a few of which also had intracytoplasmic lumina. Histologically, tumor cells formed ependymal rosettes and pseudoperivascular rosettes. There were a few tumor cells with intracytoplasmic lumina. The cytologic specimen of the second patient, aged 37, had scattered and isolated tumor cells with intracytoplasmic lumina resembling signet-ring cells and paired tumor cells forming small, glandlike structures. Histologically, the tumor was composed mainly of signet-ring-like cells containing intracytoplasmic lumina. CONCLUSION Intracytoplasmic lumina were observed in the imprint cytologic specimens of spinal cord ependymoma. The diagnosis of ependymomas can be made cytologically when intracytoplasmic lumina are found since no other primary neuroepithelial tumors of the central nervous system possess such a characteristic feature.

A case of intrarenal benign cystic teratoma.

A 6 year-old boy was diagnosed with infected renal cysts that were removed in pieces. Cytological examination of purulent fluid from the cysts during surgery contained a few isolated keratinizing aquamous cells and hair shafts with inflammatory background. Intrarenal cystic teratoma is very rare. Differential diagnosis of intrarenal cysts is paramount, especially in children, to ensure the correct choice of therapy. In our case, we found cytologic examination duning surgery to be useful in dianosis.