Renal oncocytoma: long-term follow-up and flow cytometric DNA analysis

We report a retrospective study on the clinicopathologic features and flow cytometric DNA analysis of ten renal oncocytomas compared with a control group of ten randomly selected renal cell carcinomas. Among the oncocytoma patients, no recurrences or metastases were noted over an average follow-up of 6.7 years (range = 6 months to 16 years). Reproducible, high-quality DNA histograms were obtained on the paraffin-embedded specimens by using our modified flow cytometric procedure. One aneuploid (10%) and two hyperdiploid tumors (20%) were found in the oncocytoma group. There was no correlation between these abnormal DNA histographic patterns and survival or tumor stages. On the contrary, a good correlation was found between tumor grades and DNA ploidy in the controls. We conclude that renal oncocytoma is a clinically benign tumor, yet it may exhibit varying degrees of flow cytometric DNA abnormalities, which have no predictive value on survival and probably reflect the characteristics of oncocytes rather than its malignant potential.     

Light and electron microscopic study of the degree of differentiation of cancer of the large intestine

Two groups of human rectal tumors histologically identified as well- and poorly-differentiated carcinomas were studied by means of electron microscopy. Some tumors of the former group consisted of undifferentiated cells only, while the others comprised chiefly differentiated cells (goblet cells, enterocytes, oncocytes and/or endocrine cells). Some tumors of the latter group consisted of undifferentiated cells only or partially. The remaining tumors were formed mostly of differentiated cells with organ-specific characteristics. It is inferred that a comparison of the results of identification of the degree of tumor cell differentiation by light and electron microscopy may be inconclusive. This conclusion may provide a plausible explanation of the difference in prognosis and response to treatment of rectal tumors of similar histological patterns.     

肾嗜酸细胞瘤2例报告并文献复习

目的提高对肾嗜酸细胞瘤的认识,探讨肾嗜酸细胞瘤的治疗方法。方法报告2例肾嗜酸细胞瘤并复习国内外文献。结果本组例1术前疑诊为肾嗜酸细胞瘤,并为术中快速冰冻切片证实,行保留肾脏的腹腔镜肿瘤剜除术,术后随访2年,一般情况良好,无复发,无转移。例2术前诊为肾癌,行腹腔镜左肾根治性切除术,术后随访3年,无复发,无转移,肝、肾功能均正常。结论肾嗜酸细胞瘤的诊断要点:(1)肿瘤无明显症状,多为偶然发现,肿瘤生长缓慢,无周围浸润或远处转移,多为单发;(2)肿瘤突出于肾轮廓之外,呈外突性生长;(3)肿瘤切面呈棕褐色;(4)CT示肿块密度均匀,无出血、坏死,有完整包膜;(5)病理检查:光镜下肿瘤由单一的嗜酸细胞构成,电镜下细胞富含线粒体。一旦确诊,应尽可能行保留肾脏的手术,避免行根治性肾切除术。     

A morphological analysis of an in vitro model of cytotoxic antitumor activity

Models of adoptive immunotherapy and cytotoxicity of lymphocytes isolated from tumor tissues were studied. A microcytotoxicity model utilizing serum-free culture conditions was evaluated by light microscopy, scanning electron microscopy, and transmission electron microscopy for antitumor activity. By examining morphologically the relationship between peripheral blood mononuclear cells and tumor-infiltrating lymphocytes, it was demonstrated that the latter and macrophages had morphological features similar to the cytotoxic cells obtained in vitro from peripheral blood. When allowed sufficient time in our culture conditions, the tumor-infiltrating cytotoxic cells seem to kill the tumor cells within a few days to many months. The ultrastructural morphology of the interaction between the cytotoxic cells and the tumor cells was described as well as some proteinaceous secretory granules that seem to be transferred to the tumor cells through these interactions.     

Peripheral nerve tumor with rhabdomyosarcomatous differentiation (malignant "triton" tumor)--report of 3 cases

In this paper, 3 cases of malignant "triton" tumor are reported. By special stain, immunohistochemistry and electron microscopy, coexistence of rhabdomyoblasts and Schwann's cell elements was demonstrated. Case 1 was associated with von Recklinghausen disease; in case 3, the tumor developed within a nerve; both had background of malignant schwannoma. Case 2 was a girl with congenital giant pigmented nevus. Her tumor was composed predominantly of rhabdomyoblasts element but by immunohistochemistry, it was confirmed that her tumor also occurred within a nerve. The criteria of diagnosis, differential diagnosis and histogenesis are discussed.     

A case of primary B-cell lymphoma of the breast. Light and electron microscopy, and immunologic cell markers

A case of primary non-Hodgkin's lymphoma of the breast was studied with light and electron microscopy and for immunologic cell markers. With light microscopy, the tumor was seen to be a poorly differentiated lymphocytic lymphoma, diffuse, according to Rappaport's classification. With electron microscopy, the tumor was seen to consist of a cytologically uniform cell population. The cells were characterized by irregularly shaped nuclei with infrequent cytoplasmic projections and "microvilli-like" structures, mimicking small cleaved follicular center cells. The immunologic cell marker study showed that the cells were positive for surface IgA and HLA-DR antigen; negative for SRBC receptors, Leu 1, Leu 2a, and Leu 3a antigens. The collective evidence indicated the tumor was of B-cell origin.     

Can renal oncocytomas be distinguished from renal cell carcinoma on fine-needle aspiration specimens? A study of conventional smears in conjunction with ancillary studies.

BACKGROUND: The reliability of using fine-needle aspiration (FNA) to distinguish renal oncocytoma (RO), a benign tumor, from renal cell carcinoma (RCC), which has eosinophilic granular cytoplasm, has been questionable. However, it is clinically significant, because radical nephrectomy may be avoided in patients with RO. The authors retrospectively studied the cytologic features and ancillary study findings of RO compared with findings in RCCs with eosinophilic granular cytoplasm to evaluate the reliability of FNA-based diagnosis of RO. METHODS: The authors reviewed 19 tumors, including 11 ROs, three chromophobe RCCs (CRCCs), three granular variant RCCs (GRCCs), and two eosinophilic variant papillary RCCs (EPRCCs). Smears and cell blocks were prepared using either computed tomography-guided or ultrasound-guided FNA material. Surgical specimens were available for all tumors. Cytokeratin, vimentin, and Hale colloidal iron (HCI) stains were performed on all 19 tumors. Electron microscopy (EM) was available for six tumors. RESULTS: Although most tumors demonstrated their classic cytologic features, the specific diagnosis using conventional smears or even core biopsies was difficult in some tumors, especially ROs, due to the overlapping cytomorphology among these tumors. Cytologic material was obtained from 10 of 11 RO specimens. Of 10 ROs, 8 original FNA-based diagnoses were oncocytic neoplasm. Immunoperoxidase studies revealed that all tumors of each type were positive for cytokeratin, whereas only GRCCs and EPRCCs were positive for vimentin. The two vimentin negative neoplasms, RO and CRCC, could be distinguished by HCI stain, which showed diffuse or focal cytoplasmic positivity in CRCCs and apical/perinuclear staining (73%) or negative staining (27%) in ROs. Ultrastructurally, cytoplasm densely packed with mitochondria was characteristic for oncocytoma. CONCLUSIONS: This study demonstrated that ROs can be distinguished reliably from RCCs on the basis of cytologic morphology combined with ancillary studies, including immunostaining with cytokeratin and vimentin antibodies and HCI stain. EM provides additional information to confirm the diagnoses.     

Argyrophilic carcinoma "carcinoid tumor" of the breast: case report with electron microscopic and immunohistochemical investigations

A rare primary argyrophilic carcinoma "carcinoid tumor" of the breast in a 48-year-old woman was investigated by light and electron microscopy, and immunohistochemistry. Light microscopy showed the greater part of the tumor to have characteristic histological features of carcinoid tumor and Grimerius' stain revealed the presence of numerous argyrophilic granules in the tumor cells. Numerous neurosecretory granules and bundles of intermediate filaments were observed ultrastructurally in the cytoplasm. In addition, carcinoembryonic antigen (CEA) and neuronespecific enolase (NSE) were detected in the tumor cells using the immunoperoxidase method. From the results, it is speculated that the tumor cells have the ability to produce CEA as well as NSE in the cytoplasm. The observation of ductal spreading in parts of the tumor, and the detection of CEA, suggest the tumor cells to be derived from mammary epithelial cells.     

Pathophysiology of transitional tumor cell adherence to sites of urothelial injury in rats: mechanisms mediating intravesical recurrence due to implantation

The mechanism by which transitional tumor cells adhere to areas of urothelial injury and the means by which heparin prevents this phenomenon were studied. Scanning electron microscopy and a radiolabeled tumor cell adherence assay were used to assess the activity of heparin and a "nonglycosaminoglycan" thrombolytic agent, recombinant tissue plasminogen activator, in preventing tumor cell adherence to areas of urothelial injury. Systemically administered heparin and intravesical therapy with recombinant tissue plasminogen activator duplicated the activity of intravesical heparin. Scanning electron microscopy showed tumor cells entrapped at the injury surface in a RBC/fibrin clot, which was prevented by intravesical heparin. These data suggest that clotting cascade activation by urothelial injury is the mechanism by which particulate adherence to the urothelium occurs. Interruption of this process by local or systemic anticoagulation with heparin or shifting of the equilibrium of clot formation/lysis toward thrombolysis with recombinant tissue plasminogen activator prevents tumor cell adherence. Intravesical thrombolytic therapy may represent a new approach to recurrence prophylaxis for superficial bladder carcinoma.     

Pulmonary oncocytoma

A pulmonary tumor composed of oncocytes was removed surgically from a 53-year-old man. Diagnosis was made after ultrastructural study. Pathological significance of this rare entity is briefly discussed and the literature reviewed.     

Strumal carcinoid of the ovary: an analysis of its components.

A strumal carcinoid of the ovary was studied by light and electron microscopy. Thyroglobulin was demonstrated within the strumal element by immunofluorescence, thus establishing the identity of the thyroid tissue. The carcinoid fulfilled the light and electron microscopic criteria for a mixed insular and trabecular example of this tumor. Intermediate zones between the two tissue elements showed mixed characteristics. No amyloid was found. Immunoreactive calcitonin was demonstrated in the tumor, suggesting the presence of C-cells or medullary carcinoma of the thyroid.     

Granulocytic sarcoma with an indolent course and destructive skeletal disease. Tumor characterization with immunologic markers, electron microscopy, cytochemistry, and cytogenetic studies

A 6-year-old girl with a granulocytic sarcoma (GS) of the left maxillary sinus that followed a uniquely indolent clinical course (3.5 years) and was associated with highly destructive skeletal disease is described. The tumor cells demonstrated an unusual hematogenous "homing" preference for bone and soft tissue sites. Tumor cell characterization with immunologic markers, electron microscopy, cytochemistry, and cytogenetic studies revealed that the tumor cells expressed OKM1 and MMA (Leu-M1), but not HLA-DR, B-, or T-cell markers. The cells were nonspecific esterase- and myeloperoxidase-positive, had ultrastructural features of promyelocytes, and were clonal. The laboratory characterization of the tumor cells in this clinically unusual case of GS illustrates the utility of monoclonal antibodies, applied in conjunction with cytochemistry and ultrastructural analysis, in establishing the specific diagnosis, cell lineage, and maturational stage of this tumor.     

Lipid cell tumor of the ovary: an ultrastructural study.

An ovarian lipid cell tumor without Reinke's crystalloids in a woman with secondary amenorrhea, minimal hirsutism, and elevated 17-ketosteroid excretion was studied by light and electron microscopy. Tumor cells were found in small clumps or scattered singly within a collagenous matrix. The cytoplasm of the tumor cells contained abundant smooth endoplasmic reticula, numerous mitochondria with tubular cristae, lipid droplets, lysosomal dense bodies, and concentric membranous whorls, characteristic of steroidogenic cells. In addition, "peripheral canalicular systems" were found at the outer margins of the nests of the tumor cells. These "peripheral canalicular systems" were bordered by the cell membranes and the surrounding collagenous stroma into which microvilli projected. Since the intercellular canalicular system present between the tumor cells was continuous with the "peripheral canalicular system," both systems probably have a common function related to steroid metabolism. The intercellular and "peripheral" canalicular systems and cytoplasmic microfilaments found in this tumor suggest that this ovarian lipid cell tumor was derived from the ovarian stroma.     

Malignant oncocytoma of the parotid gland. A light and electron microscopic study.

A case malignant oncocytoma of the parotid gland occurring in a 91-year-old man is reported. The tumor recurred 10-months and 2 1/2 years after the primary excision. Both primary and recurrent tumors exhibited an infiltrative pattern. The histologic appearance of the original tumor and the recurrent lesion were similar, but there were areas of increased mitotic activity and pleomorphism in the latter. Ultrastructural examination of the recurrent tumor revealed that the cytoplasm was packed with mitochondria. The fine structure was, for the most part, similar to the benign variant reported previously. In the present tumor, however, intercellular spaces were more prominent and a basal lamina was not observed. The malignant oncocytoma occurs both in major and minor salivary glands. The tumor mostly affects the older age group, but the biologic behavior cannot be evaluated fully because of the paucity of cases reported and the lack of follow-up information.     

Dural cerebellopontine angle metastasis from malignant parotid oncocytoma

Malignant oncocytoma of the parotid gland is a quite rare tumor, with only 40 cases with unequivocal histological diagnosis reported in the literature. No cases with intracranial metastasis have been described. The authors report a very unusual case of malignant parotid gland oncocytoma with a large dural extracerebellar metastasis occurring in the contiguous cerebellopontine angle six months after surgery for the primary tumor. Only a partial removal of the dural metastasis was possible because of the cranial nerve and vessel encasement within the mass. Surgery and irradiation resulted in one-year survival. Interestingly, no destruction and infiltration of the petrous and temporal bones were found both at radiological and surgical exploration. We may suggest that metastatic spread from the parotid region to the cerebellopontine angle occurred through the mastoid cells or by haematogenous diffusion through the meningeal branches to the posterior fossa dura from the occipital or ascending pharyngealbreak arteries.     

Malignant paraganglioma of the peri-iliac artery

A malignant nonfunctioning paraganglioma of the pelvic retroperitoneum (left external iliac artery) with metastases to the femoral lymph nodes was found in a 68-year-old woman at exploratory laparotomy. Light microscopy showed a typical alveolar pattern with fine vascular stroma. The tumor cells had finely granular eosinophilic cytoplasm and oval to round nuclei with pleomorphism and mitotic figures, Grimelius stain showed no argyrophilic granules, but S 100 protein was demonstrated in the cytoplasm by the PAP method of Sternberger. Formaling fixed tissues were examination by electron microscopy, and dense core granules consistent with neurosecretory granules were found in the cytoplasm of some tumor cells.     

Pituitary oncocytomas: clinical features,characteristics in cell culture,and treatment recommendations

To determine whether there are significant differences between oncocytomas and pituitary adenomas, we evaluated clinical features, treatment regimens and outcome in 23 males and 9 females (average age 64 years, range 43–81 years) with the histologic diagnosis of pure pituitary oncocytomas (>95% oncocytes). Symptom duration was six to twelve months in 6 cases (19%) and more than one year in 19 cases (59%). Three patients presented with sudden onset of symptoms, and were found to have hemorrhage within their tumors. Visual loss (69%) and symptoms of hypopituitarism (44%) were the most common presenting complaints. Preoperative endocrine profiles revealed abnormalities in most cases, including pituitary insufficiency in 56% and hyperprolactinemia in 59%. The tumors were typically large at presentation; all but one had suprasellar extension. 28 patients underwent transsphenoidal tumor resections; 4 underwent subfrontal craniotomies. Gross dural invasion was found at surgery in 11 cases. At a mean followup of 31 months (range 2–68 months), recurrent tumor was identified in 4 patients (12.5%). Tumor size, dural invasion, preoperative endocrine profile, and postoperative radiotherapy did not correlate with recurrence. Among seven oncocytomas grown in culture, five demonstrated two distinct cell types consisting of oncocytes and typical adenoma cells, respectively. Oncocytomas often have a different clinical presentation than functional pituitary adenomas.     

Tumor cell characterization in mycosis fungoides.

Five patients with tumor stage mycosis fungoides had tumor lesions excised and examined by light and electron microscopy. The tumor cells were also isolated and the percentages of E rosettes (T cells) and EAC rosettes (B cells) were determined and the rosettes examined by electron microscopy. The predominant cell type isolated from four of the five tumors was a T cell. Peripheral lymphocyte function measured by LTT to phytohemagglutinin and pokeweed mitogen was normal. Serum immunoglobulins gave variable results. The results support the concept that mycosis fungoides is primarily a T cell tumor involving the skin and morphologically similar to the Sézary cell.