The changes in plasma electrolytes and blood pH and gases following the insufflation of air into the subarachnoid space for pneumoencephalography were investigated. The only significant change observed was a rapid fall of plasma potassium most evident at 60 minutes. A concomitant reduction of the urinary Na/K ratio supports the possibility that the change observed may be due to the stimulation of aldosterone secretion caused by this procedure, though its rapid occurrence and reversibility indicate that other influences might at least in part be responsible.

B c Within the pantheon of pathologists, Dr. William B. Bill) Ober (Figure 1) was a luminous figure with a unique ombination of erudition, wit, and sporadic bizarre behavior. ne of us (RES) was privileged to be among the many friends ho were awed by his extensive knowledge and entertained y his keen, off-beat humor and occasional mischievous onduct. Both of us have found Dr. Ober’s original publiations on pathology instructive and his many essays on onpathology topics both educational and entertaining. Dr. Ober was born in 1920, the only child of Jewish arents who lived on a fashionable street in Brookline, assachusetts. His father, Mr. Harry Ober, was a certified ublic accountant and his mother a homemaker. Bill adored is mother and grandmother, whose ancestors had emirated from Russia, but he argued often and vociferously ith his father. Bill graduated from Harvard College, magna um laude, in 1941. Because of congenital amblyopia (dimess of vision without a detectable ocular lesion) and a pinal disorder of unknown type, he was deferred from ilitary service during World War II. He graduated from oston University Medical School in 1946. He interned at he Beth Israel Hospital in Boston under the celebrated ardiovascular pathologist Dr. Monroe J. Schlesinger, who ave him a thorough education in the clinicopathological eatures of coronary heart disease, and subsequently under he eminent obstetrical-and-gynecological pathologist Dr. rthur T. Hertig, at the Boston-Lying-In Hospital (BLI) and

The differential diagnosis of ovarian tumors is reviewed based on their patterns and cell types. This approach, which differs from the standard textbook discussion of each neoplasm as an entity, has practical value as differential diagnosis depends largely on the pattern or patterns and cell type or types of tumors. Awareness of the broad range of lesions that may exhibit particular patterns or contain one or more cell types is crucial in formulating a differential diagnosis. The following patterns are considered: moderate-to-large-glandular and hollow-tubular; solid tubular and pseudotubular; cords and ribbons; insular; trabecular; slit-like and reticular spaces; microglandular and microfollicular; macrofollicular and pseudomacrofollicular; papillary; diffuse; fibromatous-thecomatous; and biphasic and pseudobiphasic. The following cell types are considered: small round cells; spindle cells; mucinous cells, comprising columnar, goblet cell and signet ring cell subtypes; clear cells; hobnail cells; oxyphil cells; and transitional cells. The morphologic diversity of ovarian tumors poses many challenges; knowledge of the occurrence and frequency of these patterns and cell types in various tumors and tumor-like lesions is of paramount diagnostic importance. A specific diagnosis can usually be made by evaluating routinely stained slides, but much less often, special staining, immunohistochemical staining or, very rarely, ultrastructural examination is also required. Finally, clinical data, operative findings, and gross features of the lesions may provide important, and at times decisive diagnostic clues.

The International Society of Gynecological Pathologists was founded in 1976 to facilitate an exchange of knowledge about gynecological disease throughout the world. The Society moved quickly to schedule companion meetings with established international and regional pathology and gynecology societies, including the International Academy of Pathology, its United States-Canadian Division, and the International Federation of Gynecology and Obstetrics, and to sponsor smaller meetings within individual countries. In 1981 the Society founded this journal, and in 1983, at the invitation of the World Health Organization, it assumed the responsibility of revising the WHO classifications of tumors of the female genital tract. The foundation of the Society appears to have been solid in view of its present robust health.

Ten endometrial stromal tumors of the uterus with a prominent myxoid or fibrous appearance, or both, that led to problems in interpretation are reported. The patients were 32 to 52 (mean 39) years of age. Three presented with dysfunctional uterine bleeding and one with abdominal pain. An enlarged uterus or a pelvic mass was palpated in five patients; the tumor was an incidental postpartum finding in one patient. All patients underwent hysterectomy. The tumors ranged from 4 to 20 cm in greatest dimension. Six were soft, polypoid intracavitary masses and four were predominantly intramyometrial; two were gelatinous. On microscopic examination, nine tumors infiltrated the myometrium (stromal sarcomas) and one was well circumscribed (stromal nodule). Six tumors had a predominantly fibrous component with the neoplastic cells separated by variable amounts of collagen; extensive areas of hyalinization were present in three tumors. Two tumors were predominantly composed of hypocellular areas with an abundant myxoid matrix, and two had both components in roughly equal proportions. Alcian blue staining was positive, with the staining eliminated by hyaluronidase predigestion, in the myxoid areas. The typical morphologic features of endometrial stromal neoplasia were present focally in four tumors. All of them contained numerous small thin-walled vessels. Vimentin and smooth muscle actin were positive in nine of nine and seven of nine tumors, respectively, whereas desmin was negative in six of nine tumors and only focally positive in the other three. One patient had omental nodules at the time of the initial diagnosis and another had a pelvic recurrence 2 years after hysterectomy. Follow-up information is unavailable or short in the other cases. These tumors should be considered of endometrial stromal origin in view of the typical location of most of them, their growth pattern, content of characteristic arterioles, presence of typical endometrial stromal neoplasia in the primary or recurrent tumor in some cases, and absence of evidence of origin from a cell type other than endometrial stroma. These tumors may be identical, in some instances at least, to tumors referred to in the older literature as "myxofibrosarcomas."

Steroid-hormone-producing ovarian tumors include those in which the neoplastic cells secrete hormones as well as a wide variety of tumors in which the neoplastic cells stimulate the ovarian stroma or adjacent hilus cells to become hormonally active.

Primary epididymal carcinoma is extremely rare and has been the subject of only sporadic case reports; the validity of some of the reported tumors is questionable. We report our experience with four examples, which arose in men 27, 66, 77, and 81 years of age. All of them presented with scrotal masses; three of them had small hydroceles. None had a history of von Hippel-Lindau disease. Grossly, all of the tumors were centered in the epididymis and two were confined to it. One tumor invaded the periepididymal soft tissue and spermatic cord and the fourth invaded the adjacent testis. They were 2.0-7.0 cm in greatest diameter; three had foci of hemorrhage and necrosis. Microscopically, all of the tumors were adenocarcinomas. Two of them were composed of approximately equal numbers of simple tubules and more complex tubulopapillary formations lined by cuboidal or columnar predominantly clear cells that infiltrated the epididymal smooth muscle wall, periepididymal soft tissue, or both. The other two had large cysts into which grew complex papillary or confluent, back-to-back glands lined by columnar cells with clear, lightly amphophilic or eosinophilic cytoplasm. Necrosis was present in three cases. An undifferentiated, sheetlike growth of anaplastic tumor cells was present focally in one case. Cilia were absent. Small amounts of cytoplasmic glycogen were present in the two cases in which periodic acid-Schiff staining was performed. Immunohistochemical staining, performed in one case, demonstrated strong positivity for cytokeratins (AE1/3, Cam 5.2) and epithelial membrane antigen (luminal only). Results of staining for carcinoembryonic antigen, Leu M1, B72.3, and Ber-EP4 were negative. Ultrastructural analysis, performed in one case, showed well-developed desmosomal junctions, cytoplasmic multivesicular bodies, glycogen particles, and well-developed cilia. Two of three patients with follow-up data died of disease 8 months and 2.5 years after diagnosis; the third was disease free 30 years after the diagnosis despite having paraaortic lymph node metastases at the time of presentation. After reviewing the literature and analyzing our cases, we conclude that bona fide examples of epididymal adenocarcinoma are usually tubular, tubulocystic, or tubulopapillary adenocarcinomas, often with an appreciable content of clear cells, which can usually be readily separated from other paratesticular malignant tumors, such as malignant mesothelioma and carcinomas of the müllerian type. Distinction from metastasis may be difficult and may depend largely on careful clinical evaluation.

Nine vulvar and three vaginal angiomyofibroblastomas from patients 23 to 71 years of age (mean, 46 yr) were analyzed. The tumors were well circumscribed and ranged from 0.9 to 11 cm (average, 4.7 cm) in maximal dimension. On microscopic examination, they had hypercellular and hypocellular areas. The neoplastic cells were spindle-shaped, plasmacytoid, or epithelioid; a variable number were binucleated or multinucleated cells. A focal storiform pattern was present in one tumor, and, in one tumor, the neoplastic cells formed a collar around a central area of dense collagen. There was no significant nuclear atypia, and there was less than one mitotic figure per 10 high-power fields. The tumors contained small- to medium-sized blood vessels, which were characteristically thin-walled and, occasionally, ectatic and branching. The stroma was edematous, separated collagen fibers and contained a Variable number of inflammatory cells, especially lymphocytes and mast cells. Three vulvar tumors contained a variable amount of fat. Ultrastructural study of three tumors showed intracytoplasmic, dilated, rough endoplasmic reticulum, moderate numbers of pinocytotic vesicles, and numerous filaments without dense bodies; rare intercellular rudimentary junctions were identified. Eleven of 11 tumors were immunoreactive for vimentin, 11 of 12 for desmin, three of 11 for muscle actin, one of 12 for smooth muscle actin, and four of 12 for CD34. There was no staining for factor Xllla, keratin, S100 protein, Leu-7, glial fibrillary acidic protein, or CD68. Follow-up revealed no recurrences or metastases. Angiomyofibroblastoma is a distinctive benign tumor that arises most commonly in the vulva and vagina and has a diverse histologic and immunohistochemical profile.

Prauson, R. A.; Hart, W. R.; Petras, R. E.; Young, R. H.; Gilks, C. B.; Scully, R. E.; Seidman, J. D.; Elsayed, A. M.; Sobin, L. H.; Tavassoli, F. A.