Intraosseous echinococcosis: a rare manifestation of echinococcal disease.

We have presented a case of osseous echinococcosis and have reviewed the pathogenesis, pathology, diagnosis, and current treatment methods.

Squamous cell carcinoma infiltrating a pancreatic pseudocyst.

We have described a case of primary squamous cell carcinoma infiltrating a pancreatic pseudocyst, and have discussed pancreatic neoplasms arising in association with pseudocysts.

Malignant epithelioid schwannoma of the skin. A low-grade neurotropic malignant melanoma?

We studied a polypoid cutaneous neoplasm excised from the left arm of a 23-year-old man by light microscopy, immunohistochemistry, and electron microscopy. Histologically, the tumor was composed of a proliferation of round to oval epithelioid cells that were arranged in fascicles and showed a prominent perineural distribution. Immunohistochemistry revealed the presence of S-100 protein and vimentin within tumor cells. Electron microscopy demonstrated reduplication of basal lamina and abundant long-spacing collagen in intercellular spaces. The findings are consistent with a primary malignant epithelioid schwannoma of the skin. We discuss the relationship of this lesion with other neoplasms in the spectrum of tumors showing schwannian and melanocytic lines of differentiation.

Giant cell fibroblastoma. A report of a case and review of the literature.

A 15-year-old white boy with a giant cell fibroblastoma of the skin of the abdomen is described. Giant cell fibroblastoma is a rare soft tissue neoplasm that most commonly occurs in children as a small, painless mass in the dermis and subcutaneous tissue. Although local recurrences have been reported, no metastases have occurred. Giant cell fibroblastoma must be differentiated from other spindle cell neoplasms.

Metastatic renal cell carcinoma presenting as a parotid tumor: a case report with immunohistochemical findings and a review of the literature.

Renal cell carcinoma presenting as an asymptomatic parotid mass is rare. Only 15 cases have been reported. We describe a 72-year-old man with widespread metastatic renal cell carcinoma presenting with a 2-year history of a slowly enlarging left parotid mass. Needle biopsy revealed a clear cell neoplasm. Immunoperoxidase studies for carcinoembryonic antigen were negative while those for vimentin and keratin were positive, consistent with a renal cell carcinoma. This is the first case reported in which the immunohistochemical findings of positive staining for vimentin and keratin have confirmed the presence of metastatic renal cell carcinoma. The histochemical features of various parotid clear cell tumors, as well as a review of renal cell tumors presenting as a parotid mass, will be discussed.

Bowen's disease, Paget's disease, and malignant melanoma in situ.

The histologic differential diagnosis of skin lesions characterized by large, atypical, clear cells in the epidermis includes Bowen's disease, Paget's disease (mammary and extramammary), malignant melanoma in situ (pagetoid precancerous melanosis), mycosis fungoides, Spitz nevus, and artifact. Our experience with these lesions indicates that these diseases can be differentiated immunohistologically by the standard peroxidase-antiperoxidase technique, using antibodies directed against keratin (KER), carcinoembryonic antigen (CEA), and S-100 protein (S-100). Based on a study of 11 cases of Bowen's disease, eight cases of Paget's disease, and nine cases of malignant melanoma in situ, we conclude that the atypical clear cells of Bowen's disease stain only with antibodies to KER; those of Paget's disease, exclusively with antibodies to CEA; and those of malignant melanoma in situ, with antibodies to S-100. Additionally, we report a case in which clinical and histologic findings suggested Bowen's disease, but immunohistologic findings supported the diagnosis of Paget's disease.

Plasma hemoglobin determination by recording derivative spectrophotometry.

Recording derivative spectrophotometry (DS) is a technic for analyzing absorbance curves by measuring the derivative (slope) of those curves. The derivative is a mathematical function that enhances rapid changes of direction of a curve and suppresses slow changes. We are presenting a simple, rapid, and reproducible method for determining plasma hemoglobin concentration, even in the presence of bilirubin, myoglobin, or marked turbidity. No toxic reagents are used and, since the analysis is purely physicomathematic, the sample is not altered and can be used for additional tests.

Subcutaneous fibroadenoma on an arm.

A case of a subcutaneous fibroadenoma on an arm of an 18-year-old woman is presented. The neoplasm, thought clinically to be a lipoma, may have arisen in ectopic breast tissue. Dermatologists and dermatopathologists should be aware that fibroadenomas histologically identical with those seen in the breast have been observed along the milkline and may also occur in other sites.

Peritoneal keratin globules in uterine adenosquamous carcinoma.

We have described a previously unreported lesion--peritoneal keratin globules in uterine adenosquamous carcinoma. We postulate that the keratin globules are derived from sloughed uterine adenosquamous carcinoma which gains access to the peritoneum through retrograde dissemination via the fallopian tubes, and we suggest that the finding of these globules does not alter the prognosis and staging of the primary carcinoma.

Separation of bilirubin from hemoglobin by recording derivative spectrophotometry.

Recording derivative spectrophotometry is a technic for resolving overlapping absorbance curves by enhancing small changes in those curves. The derivative (slope) is a function sensitive to rapid changes in the curve and will amplify those regions while damping out slowly changing portions of curves. The method presented relies on a mathematical analysis of the composite absorption curve formed by bilirubin and hemoglobin. Data confirming the usefulness of this technic for reliably and quantitatively separating these two substances in aqueous solution are presented. Recording derivative spectrophotometry may be useful for analyzing amniotic fluid, urine, or other biologic fluids.

Ceroid granulomas in a tubo-ovarian cyst.

We have described a previously unreported lesion--ceroid granulomas in a tubo-ovarian cyst. We postulate that the ceroid granules in the histiocytes are derived from lipids within the foamy histiocytes which are often associated with tubo-ovarian abscesses.

The question of right ventricular hypertrophy in sudden infant death syndrome.

The relative weight of the free wall of the cardiac right ventricle was ascertained in 177 instances of the sudden infant death syndrome and 30 control infants who had died either in accidents (ten) or of fulminant illness (20). In contrast to the observations of Naeye et al in this regard, these victims of crib death did not exhibit right ventricular hypertrophy. Other evidence to support Naeye et al's contention that such infants are morphologically demonstrably different from normal is well documented. Hence, the significance of this discrepancy between our findings and theirs is unclear.

Ferrugination caused by Monsel's solution. Clinical observations and experimentations.

Ferrugination of fibrin, dermal collagen, and striated muscle fibers may result from the application of Monsel's solution (20% ferric subsulfate) for hemostasis to wounds caused by excisions of skin. The collagen fibers in the dermis are coated with a slightly refractile, gray-brown substance which is strongly positive with Perl's reaction for iron. Ferruginated collagen fibers are eliminated through the epidermis as the epidermis regenerates. Some of the ferruginated fibers become calcified. Siderophages are present in these and adjacent areas. Seepage of Monsel's solution into deeper tissues at the site of biopsy may result in ferrugination of skeletal muscle, perichondrium, and even cartilage. We applied Monsel's solution to biopsy sites caused experimentally in a rabbit and confirmed the capacity of the solution to produce ferrugination of collagen fibers and skeletal muscle. Ferrugination of collagen fibers becomes less pronounced as the wounds heal and as iron pigment is taken up by macrophages. Ferruginated fibers of skeletal muscle act as foreign bodies to elicit a granulomatous reaction. Comparison of biopsy sites to which Monsel's solution had been applied with biopsy sites to which the solution had not been applied indicates that the substance does not seem to interfere with the rate of epidermal regeneration. However, when there is injury to skeletal muscle and other deep tissues by Monsel's solution, an inflammatory reaction persists at these sites for weeks.

Ceroid granulomas of the gallbladder.

The authors report two cases of ceroid-containing granulomas of the gallbladder, an entity not previously reported in the American medical literature. They postulate that in some cases of chronic cholecystitis, bile provides the substrate for the formation of ceroid within histiocytes. The ceroid granulomas were incidental findings associated with chronic cholecystitis and cholelithiasis.