Histologic Interpretation of Cutaneous Biopsies from Dogs with Dermatologic DisordersRojko, J. L.; Hoover, E. A.; Martin, S. L.
doi: 10.1177/030098587801500501pmid: 152500
Clinical and histologic data were correlated on skin biopsies from 238 dogs with various cutaneous disorders. Biopsies from normal dogs were used to establish normal histologic anatomy.Seborrhea was characterized by acanthosis, mild hyperkeratosis or parakeratosis, and mild mixed inflammatory cell infiltration. Dogs with allergic dermatitis had similar epidermal changes; however, dermal edema and pronounced mast cell infiltration distinguished this group. Biopsies from dogs with pyoderma revealed intense purulent inflammation of either the epidermis or hair follicles. Lesions of demodectic acariasis were most similar to those in the pyoderma group; specific diagnosis was based upon the presence of mites in follicles.Cutaneous lesions of hypothyroidism were classified into two categories—classical and seborrheic. The more common classical form was characterized by atrophic telogen phase hair follicles and marked hyperkeratosis of the external root sheath. Inflammation was absent. In the seborrheic form, telogen phase hair follicles were associated with acanthosis and mild mixed inflammatory cell infiltration. Hyperadrenocorticism was marked by more consistent epidermal and adnexal atrophy, telogen phase follicles, and hyperkeratosis of the epidermis and follicular root sheath. Dermal mineralization or decreased dermal thickness, or both, occurred in seven of 11 dogs (60%) with hyperadrenocorticism.
Canine Medullary Carcinoma of the ThyroidPatnaik, A. K.; Lieberman, P. H.; Erlandson, R. A.; Acevedo, W. M.; Liu, S.-K.
doi: 10.1177/030098587801500502pmid: 716155
An 8-year-old male Irish Terrier dog and a male St. Bernard dog each had a thyroid medullary carcinoma. The first dog was hypocalcemic before removal and with recurrence of the neoplasm. In both dogs the neoplasms were bilateral and microscopic metastases were seen only in the regional lymph nodes. Both neoplasms were characterized by a solid alveolar pattern separated by thin vascular stroma or a linear festoon-like arrangement with thick stroma. The neoplastic cells varied little and were polygonal or round with abundant pale eosinophilic and finely granular cytoplasm. There was little mitotic activity. Both carcinomas contained amyloid. Electron microscopically, the neoplastic cells had moderate nuclear pleomorphism, well developed Golgi complexes, and characteristic membrane-bound electron-dense secretory granules. In some sections, the secretory granule membranes were fused to the cytoplasmic membrane and the granules were in the extracellular space. In one carcinoma there were linear fibrillar structures with an average width of 7.8 nanometers similar to that of amyloid fibrils.
Canine Gastric AdenocarcinomaPatnaik, A. K.; Hurvitz, A. I.; Johnson, G. F.
doi: 10.1177/030098587801500503pmid: 716156
In a retrospective study of 26 gastric adenocarcinomas of the dog, 17 were found to have histologic features of the diffuse type and nine of the intestinal type similar to those of the same tumor in man. The intestinal type was characterized by distinct glandular structures lined with well polarized cells at the primary and metastatic sites and mild desmoplastic reaction. Three subtypes with distinct histologic features (papillary, five; acinar, three; solid, one) were recognized in this group. Fourteen of the diffuse adenocarcinomas were characterized by random infiltration by neoplastic cells, singly or in clusters, often with signet ring cells and severe desmoplastic reaction. The remaining three diffuse adenocarcinomas also had recognizable acinar structures and were considered to be glandular subtypes of the diffuse type.In eight dogs there was a 7:1 male to female ratio for dogs with the intestinal type and in 16 dogs a 2:1 male to female ratio for dogs with the diffuse type. Two of the nine intestinal type of adenocarcinomas, but none of the diffuse tumors, had intraluminal growths. Metaplasia of gastric epithelium was seen in nearly half the tumors; this was more common in the intestinal type (six of nine). Different degrees of carcinomatosis were seen in 24 of 26 dogs. Regional lymph nodes were involved in the 20 dogs whose nodes were available for examination. Distant metastases were seen in 19 of 26 dogs; liver, lungs and adrenal glands were the most common sites. Various degrees of lymphoid cell infiltration, suggesting the antigenic quality of the neoplasms, were seen in 15 dogs. Additional neoplasms were seen in eight dogs.
Beiträge zum Lebenszyklus der Frenkelien. IV. Pathomorphologische Befunde an den Organen experimentell infizierter RötelmäuseGeisel, O.; Kaiser, E.; Krampitz, H. E.; Rommel, M.
doi: 10.1177/030098587801500505pmid: 362689
In 1975 the buzzard (Buteo buteo) was found to be the final host of Frenkelia clethrionomyobuteonis. After this discovery it became possible to investigate systematically the pathomorphology of the infection in the intermediate host, the bank vole (Clethrionomys glareolus).Fifty bank voles were infected orally with a suspension of sporocysts recovered from the faeces of experimentally infected buzzards. Each rodent received 7000 sporocysts. Six controls each were given a faecal suspension from a non-infected buzzard. The voles were killed between 1 and 140 days after infection and examined histologically.Between the 5th and 8th day of the infection during the schizogonic multiplication of the parasite a focal necrosis of liver cells and of the liver parenchyma is observed followed by a reversible resorptive inflammation associated with siderophagia and the occurrence of giant cells. The spleen was spodogenously enlarged up to twice its normal size. There also was haemosiderosis of the bone marrow, the liver and the spleen up to 25 days after infection. At the same time the erythropoiesis in the bone marrow, the spleen and in the lymph nodes increased; there also was a lymphoid hyperplasia in spleen and lymph nodes. About 10 days after infection a reversible infiltration with lymphocytes and plasma cells developed in the liver, heart and brain. This infiltration was again detectable as perivascular and meningeal reactions in the brain after the 49th day after infection. The second asexual multiplication of the parasite was seen histologically in the grey and white matter of the central nervous system after the 18th day of infection. The developing cysts increased in size continuously thereby compressing the surrounding nervous tissue. Disseminated focal necrosis with resorptive inflammatory components was prominent in the parenchyma of the brain after the 49th day of infection.It was possible to differentiate between damage in single organs and systemic pathological lesions. The lesions in single organs were directly connected with the development of parasitic stages in the liver (schizonts) and in the brain (cysts). The generalized lesions occurred in the haemopoietic system after an impairment of the blood during the first asexual multiplication. They also occurred in the immunocytic systems after the first and during the second asexual multiplication and during the relatively late cystic phase of the parasite in the brain. The pathogenesis of the disintegration of blood cells is not clear. The immunocytic reaction can be considered an immunological response of the host against the parasite. The effect of the development of the cysts on the function and structure of the central nervous system is expected to lead to an increasing impairment of the motility of the intermediate host.
A Freeze-Etching Study on Experimental Murine MastitisSmith, K.; Chandler, R. L.
doi: 10.1177/030098587801500507pmid: 362690
Streptococcal mastitis was produced experimentally in mice inoculated by the intramammary route; freeze-etched preparations from the affected mammary glands were studied by electron microscopy. The inoculated cocci were seen free in the acinar lumen, within luminal phagocytes and within cells of the epithelium. No significant pathological changes were noted in the junctional complexes between secretory epithelial cells. The results were comparable to those obtained by ultrathin sectioning and indicated that, while cocci can transfer from the acinar lumen into the substance of the epithelium and towards a subepithelial location, the junctional complexes between epithelial cells present a potential barrier to movement through the intercellular spaces.
The Goitrogenic Effect of 4,4'-Oxydianiline in Rats and MiceHayden, D. W.; Wade, G. G.; Handler, A. H.
doi: 10.1177/030098587801500508pmid: 716159
Fischer 344 rats and B6C3F1 mice were fed diets that contained 0.03, 0.06, 0.1 and 0.2% 4,4'-oxydianiline for 13 weeks. The 0.1 to 0.2% diet caused 40 to 70% mortality in female rats. Although mice ate about 3.5 times more chemical than rats, no mice died. Alopecia, dyspnea and cyanosis in rats, and lethargy in both species occurred in the 0.1 to 0.2% groups. Goiter was found in rats that died as early as the 4th to 5th week of study in the groups given the 0.06 to 0.1% diet. At the end of the study, diffuse parenchymatous goiter was seen in all rats given the 0.06% and higher concentration diets and in most mice given the 0.2% diet. In rats, the thyroids also were heavily encapsulated and had interstitial fibrosis and vascular degeneration. There was concomitant hyperplasia of pituitary basophils in both species, but an increase of cells that secrete thyrotropin was seen in rats only.