Hyperplastic and Neoplastic Lesions of the Mammary Gland in Macaques

Macaques provide an important animal model for the study of hormonal agents and their effects on risk biomarkers for breast cancer. A common criticism of this model is that spontaneous breast cancer has rarely been described in these animals. In this report, we characterize 35 mammary gland lesions ranging from ductal hyperplasia to carcinoma in situ and invasive ductal carcinoma in cynomolgus and rhesus macaques. Based on a retrospective analysis, we estimated the lifetime incidence of mammary gland neoplasia in aged female macaques to be about 6%. Hyperplastic lesions (n = 19) occurred segmentally along ducts and included such features as columnar alteration, micropapillary atypia, and fibroadenomatous change. in situ carcinomas (n = 8) included solid, comedo, cribriform, and micropapillary elements, encompassing 4 of the major architectural patterns seen in human lesions. invasive ductal carcinomas (n = 8) were generally solid, with prominent central necrosis and mineralization, often on a background of micropapillary ductal hyperplasia and in situ carcinoma. Cytologic changes of invasive lesions included increased mitoses, nuclear pleomorphism, extensive microinvasion, and stromal desmoplasia. Axillary lymph-node metastases were confirmed in 5 of the 8 invasive carcinomas. on immunohistochemistry, intraductal and invasive carcinomas had increased Ki67/MIB1 and HER2 expression and selective loss of estrogen and progesterone receptors. These findings suggest that breast cancer is an underreported lesion in macaques and highlight unique morphologic and molecular similarities in breast cancer between human and macaque species.

Intracranial lymphomas in simian retrovirus-positive Macaca fascicularis

Two young adult Macaca fascicularis each had unilateral mydriasis and ptosis. Both animals were euthanatized, monkey No. I for progressive neurologic signs and monkey No. 2 because of a positive intradermal tuberculin test. At necropsy, each animal had a single intracranial mass on the ventral surface of the midbrain, surrounding the oculomotor nerve. Histologically, both masses were immunoblastic lymphomas. Immunohistochemical staining revealed the neoplasms to be of B-cell origin. Simian retrovirus (SRV) was isolated from both monkeys, but simian immunodeficiency virus was not found. Both animals lacked antibody to SRV. Both animals had antibodies to Epstein-Barr-like virus (EBV), but EBV antigens were not found by immunohistochemistry. Polymerase chain reaction analysis for integrated EBV DNA was unproductive. One of the animals (monkey No. 2) had a pulmonary infection with Mycobacterium avium, suggesting that immunosuppression was present. These cases represent a unique and previously undescribed type of solitary lymphoma in SRV-infected macaques.

Disseminated blastomycosis in a rhesus monkey (Macaca mulatta)

An 8-year-old male rhesus monkey (Macaca mulatta) died following a 6-day illness consisting of progressive depression, anorexia, labored abdominal breathing, coughing, and tachypnea. Gross necropsy findings included severe multifocal (miliary) granulomatous pneumonia, granulomatous splenitis, and multifocal cerebral abscesses. Histologic examination revealed 10-15-microm broad-based budding organisms within pyogranulomatous inflammatory lesions in the lung, tracheobronchial lymph node, brain, spleen, and liver. The distribution of extrapulmonary lesions was intermediate between that described for dogs and that described for humans. These findings were consistent with blastomycosis, which is previously unreported in nonhuman primates.

Management of a pregnant patient with airway obstruction secondary to goitre

A case of airway obstruction in advanced pregnancy is presented. The patient was successfully managed with an awake fibreoptic intubation performed orally followed by a caesarean section and thyroidectomy as a combined procedure. On resection, a thyroid gland weighing 370 g was removed. The patient made an uneventful recovery.

Gas at abdominal US: appearance, relevance, and analysis of artifacts

PURPOSE

To describe the spectrum of ultrasonographic (US) appearances of intraluminal gas, including two clinically relevant gas artifacts.

MATERIALS AND METHODS

Observations were made in patients and reproduced in an animal model, an ex vivo gut preparation, and a tissue-mimicking phantom. Appearances were classified according to a physical model of the interaction between sound and collections of gas.

RESULTS

Free bubbles of gas appeared as bright echogenic foci extending artifactually owing to lateral and axial blooming. This causes bubbles that abut the gut wall to enhance the layer one echo, which corresponds to the interface between the mucosa and the luminal contents. Such bubbles can also falsely appear to be within the gut wall itself owing to elevation averaging and thereby cause the artifact pseudo-pneumatosis intestinalis. Isolated groups of small bubbles created a characteristic periodicity and tapering of the distal echo pattern. In the extreme case, in which many such echoes are superimposed, "dirty shadowing" occurs. A contiguous pocket of gas may cause the gut wall to appear artifactually thickened (i.e., pseudo-thickened gut). This was shown to be a form of mirror image artifact.

CONCLUSION

Classification of the effects of gas on US images according to their physical characteristics may aid in their interpretation. Appreciating two previously undescribed artifacts, pseudo-pneumatosis intestinalis and pseudo-thickened gut, will improve the usefulness of abdominal US.

Benign bronchial stenosis treated with balloon bronchoplasty and metal stents

We report a case of a benign bronchial stenosis that presented clinically with recurrent respiratory infections and increasing dyspnoea. This was associated with transradiancy and oligaemia of the ipsilateral lung. Treatment with balloon bronchoplasty and self-expanding metal stents prevented recurrent pneumonia and led to a sustained improvement in exercise tolerance.