Placenta Increta Presenting as Exaggerated Placental Site Reaction

Exaggerated placental site (EPS) is usually an incidental finding seen in curettings after an abortion. Placenta increta is, by definition, a disease that damages and destroys myometrium; however, prior literature has not paid sufficient attention to the role of myometrium in its pathogenesis and diagnosis. We present an unusual case of placenta increta in a hysterectomy performed for uterine perforation after curettage for the termination of pregnancy at 18 weeks. The initial histologic section of the implantation site suggested EPS. Actin stains showed degenerated inflamed muscle at the EPS-like site, keratin stains showed interstitial trophoblast in the zone of myometrial damage, and the wall of the corpus was grossly thinned under the placenta. The myometrial damage may have softened the wall, predisposing to uterine perforation by the curettage procedure.

Detection of Sarcocystis Parasites in Retail Beef: A Regional Survey Combining Histological and Genetic Detection Methods

Sarcocystis spp. are parasitic protists acquired when undercooked, cyst-laden meat is consumed. While both Sarcocystis hominis and S. cruzi encyst in beef, only S. hominis is pathogenic to humans. In this study, we used histological methods and novel molecular techniques to determine the regional prevalence and identity of Sarcocystis spp. in retail beef. Of 110 samples, 60 supported amplification of parasite rRNA by PCR. All 41 sequenced representatives were identified as S. cruzi. To compare detection methods, 48 samples were then examined in parallel by histology and PCR, and 16 and 26 samples, respectively, were positive. Five samples positive by initial histologic sections were not amplified by PCR. Fifteen PCR-positive samples did not contain sarcocysts on initial histologic section, but additional sections from these samples revealed sarcocysts in an additional 12 samples. When combined, histology with additional sections and PCR detected 31 positive specimens of the 48 total specimens. We found no evidence of human pathogen S. hominis and confirm that cattle pathogen S. cruzi is highly prevalent in this regional sample. PCR assays may increase the detection sensitivity of Sarcocystis spp. and contribute diagnostic precision.

Correlations between Pathologic Changes in the Stapes and Conductive Hearing Loss in Otosclerosis

The goal of this temporal bone study was to quantify the relationship between specific histologic changes at the stapes footplate and the magnitude of the air-bone gap in otosclerosis. The study material comprised 26 specimens with otosclerosis and 37 age-matched controls. Detailed anatomic measurements were made on each histologic section through the stapes footplate in each bone, resulting in 30 different measurement parameters for each bone. For frequencies 250 to 2,000 Hz, the conductive hearing loss correlated highly with (p <.01) and appeared to be caused primarily by narrowing and loss of the annular ligament, especially at the posterior stapediovestibular joint space. The size of the air-bone gap appeared to be determined by the extent and degree of this pathologic change. Schuknecht's hypothesis that bony ankylosis of the footplate would be associated with an air-bone gap of >30 dB was supported by our data. However, the degree and extent of bony footplate ankylosis could not be reliably predicted by the size of the air-bone gap.