Macroscopic and histological characteristics of fluid-filled ovarian structures in dairy cows

The primary objective of this study was to use macroscopic and histological features of corpora lutea with a cavity and anovulatory cystic ovarian structures, present in 90 pairs of abattoir-derived dairy cow ovaries, as the basis to clarify the nomenclature of ovarian structures. Excluding morphologically normal ovarian fol-licles (antrum < 2 cm, wall < 1 mm), there were 27 fluid-filled ovarian structures. Ovulatory structures > 16 mm in diameter were designated as Group A (cavity ≤ 10 mm and wall > 10 mm) or Group B (cavity > 10 mm and wall < 10 mm). The volume of luteal tissue was less (P < 0.05) in Group B than in Group A, whereas that of a solid corpus luteum (CL) was intermediate (least square means ± SEM: 72 ± 1.92, 11.22 ± 1.57 and 5.84 ± 1.92 cm3, respectively). There was a greater proportion (P < 0.05) of small luteal cells in Group B compared to a solid CL, whereas Group A was intermediate (58.6 ± 5.3, 37.4 ± 5.3 and 44.0 ± 4.4%, respectively). Connective tissue was thicker (P < 0.05) in Group B than in Group A (295.4 ± 46.9 vs. 153.9 ± 38.2 μm). Based on the above-mentioned characteristics and differences, Groups A and B were designated as a CL with a cavity and a cystic CL, respectively. Furthermore, there were three groups of anovulatory ovarian structures. Structures in Group C were termed persistent/anovulatory follicles (overall diameter and wall thickness ≤ 20 and 1–3 mm, respectively). Finally, Groups D and E were designated as a follicle-fibrous cyst and a follicle-luteinised cyst (based on histological structure) for anovulatory structures with an overall diameter and wall thickness of ≥ 20 and ≤ 3 mm, and ≥ 20 and ≥ 3 mm, respectively.

Mesenteric cyst

Mesenteric cysts are rare abdominal findings. Due to absent or unspecific clinical presentation, very low incidence, and lack of adequate classification these cysts may sometimes represent a diagnostic and therapeutic challenge. We report a case of 37-year-old man with vague palpatory tenderness in left hypochondrium and paraumbilically and with palpable large intra-abdominal mass in whom mesenteric cyst was diagnosed using US and CT imaging. He was operated and cyst was extirpated in toto. Histopathological examination revealed a thick fibrous cyst wall with the signs of chronic inflammation and without inner epithelial lining, which suggested its traumatic origin. Considering the possibility of malignancy mesenteric cysts should be radically resected (with resection of adjacent organs if necessary) due to their strong relapsing potential and a tendency for sudden, progressive local enlargement if not removed in toto.

Cyst of the Ligamentum Flavum: Report of Six Cases

Six cases of cyst of the ligamentum flavum with compression of a lumbar nerve root are reported. All patients exhibited recurrent back pain and sciatica. Investigation included computed tomography, myelography, or both. The correct diagnosis was reached before operation in only half the patients. High-resolution computed tomography performed in the four last patients outlined the cystic lesion with its low-density center. Surgical excision was performed in all patients. Microscopic examination showed a dense fibrous cyst arising from the ligamentum flavum. The lumen contained myxoid or necrotic material, but no epithelial lining. Cysts of the ligamentum flavum must be considered in the differential diagnosis of causes of sciatica. A firm radiological diagnosis may, at present, still require myelography combined with high-resolution computed tomography. Differentiation from synovial or ganglion cysts of the spine is discussed.

Formation of the cyst wall and related changes in the structure of the tegument ofBucephalus haimeanus(Lacaze-Duthiers, 1854) during its metamorphosis from the cercarial to the metacercarial stage

SUMMARYThe formation of the cyst wall surroundingBucephalus haimeanusand the related changes in the parasite tegument during its metamorphosis from the cercarial to the metacercarial stage have been investigated by means of experimental infections inGobiusculus flavescens. The initial fibrous cyst wall is formed from secretions produced by both the anterior gland cells and the tegument of the parasite. These secretions gradually become compacted against the surrounding hepatic cells until by the 20–30th day post-infection the 3-zoned inner layer, characteristic of the fully developed cyst wall, is formed. Hepatic cells immediately adjacent to this inner cyst wall layer are disrupted by the arrival of the metacercaria and form the middle vacuolated layer. As the metacercaria grows, the cyst increases in size causing still further hepatic cells to become flattened and incorporated into the cyst structure forming the outer nucleated layer. The structure of the cercarial tegument is described. Development of the metacercarial tegument is accomplished by the sequential movement of secretory vesicles from tegumental cell bodies into the outer cytoplasmic tegument. Vesicles of the types V. 1–5 are released from the outer cytoplasmic tegument, resulting in an almost complete breakdown of this layer prior to its replacement by the tegument of the fully developed metacercaria. The latter is characterized by the V. 6–9 type vesicles, dorso-ventrally flattened spines which terminate in 5–7 digits and by sensory cilia.