Disseminated hyaline ring granuloma in the omentum of a dog

Abstract Background Hyaline ring granuloma (HRG) is an uncommon histopathologic finding of unsolved etiopathogenesis. According to the exogenous theory, HRG develops due to implantation of foreign material, most probably indigestible plant fragments. HRG is a comparatively rare condition in humans, mostly involving the oral cavity with very rare extraoral locations. Case presentation An 1-year-old mixed-breed dog in good condition was presented for routine ovariohysterectomy. Disseminated HGR were accidentally found in the omental adipose tissue during surgery. Histopathology revealed the presence of ring-like hyaline structures surrounded by granulomatous inflammation including foreign body-type multinucleated giant cells. The histochemical examinations indicated the exogenous plant origin of the foreign material. Conclusions The lesions were similar to the findings in humans with HRG. The definitive diagnosis remains largely based on histopathological examination supported by special histochemical stains. To the best of our knowledge, this is the first case of hyaline ring granuloma reported in a non-human species. Moreover, the omentum is an uncommon location for this condition

Diagnostic efficacy of smear cytology and Robinson’s cytological grading of canine mammary tumors with respect to histopathology, cytomorphometry, metastases and overall survival

<div><p>Cytology is a simple, rapid, and inexpensive method used for pre-operative diagnosis of canine mammary tumors (CMTs) in veterinary practice. Studies related to human breast cancer showed the Robinson’s grading system—established for invasive ductal carcinoma, not otherwise specified (IDC, NOS) and used on cytological material—to not only closely correspond to the histopathological grading but also be helpful in assessing prognosis and selecting most suitable treatments before surgery. The objectives of this study were: to evaluate the accuracy of cytological diagnosis and cytological Robinson’s grading system compared to the histopathological examination of CMTs; to compare of cytological features and cytomorphometric parameters with tumor behavior, as well as cytological and histological grading; and to determine an association of the Robinson’s grading system and cytological background details with metastases, and patients’ survival. We report substantial diagnostic accuracy in detecting simple types and high grade tumors. Cytological diagnosis of tumor behavior showed relatively low sensitivity and specificity compared to human studies, and this might be caused by the heterogeneous morphology of CMTs. The presence of mucosecretory material and extracellular matrix was not significantly associated with tumor behavior. We report a positive correlation between both grading systems and cytological features (included in Robinson’s grading), the presence of necrotic debris, inflammation, and red blood cells. A negative correlation was determined only for the presence of extracellular matrix. The univariate and multivariate analyses confirmed a significantly higher risk of developing metastasis and shorter overall survival for dogs with tumors of grade 2 or 3 on cytology. In addition, these tumors were the most common cause of CMT-related deaths in dogs. Taken together, our findings suggest that the Robinson’s method of cytological grading applied for malignant CMTs evaluated in cytological smears regardless of tumor type can be adapted to veterinary cytology. Additionally, some background features seem to aid malignancy assessment.</p></div

Univariable overall survival analysis of dogs with CMTs in relation to cytological examination.

<p>Univariable overall survival analysis of dogs with CMTs in relation to cytological examination.</p

The numbers and percentages of each CMT based on tumor behavior (benign/malignant) and tumor type determined by cytology (CP) and histopathology (HP, definitive diagnosis) without showing variations in diagnoses between CP and HP (n = 73).

<p>The numbers and percentages of each CMT based on tumor behavior (benign/malignant) and tumor type determined by cytology (CP) and histopathology (HP, definitive diagnosis) without showing variations in diagnoses between CP and HP (n = 73).</p

Cytological and histopathological samples of malignant CMTs.

<p><b>Cytological smears were stained with Giemsa, while histopathological samples with hematoxylin and eosin method.</b> Simple carcinoma (A, B–cytology; C–histopathology); Complex carcinoma (D, E–cytology; F–histopathology), an arrow indicates the extracellular matrix; Carcinoma arising in benign mixed tumor (G, H–cytology; I–histopathology). Original magnification: (A, C, D, F, G, I) 100x; (B, E, H) 400x.</p

Cytological features in cytological samples from benign (n = 18) and malignant (n = 55) mammary tumors ultimately diagnosed by histopathology.

<p>Cytological features in cytological samples from benign (n = 18) and malignant (n = 55) mammary tumors ultimately diagnosed by histopathology.</p

The comparison of the cytopathological results according to the histopathological diagnosis for the differentiation of benign tumors, simple carcinomas and complex carcinoma/carcinoma arising in BMT/other malignant tumors (n = 73).

<p>The comparison of the cytopathological results according to the histopathological diagnosis for the differentiation of benign tumors, simple carcinomas and complex carcinoma/carcinoma arising in BMT/other malignant tumors (n = 73).</p

Cytological features in cytological samples from benign (n = 18) and malignant (n = 55) mammary tumors ultimately diagnosed by histopathology.

<p>Cytological features in cytological samples from benign (n = 18) and malignant (n = 55) mammary tumors ultimately diagnosed by histopathology.</p

Univariable analysis of cytological features in association with metastases 2 years after the mastectomy.

<p>Univariable analysis of cytological features in association with metastases 2 years after the mastectomy.</p

Robinson’s grading system described by Robinson et al. [15].

<p>Robinson’s grading system described by Robinson et al. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0191595#pone.0191595.ref015" target="_blank">15</a>].</p