Hemangioma hemosiderótico en diana / Targetoid hemosiderotic hemangioma

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Regression of canine cutaneous histiocytoma: reduced proliferation or increased apoptosis?

BACKGROUND/AIM: Canine cutaneous histiocytoma (CCH) is a tumour that undergoes spontaneous regression. The aim of this study was to establish a possible relationship between regression of CCH and tumoural cell proliferation and apoptosis. MATERIALS AND METHODS: Immunostaining with Ki-67 antigen and the terminal deoxytransferase (TdT) deoxyuridine-5'-triphosphated (dUTP) nick-end labelling (TUNEL) method were performed on 93 specimens of CCH, grouped into four histological groups. RESULTS: The proliferative index evaluated with Ki-67 antigen expression was on average 23.56 ± 7.91%. The apoptotic index determined by the TUNEL method was on average 39.37 ± 5.87%. Neither the proliferative nor apoptotic index differed between histological groups. Moreover, the proliferative and apoptotic indices did not correlate significantly. However, apoptotic activity was higher than proliferative activity in almost all tumours. CONCLUSION: A reduction of proliferation or an increase of apoptosis does not appear to justify regression of CCH. However, our results suggest that an imbalance between cell proliferation and apoptotic cell death plays a significant role in spontaneous regression of CCH.

Positive surgical margins in soft tissue sarcoma treated with preoperative radiation: is a postoperative boost necessary?

PURPOSE: For patients with an extremity soft tissue sarcoma (STS) treated with preoperative radiotherapy and surgically excised with positive margins, we retrospectively reviewed whether a postoperative radiation boost reduced the risk of local recurrence (LR). METHODS AND MATERIALS: A total of 216 patients with positive margins after resection of an extremity STS treated between 1986 and 2003 were identified from our institution's prospectively collected database. Patient demographics, radiation therapy parameters including timing and dose, classification of positive margin status, reasons for not administering a postoperative boost, and oncologic outcome were collected and evaluated. RESULTS: Of the 216 patients with a positive surgical margin, 52 patients were treated with preoperative radiation therapy alone (50 Gy), whereas 41 received preoperative radiation therapy plus a postoperative boost (80% received 16 Gy postoperatively for a total of 66 Gy). There was no difference in baseline tumor characteristics between the two groups. Six of 52 patients in the group receiving preoperative radiation alone developed a LR compared with 9 of 41 in the boost group. Five-year estimated LR-free survivals were 90.4% and 73.8%, respectively (p = 0.13). CONCLUSIONS: We found that including the postoperative radiation boost after preoperative radiation and a margin-positive excision did not provide an advantage in preventing LR for patients treated with external beam radiotherapy. Given that higher radiation doses placed patients at greater risk for late complications such as fracture, fibrosis, edema, and joint stiffness, judicious avoidance of the postoperative boost while maintaining an equivalent rate of local control can reduce the risk of these difficult-to-treat morbidities.

[Antitumor cross-resistance of trichinosis]. / Protivoopukholevaia krossreziztentnost' trikhinoza.

Our experiments were concerned with formation of antitumor cross-resistance by Trichinella spiralis infection in rats. Prophylactic infection was followed by an insignificant decrease in the number of 3,4-benzpyrene-induced malignant fibrous histiocytoma. It also inhibited mammary gland cancer induced by 7,12-dimethylbenzo(a)anthracene. No significant influence on the formation of fibroadenomas as a side effect was reported.