FIGURE 3 - available via license: Creative Commons Attribution 4.0 International
Content may be subject to copyright.
![| Morphological comparison between anastomosing hemangioma [case 3. (A): ×40 magnification. (B): ×400 magnification] and angiosarcoma [case 4. (C): ×40 magnification. (D): ×400 magnification]. Angiosarcoma shows significant cytologic atypia, endothelial cell multilayering and broadly infiltrative pattern.](publication/362402386/figure/fig1/AS:1184348896272384@1659382189227/Morphological-comparison-between-anastomosing-hemangioma-case-3-A-40.png)
| Morphological comparison between anastomosing hemangioma [case 3. (A): ×40 magnification. (B): ×400 magnification] and angiosarcoma [case 4. (C): ×40 magnification. (D): ×400 magnification]. Angiosarcoma shows significant cytologic atypia, endothelial cell multilayering and broadly infiltrative pattern.
Source publication
Anastomosing haemangioma (AH) is a newly described distinct vascular neoplasm that histologically may confuse with well-differentiated angiosarcoma (AS) for those who are unfamiliar with this rare entity. We aimed to identify molecular genetic differences between AHs and ASs by carrying out immunohistochemistry (IHC), fluorescence in situ hybridiza...
Contexts in source publication
Context 1
... histologic features of all AHs consisted of capillary-sized vascular channels in lobulated and solid patterns with rare mitoses. Hobnailing of endothelial cells with mild cytologic atypia was also noted (Figure 1 case 1-3). Vessels containing thrombi and intracytoplasmic eosinophilic globules were found in all three cases, whereas extramedullary haematopoiesis was absent. ...
Context 2
... to its rarity and overlapping morphological features, AH may be confused with other vascular tumours particularly welldifferentiated AS due to the mild hyperchromatic, hobnail-like endothelial cells. Nevertheless, AHs usually possess differentiating factors such as the presence of lobulated contours and absence of prominent nuclear atypia, multilayering nuclei, high mitotic activity, infiltratingdissecting growth pattern and massive tumour necrosis (Figure 3). In our study, the mitotic activity labelled by MIB-1 in our three AH cases was less than 1% compared ASs (>50%). ...
Citations
Aims
Anastomosing haemangiomas are benign tumours with anastomosing vascular channels that may mimic angiosarcoma. While anastomosing haemangiomas have been described in diverse locations, particularly the abdominal/paraspinal region, data on anastomosing haemangiomas in the mediastinum remain limited. We report the clinicopathological, radiological and molecular characteristics of the largest single‐institutional series of mediastinal anastomosing haemangiomas.
Methods and results
In our pathology archives in 2011–23, we reviewed all vascular lesions involving the mediastinum and identified seven anastomosing haemangiomas. Clinical information was abstracted from medical charts; available radiological imaging was reviewed. Targeted DNA‐based next‐generation sequencing (447 genes, including GNAQ and GNA11 ) was performed on five cases. The seven patients included five women and two men, with an age range of 55–77 (median = 72) years. Of the six tumours with available radiology, two each were in the prevascular, visceral and paravertebral mediastinum, with lobulated peripheral enhancement in all tumours examined with contrast enhancement. Six patients underwent tumour resection; one patient received proton radiotherapy. Microscopically, each tumour was solitary and characterised by anastomosing capillary‐sized vessels lined by hobnail endothelial cells. Fibrin microthrombi, hyaline globules and extramedullary haematopoiesis were common. In the five tumours analysed by next‐generation sequencing, GNAQ p.Q209P was identified in one tumour; no additional reportable alterations were identified in the remaining cases. No recurrence was noted in the four patients with available follow‐up of 3–58 (median = 9.5) months after resection.
Conclusion
While mediastinal anastomosing haemangiomas can microscopically mimic angiosarcoma, awareness of this entity and radiological correlation may help to circumvent this diagnostic pitfall.
