About 75% of HS arise in the skin or soft tissues, with other organs being affected as follows: liver, 6%; heart, 5%; bones, 4%; spleen 3% [2].

• According to a retrospective study conducted in Mexico [3], cutaneous HS most commonly develop in the following regions of the human body: scalp and neck (37%), trunk (24%), face (20%). In the same study, tumor sizes ranging from a few millimeters to more than 30 cm have been reported. HS typically manifest in form of multiple, reddish blue or purple papules. As the disease progresses, these papules augment in size, their surface may ulcerate and become increasingly prone to bleed. Most patients diagnosed with this type of HS have a medical history of cancer, often of breast cancer treated with radiation therapy or by means of mastectomy.
• HS affecting soft tissues or internal organs may cause pain and exert local mass effects. Further symptoms may develop due to HS interfering with organ function, e.g., hepatic HS may be associated with jaundice and lead to hepatic failure [4], while cardiac HS may cause dyspnea, pericardial effusion and cardiac tamponade [5] [6]. Spontaneous tumor rupture has repeatedly been described and may lead to anemia, thrombocytopenia, and coagulopathy, or hemorrhagic shock [7] [8].
  

Hematogenous spread is common, and metastases most frequently develop in the lungs. Accordingly, patients may present with signs of lung cancer.

Additionally, patients may claim constitutive symptoms like fatigue, fever, night sweats and weight loss. Hemolytic anemia may be observed [9] [10].

• Thyroid Nodule

  Fine needle aspiration cytology from the thyroid nodule was suspicious. After blood transfusion, total thyroidectomy was performed. Postoperative histopathological examination of the specimen revealed hemangiosarcoma of the thyroid. [ncbi.nlm.nih.gov]

• Upper Abdominal Pain

  Case 1 was a 67-year-old man referred from a local hospital due to the finding of a liver tumor by sonography after having right upper abdominal pain for 1 week and body weight loss of 3 kg in 1 month. [journals.lww.com]

• Vascular Disease

  Initial clinical diagnostic impressions included pericarditis, vasculitis due to a collagen vascular disease, interstitial pneumonia, sarcoidosis, and metastatic adenocarcinoma ( n 13). [nature.com]

• Recurrent Fractures

  Abstract An 87-year-old man with Paget's disease of the left humerus was found to have a Paget's sarcoma upon pathologic examination of the left upper limb, which was disarticulated for severe pain and recurrent fractures. [ncbi.nlm.nih.gov]

• Scalp Mass

  The patient underwent an extended resection of the frontal and occipital scalp masses, measuring 6.0 2.5 cm and 1.0 1.0 cm, respectively, and a bilateral neck nodal dissection. [spandidos-publications.com]

Fine-needle aspiration biopsy and histopathological analysis of obtained specimens will reveal characteristic features. On the one hand, there are epithelioid cells lining small cavities that distantly resemble blood vessels. On the other hand, spindle-shaped sarcoma cells are present. They are generally arranged in strands and form the backbone of vessel-like structures. With regards to nuclei, aberrant mitotic figures are frequently observed [1]. There may be necrotic foci. Antibodies directed against vascular markers like CD31, CD34, and FLI1 may be used for immunohistochemical analyses to corroborate histological findings.

While this approach is feasible in case of superficial HS, a more extensive preparation is required to obtain tumor samples from other sites. Here, imaging techniques have to be applied first in order to confirm the presence of a local mass and to obtain information regarding its accessibility [11] [6].

• Bicarbonate Increased

  Serum bicarbonate increased within 24 h of pregabalin administration in mice and rats. Rats compensated appropriately, but mice developed metabolic alkalosis and increased blood pH. [ncbi.nlm.nih.gov]

• Pseudomonas

  Here, we hypothesized that EGFuPA-toxin, a bispecific ligand-targeted toxin (BLT) consisting of a deimmunized Pseudomonas exotoxin (PE) conjugated to epidermal growth factor and urokinase, would efficiently target and kill cells derived from canine hemangiosarcoma [ncbi.nlm.nih.gov]

Hemangiosarcoma (HS) is a rare malignant neoplasm originating from mesenchymal tissue, namely from endothelial cells. This neoplasm is often described as a spongy tumor composed of dysfunctional blood vessel cells that are positioned together by undifferentiated sarcoma cells arranged in strands. The tumor is well supplied with blood. It differs largely from its benign counterpart, the hemangioma; HS generally affect the elderly, grow rapidly and invasively, and metastasize early. Hemangioma is typically diagnosed in neonates, grows slowly and resolves spontaneously.

HS primarily develop in the skin, in superficial or deep soft tissues, but they may also affect the liver, spleen, heart, or any other organ [1]. Little is known about the disease' etiology, but patients suffering from chronic lymphedema as well as those who received radiation therapy are known to be predisposed for HS [2]. It has been suggested that the growing number of patients exposed to therapeutic radiation accounts for the observed increase in HS incidence rates.

Of note, HS is a rather common diagnosis in veterinary medicine. Dogs are most frequently affected, but this tumor is also diagnosed in other species of domestic and wild animals. In order to avoid confusion between human and non-human HS, the term angiosarcoma is sometimes preferred for the disease of men. In any case, research concerning human HS is complicated by the low incidence of the disease. This does not apply to veterinary medicine and research; efforts made in this discipline may eventually allow the design of target-oriented studies in humans.

1. Geller RL, Hookim K, Sullivan HC, Stuart LN, Edgar MA, Reid MD. Cytologic features of angiosarcoma: A review of 26 cases diagnosed on FNA. Cancer Cytopathol. 2016;124(9):659-668.
2. Young RJ, Brown NJ, Reed MW, Hughes D, Woll PJ. Angiosarcoma. Lancet Oncol. 2010;11(10):983-991.
3. Albores-Saavedra J, Schwartz AM, Henson DE, et al. Cutaneous angiosarcoma. Analysis of 434 cases from the Surveillance, Epidemiology, and End Results Program, 1973-2007. Ann Diagn Pathol. 2011;15(2):93-97.
4. Abegunde AT, Aisien E, Mba B, Chennuri R, Sekosan M. Fulminant hepatic failure secondary to primary hepatic angiosarcoma. Case Rep Gastrointest Med. 2015;2015:869746.
5. Ge Y, Ro JY, Kim D, et al. Clinicopathologic and immunohistochemical characteristics of adult primary cardiac angiosarcomas: analysis of 10 cases. Ann Diagn Pathol. 2011;15(4):262-267.
6. Patel SD, Peterson A, Bartczak A, et al. Primary cardiac angiosarcoma - a review. Med Sci Monit. 2014;20:103-109.
7. Xu B, Xie X, Zhou X, Zhai M, Yang W. Spontaneous rupture of primary splenic angiosarcoma: A case report. Oncol Lett. 2015;10(5):3271-3273.
8. Tang K, Shang QL, Zhou QC, Zhou JW, She XL, Zhang M. Primary cardiac angiosarcoma with spontaneous ruptures of the right atrium and right coronary artery. Echocardiography. 2013;30(6):E156-160.
9. Dalal B, Al Riyami A, Yenson P. Microangiopathic haemolytic anaemia and hyposplenism in angiosarcoma. Br J Haematol. 2010;151(5):413.
10. Fong CY, Low M. An unusual case of microangiopathic hemolytic anemia resulting from metastatic angiosarcoma. Blood. 2013;122(1):7.
11. Koyama T, Fletcher JG, Johnson CD, Kuo MS, Notohara K, Burgart LJ. Primary hepatic angiosarcoma: findings at CT and MR imaging. Radiology. 2002;222(3):667-673.