Hemangiopericytoma

The hemangiopericytoma is a tumor belonging to the group of sarcomas . Hemangiosarcomas occur in the area of the soft tissues , especially in the subcutaneous tissue , as well as in the meninges .

The cell type responsible for the degeneration is still unknown. While some authors classify the tumor in the group of cells around the blood vessels ( perivascular wall tumors ), others classify it in the group of nerve sheath tumors . In the older literature, the hemangiopericytoma is also counted as a fibrosarcoma . Immunohistochemically, the tumor reacts positively to S 100 , CD34 , CD99 and mostly also α- smooth muscle actin is rich in vimentin .

Occurrence

In humans, soft tissue hemangiopericytomas occur primarily in the extremities, pelvis, and head and neck area. In addition, they are also found in the meninges and make up about 2% of meningeal tumors here. They are among the benign or semi-malignant tumors.

Hemangiopericytoma is a common soft tissue tumor in domestic dogs. It accounts for around 4% of all skin tumors or a third of all soft tissue sarcomas. In two thirds of the cases, the tumor occurs on the extremities, especially the upper arm and thigh. A breed cluster has been described for the German Shepherd , German Boxer , Doberman , Airedale Terrier , Poodle and Spaniel . Affected animals are usually older than nine years.

Clinical picture

The hemangiopericytoma occurs as a soft subcutaneous tumor that cannot be distinguished from a lipoma by touch . As the disease progresses, it can also infiltrate the overlying skin and lead to hair loss, ulcers and bleeding . In the section, the tumor is reminiscent of adipose tissue interspersed with connective tissue . The onion skin-like capsule consists of compressed tumor cells. However, it does not represent the real tumor boundary. Because tumor extensions that are invisible to the naked eye can radiate from the capsule into the neighboring tissue.

The soft tissue hemangiopericytoma tends to grow locally invasively. However, metastases in the lungs or in regional lymph nodes are rare. Meningeal hemangiopericytomas have a high recurrence rate and often form distant metastases.

Diagnosis

The diagnosis is made on the basis of a cytological examination of a fine needle aspirate . Obtaining sufficient cell material can be difficult due to the strong tendency to bleed. In the microscopic image, spindle-shaped or plump cells can be detected that are drawn out like a tail or whip. The cell nuclei are oval, have a fine-grained chromatin and one or two nuclear bodies . Sometimes the cells can contain two or more cell nuclei ("bird's eye cells").

The risk of metastasis can be estimated based on the number of mitoses . More than 10% Ki-67 positive cells or more than 25% PCNA positive cells are prognostically unfavorable.

The hinhaut-hemangiopericytoma of man are less than 5 mitoses per 10 main fields of view in the WHO grade classified II, wherein more mitoses, upon the occurrence of necrosis or cell nucleus strong variability in the level III.

treatment

Surgical removal is the method of choice, with a generous distance of 1–2 cm beyond the pseudocapsule. This is usually more difficult to achieve on the limbs than on the trunk. If tumor cells are still detectable in the remaining tissue (“tumor bed”) in the subsequent histopathological examination, irradiation is indicated. In the case of large inoperable tumors, palliative radiation therapy can also be carried out.

With complete and timely removal and low mitotic values, the chances of recovery in the dog are very good. If the tumor is removed within the first two months after its appearance, the recurrence rate is 5%, if it is removed later it is 44%. With a mitotic index <9, the mean survival time is 37 months, with an index> 9 it is reduced to 49 weeks. If necrosis already occurs in the tumor , there is also a shorter survival time.

literature

Martin Kessler (editor): Small animal oncology: diagnosis and therapy of tumor diseases in dogs and cats . Georg Thieme, Stuttgart, 3rd edition 2012, ISBN 978-3-8304-1137-6 , pp. 206-207.

Individual evidence

↑ ^a ^b ^c Uwe Schlegel: Neurooncology . Georg Thieme, Stuttgart 2003, ISBN 978-3-1310-9062-1 , p. 44.
↑ ^a ^b Martin Breitenseher (editor): Imaging diagnostics and treatment of soft tissue tumors: with pathological classification, nuclear medicine, interventional therapy . Georg Thieme, Stuttgart 2008, ISBN 978-3-1314-3131-8 , p. 43.
↑ ^a ^b Martin Kessler (editor): Small animal oncology: diagnosis and therapy of tumor diseases in dogs and cats . Georg Thieme, Stuttgart, 3rd edition 2012, ISBN 978-3-8304-1137-6 , p. 206.
↑ Werner Paulus, J. Michael Schröder (Ed.): Pathology: Neuropathology . Springer, 3rd edition 2011, ISBN 9783642023248 , p. 526
^ Roche Lexicon Medicine , 5th edition, Urban & Fischer , Munich and Jena 2003, ISBN 3-437-15156-8 , page 755.
↑ Martin Kessler (editor): Small animal oncology: diagnosis and therapy of tumor diseases in dogs and cats . Georg Thieme, Stuttgart, 3rd edition 2012, ISBN 978-3-8304-1137-6 , p. 207.

[Schlegel-1] Uwe Schlegel: Neurooncology . Georg Thieme, Stuttgart 2003, ISBN 978-3-1310-9062-1 , p. 44.

[Breitenseher-2] Martin Breitenseher (editor): Imaging diagnostics and treatment of soft tissue tumors: with pathological classification, nuclear medicine, interventional therapy . Georg Thieme, Stuttgart 2008, ISBN 978-3-1314-3131-8 , p. 43.

[Kessler206-3] Martin Kessler (editor): Small animal oncology: diagnosis and therapy of tumor diseases in dogs and cats . Georg Thieme, Stuttgart, 3rd edition 2012, ISBN 978-3-8304-1137-6 , p. 206.

[4] Werner Paulus, J. Michael Schröder (Ed.): Pathology: Neuropathology . Springer, 3rd edition 2011, ISBN 9783642023248 , p. 526

[5] Roche Lexicon Medicine , 5th edition, Urban & Fischer , Munich and Jena 2003, ISBN 3-437-15156-8 , page 755.

[Kessler207-6] Martin Kessler (editor): Small animal oncology: diagnosis and therapy of tumor diseases in dogs and cats . Georg Thieme, Stuttgart, 3rd edition 2012, ISBN 978-3-8304-1137-6 , p. 207.