KA, 69 yo male, complaining of back pain, with recent urinary retention, gait problems. MRI discloses an extradural mass compressing the medulla.

KA, patient de 69 ans admis pour compression mdullaire D4-D5. Plainte depuis 1 an de dorsalgie interscapulaire s'tendant aux deux membres infrieurs sans territoire radiculaire prcis avec des zones de paresthsies. Troubles sphinctriens et de la marche rcents.

L'IRM dorsale montre un processus occupant de l'espace extradural en regard de D4-D5 postro-latral gauche comprimant la moelle, et sortant par le trou de conjugaison correspondant.

Sections show an angiomatous pattern, with areas of hemorrhage.

The capillary structures are lined by plump cells, with mitotic figures, and have papillary features in some areas

Some papillary fronds have a concentric hyaline core. Areas of hemorhage, show a fibrinous meshwork marking the transition with the capillary structures.

At low power, some fragments of the submitted material, are lined peripherally by large vessels.

In some of these vessels, papillary structures are found, on deeper sections Trichrome stained.

Higher magnifications of the previous field.

DIAGNOSIS:

Papillary endothelial hyperplasia in a probable angioma.

Intravascular papillary endothelial hyperplasia is probably not a true neoplasm but is presented here because of capacity to simulate microscopically benign and malignant vascular tumors. First described by Masson in hemorrhoidal vessels as "vegetant intravascular hemangioendothelioma", it is currently thought to represent an exuberant, organization and recanalization of a thrombus, an interpretation supported by immummohistochemical studies. It occurs in previously normal vessels or in varices, hemorrhoids, hematomas, pyogenic granulomas, hemangiomas, and angiosarcomas. The de novo ("pure") form is usually found in the extremities (particularly the fingers) and the head and neck region, whereas the type engrafted or pre-existing vascular disorder ("mixed") tends to be in the trunk. It simulates angiosarcoma because of the presence of papillary formations, anastomosing vascular channels, plump endothelial cells. It is identified because of the exclusively intravascular nature of the process, the lack of necrose bizarre cells, and atypical mitoses; the characteristically fibrinous and/or hyaline appearance of the papillary stalks; and frequent finding of residual organizing thrombi.

(Ref. Ackerman's surgical pathology, 8th ed.)

The litterature about papillary endothelial hyperplasia in the nervous system:

Neurosurgery 1999 Dec;45(6):1478-80

Intravascular papillary endothelial hyperplasia causing cauda equina compression: case report.
Taricco MA, Vieira JO Jr, Machado AG, Ito FY
Department of Neurosurgery, University of Sao Paulo School of Medicine, Clinics
Hospital, SP, Brazil.


OBJECTIVE AND IMPORTANCE: Intravascular papillary endothelial hyperplasia (Masson's vegetant hemangioendothelioma) is a rare condition affecting the neuraxis. In the literature, only one case of this lesion involving the vertebral canal with spinal cord compression has been reported. We present a case of cauda equina compression due to this abnormality.
CLINICAL PRESENTATION:
A 17-year-old boy was admitted at our hospital with pain, numbness, paresis of the left lower extremity, and bladder dysfunction of approximately 1 month's duration. Computed tomography and magnetic resonance imaging of the spine revealed a tumor within the spinal canal at the T12-L1 level.
INTERVENTION: The patient underwent a T12-L1 laminectomy. An epidural red nodular tumor was visualized and totally resected. The findings of the pathological examination were compatible with intravascular papillary endothelial hyperplasia. At follow-up examination 1 month after the operation, the patient had complete resolution of the pain, and the motor deficit and bladder dysfunction had improved significantly.

CONCLUSION: This rare benign vascular lesion may be clinically and histopathologically mistaken for an angiosarcoma. Because the intravascular papillary endothelial hyperplasia can be cured by complete surgical resection, it is important to distinguish between these two lesions to avoid inappropriate aggressive treatment.

J Comput Assist Tomogr 1999 Sep-Oct;23(5):781-5

Intracranial papillary endothelial hyperplasia: occurrence of a case after surgery and radiosurgery.
Hagiwara A, Inoue Y, Shakudo M, Wakasa K, Sato K, Ohata K, Daikokuya H, Yamada
Department of Radiology, Osaka City University Medical School, Japan.

Papillary endothelial hyperplasia (PEH) is considered a form of endothelial proliferation rather than a true neoplasm and is usually located in the skin or subcutis. We report a case of intracranial PEH that occurred after surgery for glioma and subsequent radiosurgery. CT and MR revealed an enhancing extra-axial mass located left posterolateral to the brainstem. Intracranial PEH is rare; to our knowledge, development of an intracranial PEH after surgery and radiosurgery has not been previously reported.



Acta Neurochir (Wien) 1997;139(9):883-6

Multiple intracerebral intravascular papillary endothelial hyperplasia.
Duong DH, Scoones DJ, Bates D, Sengupta RP
Department of Neurological Surgery, George Washington University Medical Center,
Washington, DC, USA.

Intravascular papillary endothelial hyperplasia (IPEH) is a rare benign reactive lesion usually found in thrombosed subcutaneous blood vessels. It uncommonly occurs in the central nervous system and may be mistaken for a more malignant type of tumour such as angiosarcoma. We present a first case of multiple IPEH occurring intracranially in a 51-year-old woman. She developed neurological compromises secondary to the mass affect of the haematoma arising from one of the lesions. Prompt surgical evacuation of the haematoma stabilized her condition. Surgical treatment, pathological findings, radiographic characteristics, and a review of the literature are presented.

J Neurosurg 1997 Mar;86(3):558-63

Intravascular papillary endothelial hyperplasia of the sellar region. Report of three cases and review of the literature.
Kristof RA, Van Roost D, Wolf HK, Schramm J
Department of Neurosurgery and Neuropathology, University of Bonn, Germany.

Intravascular papillary endothelial hyperplasia (IPEH) is considered a reactive proliferation of endothelium associated with thrombosis. The occurrence of IPEH in the cranial cavity is exceedingly rare. In this article, the authors report three cases of IPEH that originated from the cavernous sinus and extended into the sellar contents. The lesions were resected incompletely in two cases and completely in one case. The IPEH in one of the patients was incompletely resected and exhibited further growth on magnetic resonance imaging 3 months postoperatively; local radiation therapy was instituted. This led to shrinkage of the lesion over an additional follow-up period of 3.5 years. In a review of the literature, the authors located seven other cases of intracranial IPEH. The authors conclude that clinically symptomatic intracranial IPEH should be completely resected whenever possible, because it can cause considerable morbidity and mortality and because it is prone to progression or recurrence.