Intravascular papillary endothelial hyperplasia

Intravascular papillary endothelial hyperplasia, regarding a case

INTRODUCTION

Intravascular papillary endothelial hyperplasia (IPEH) was first described as a malignant lesion by Pierre Masson in 1923⁽¹⁾, warning his histological similarity to angiosarcoma. Later, Henschen⁽²⁾ described an intravascular endothelial proliferation that he interpreted like a reagent process due to inflammation and stasis vascular.

We present a case of a patient diagnosed with intravascular papillary endothelial hyperplasia in renal vein.

CASE REPORT

61 years old male referred to our department with symptoms compatible with right renal colic. He has previous history of hypertension, obstructive sleep apnea syndrome and benign prostatic hyperplasia with alpha-blocker therapy.

The patient relates intense pain in the right flank, sometimes radiating to ipsilateral inguinal region. On physical examination revealed pain with percussion in the right flank. Blood and urine analysis, abdominal radiography and ultrasound are requested, all of them normal. Due to the persistence of symptoms, CT scan with contrast was requested (Fig. 1), in which a solid mass of 3.5 x 3 x 4 cm, lobulated and with heterogeneous necrotic center located at the right renal hilum infiltrates renal vein is seen . This mass is adjacent to lower portion of adrenal gland, kidney, and posterior portion of the duodenum, not clearly identifying dependency. To try to understand the dependence of this mass MRI is requested (Fig. 2), which describes hypointense on T1 and hyperintense on T2 tumor, with probable adrenal gland dependence.

Suspecting adrenal injury, hormonal and metabolic study is carried on in blood and urine of 24 hours, all was normal. Scintigraphy was also performed with MIBG finding no enhancing lesions.

Given previous findings, and the likelihood of adrenal malignancy (nonfunctional), surgery is decided. By a subcostal laparotomy, a tumor about 4 cm, firmly adhered to the renal hilum is observed. Right radical nephrectomy is performed due to impossibility the tumor excision alone.

Postoperative course without incidences and the patient was discharged on the fourth day.

Microscopic examination of the surgical specimen revealed kidney and adrenal gland unaltered. Near of the renal hilum and, at least partially, contained within a dilated vein, thrombosis and endothelial reactive area proliferation (capillary and papillary), compatible with papillary endothelial hyperplasia intravascular (Fig 3).

Currently the patient is reviewed every six months, with analytical tests and CT normal.

DISCUSSION

Enzinger and Clearkin⁽³⁾ suggested several morphological features that served in the differential diagnosis between IPEH and angiosarcoma, including intraluminal location of the lesion, absence of necrotic tissue and presence of thrombotic material, and proposed the intravascular papillary endothelial hyperplasia term.

The etiology of IPEH is still unknown. Trauma has been proposed as the main etiological factor, but the traumatic history is exceptional. Several authors agree with the view of Clearkin and Salyer who believe it is due to an alteration in the thrombosis process, consisting of an unusual and peculiar way of organizing thrombus.^{( 3,6 )}

IPEH can occur at any age, more frequently in female. Most of the cases are localized to skin vessels, in head and neck, where they appear as small hard mass of bluish red coloration to the skin. Although there have also been less frequent locations as jejunum, central nervous system, liver, and lungs ^(4,5).

Three forms have been described: Primary, on dilated vascular lakes; secondary or mixed, with preexisting vascular lesion as hemangioma , arteriovenous malformations or pyogenic granuloma; and the third and less frequent, extravascular, resulting in a hematoma ⁽⁷⁾.

The finding of IPEH in the renal vein is rare, there are very few cases reflected in the literature. The symptoms are variable, ranging from an incidental finding, asymptomatic, to colic pain and hematuria.

In imaging, with the CT scan with contrast we can find a solid lesion with heterogeneous contrast enhancement, and in MRI a lesion hypointense on T1 and hyperintense on T2 , which does not exclude malignancy^{(8, 9)}.

In a case reported⁽¹⁰⁾, preoperative diagnosis was performed with excision of the lesion and kidney preservation. But in most cases, it was impossible to rule out malignancy, and the radical surgery is usual, either for technic impossibility by proximity to the renal vessels, or the suspicion of malignancy. No metastases or malignant degeneration has been reported.

Preoperative diagnosis of IPEH is difficult as there are no characteristic symptoms or an imaging test that allows adequate differential diagnosis.

There are several neoplastic and non-neoplastic lesions that can be found in the renal hilum. Among them: renal carcinoma, angiomyolipoma , schwannoma , myelolipoma , hemangiopericytoma , lymphoma, cysts, Castleman disease or lipomas.

Therefore, this condition, although rare, must fall within the diagnostic possibilities, especially if their dependency or proximity to vessels is detected.

CONFLICT OF INTEREST

The authors declare no conflict of interest

REFERENCES

1. Masson P. Hemangioendothelioma vegetant intra-vasculaire. Bull Soc Anat Paris 1923;93:517–23.

1. Henschen F. L´endovasculite proliferante thrombopoietique dans la lesion vasculaire locale. Ann anat Pathol 1932;9:113-21.

1. Clearkin KP, Enzinger FM. Intravascular papillary endotelial hiperplasia. ARch Pathol Lab MEd 1976;10:441-4.

1. Johraku A, Miyanaga N, Sekido N, et al. A case of Intravascular Papillary Endothelial Hyperplasia Arising from Renal sinus.Jpn J clin Oncol 1997; 27(6) 433-36.

1. Pelosi G, Sonzogni A, VIale G. Intravascular Papillary Endothelial Hyperplasia of the renal vein. Int J Surg Pathol 19(4) 518-20

1. Salyer WR, Salyer DC. Intravascular angiomatosis: development and distinction from agniosarcoma. Cancer. 1975; 36: 995-1001

1. Hashimoto H, Daimaru Y, Enjoji M. Intravascular papillary endothelial hyperplasia. A clinicopathological study of 91 cases. AM J Dermatopathol. 1983; 5:539-46

1. Kuo T, Sayers CP, Rosai J. Masson´s `Vegetant intravascular hemangioendothelioma´: a lesion often mistaken for angiosarcoma. Cancer 1976; 38: 1227-36.

1. Van den bogaert S, Boel K, Van Poppel H, et al. Masson´s tumour of the kidney. Cancer Imaging. 2002; 2: 116-9.

1. Akhtar M, Aslam MAL-Mana H, et al. Intravascular Papillary endothelial Hyperpasia of Renal Vein. Arch Pathol Lab med. 2005;129: 516-520

LEGENDS TO FIGURES

Fig.1CT: heterogeneous mass with necrotic core located in the right renal hilum.

Fig. 2 T1-weighted MR image: hypointense mass on the right renal hilum.

Fig. 3 Histological specimen. Close to the renal vascular pole and partially including a dilated vein, an intravascular thrombus and a reactive endothelial proliferation zone (capillary and papillaroid) are observed.

Fig. 4 Greater magnification of the previous image, which can be seen proliferation of papillary structures that tend to anastomose that are lined by a row of endothelial cells, centered on an axis of collagen and fibrin. No images of necrosis, atypia or mitosis (not characteristic of malignancy) were observed.