睪丸皮膚血管內乳突狀內皮細胞增生(Masson氏瘤): 案例報告

蔡仕傑¹、張延驊^{1, 2}、黃志賢^{1, 2}

¹臺北榮民總醫院泌尿部；²國立陽明交通大學醫學系泌尿學科及書田泌尿科學研究中心

Intravascular Papillary Endothelial Hyperplasia (Masson Tumor) of Testis: Case Report

Shi-Jie Tsai¹, Yen-Hwa Chang ^{1, 2}, William J.S. Huang^{1, 2}

¹ Department of Urology, Taipei Veterans General Hospital,

²Department of Urology, College of Medicine and Shu-Tien Urological Science Research Center,

National Yang Ming Chiao Tung University, Taipei, Taiwan

Introduction

Intravascular papillary endothelial hyperplasia (IPEH) or Masson tumor is a rare intravascular benign lesion. It may involve a wide variety of organs, most frequently the skin and subcutaneous tissue. Herein we presented a rare case of testicular IPEH treated with surgical resection in our institute.

Care presentation

This 56-year-old male Taiwanese has three children declines having any systemic diseases before. He presented to our clinic due to self-palpable right testicular mass for one month. Physical examination revealed a smooth round nodule at right testis. Doppler ultrasound for scrotum which performed on 2021/05/19 showed a 1.9 cm nodule in the right testis, with internal calcified spots and increased blood flow, in favor of germ cell tumor. Laboratory test of testicular tumor markers showed normal level of beta-HCG (<0.200 mIU/ml), AFP (3.92ng/ml), and LDH (215U/L). Pelvis CT scan on 2021/06/01 demonstrated no retroperitoneal LAPs, a soft tissue nodule at right scrotum with prominent bilateral vascularity of spermatic cords. Surgical intervention was suggested due to concerns of malignancy. Right radical orchiectomy was performed on 2021/07/01. Gross examination of the specimen showed a 1.3 x 1.0 x 0.5 cm brown-reddish colored nodule embedded in the caudal portion of right testis. Microscopically, the nodule was well-defined, and surrounded by muscle layer with intravascular growth of papillary structures and channels lined by endothelial cells. The final pathology reported intravascular papillary endothelial hyperplasia. The post-operative recovery course was uneventful. Follow-up sonography six months after the operation showed no evidence of recurrence.

Discussion

Intravascular papillary endothelial hyperplasia (IPEH) is a rare intravascular benign lesion characterized by excessive proliferation of endothelial cells in normal blood vessels or vascular malformations. It was first described by Pierre Masson in 1923 and is therefore also called Masson tumor ^[1].

IPEH can occurred in any location in the body, most commonly affects the skin of head, neck, fingers and trunk ^[2]. Rare cases of lesions in a variety of locations have been reported in literature, including external jugular vein, kidney, liver, chest wall, and superior vena cava ^[3]. Regarding male genital organs, the incidence is exceedingly rare. Otta et al. once described a paratesticular IPEH in 2018, which was also managed by surgical resection ^[4].

IPEH typically manifests as a palpable mass, with no age preference. Female patients are affected slightly more frequently than male patients ^[5]. Histologically, IPEH appears as papillary projections of a hyalinized fibrous connective tissue core surrounded by a hyperplastic monolayer of endothelial cells ^[6]. On imaging, it is often difficult to differentiate from malignant tumors, and final diagnosis can only be made by histopathological examination. On sonography, IPEH could present as lesions with both venous and arterial flow pattern due to the hypervascular nature of the lesion ^[7]. Such high vascularity features might mimic germ cell tumor if presents at testis.

The pathogenesis of IPEH remains unclear. Secondary factors such as local trauma and pre-existing vascular conditions (hemangiomas, vascular malformations, pyogenic granulomas, blood stasis, etc.) account for 30% of the cases, but in remaining 70%, the triggering stimulus cannot be identified. Excessive endothelial proliferation driven by local production of growth factors has been a promising hypothesis to explain the etiology of IPEH ^[8].

Due to the benign nature of IPEH, treatment depends on the location of the lesion and the symptoms it produces. In general, surgical excision with free resection margin is the treatment of choice, with good prognosis and low relapse rate. We report a case of testicular IPEH that presented a clinical history and imaging exams that resembles malignant tumor. The definite diagnosis could only be made by histopathology. The clinical course of our case seems similar to IPEH of other locations, and no recurrence or local complications was reported after complete tumor resection.

References:

1. Masson P. Hemangioendothelioma vegetant intravasculaire. Bull Soc Anat (Paris) 1923; 93:517–523.
2. Clifford PD, Temple HT, Jorda M, et al. Intravascular papillary endothelial hyperplasia (Masson's tumor) presenting as a triceps mass. Skeletal Radiol 2004; 33: 421.
3. Park JY, Chung-Park M, Snow N. Intravascular papillary endothelial hyperplasia of superior vena cava: a rare cause of the superior vena cava syndrome. Thorax 1991; 46: 272.
4. Otta R, et al. Paratesticular Masson’s Hemangioma Case Report and Review of the Literature. J Urol Nephrol 2018, 3(2): 000141.
5. Hagiwara A, Inoue Y, Shakudo M, et al. Intracranial papillary endothelial hyperplasia: occurrence of a case after surgery and radiosurgery. J Comp Assisted Tomography 1999; 23:781–785.
6. Sarode, G.S., et al. “Oral intravascular papillary endothelial hyperplasia (Masson’s tumor): A review of literature.“J Oral Maxillofac Surg Med Pathol. 26.1 (2014):73-79.
7. Lysyy O, Schwartz I, Kolander Y, Strauss S. Sonographic features of intravascular papillary endothelial hyperplasia (Masson's tumor) in the forearm. J Clin Ultrasound. 2011 Jun;39(5):301-3.
8. Cagli S, Oktar N, Dalbasti T, Işlekel S, Demirtaş E, Ozdamar N. Intravascular papillary endothelial hyperplasia of the central nervous system--four case reports. Neurol Med Chir (Tokyo) 2004; 44:302–310.