In clinical practice, hamartoma in the urethra is extremely rare, especially in the posterior urethra of children. X-ray imaging, color Doppler ultrasound, CT scan, MRI, and voiding cystourethrography (VCUG) are helpful in the diagnosis of this tumor. Most of the tumors are round solid masses, and generally tend to be benign. A surgical resection is the only effective method for the treatment of urethral hamartoma (1). Urethral cystoscopy before a resection is helpful to clarify the location, texture, and size of the tumor, as well as its relationship with the surrounding tissues. Combined with clinical manifestations, the diagnosis of benign tumors can be initially determined, and the final diagnosis depends on the histopathological examination. Here, we report the case of a patient with posterior urethral hamartoma that was recently treated in our department and share our experience in its diagnosis and treatment process.

The operation was successful, and postoperative treatments such as prevention of infection, preventive hemostasis, nutritional rehydration, and dressing change were provided. The results of postoperative pathological examination showed that part of the examined tissues were polypoid hyperplasia, covered by the proliferative squamous epithelium, under which were proliferating fibers, small blood vessels, and smooth muscle, and diffuse infiltration of chronic inflammatory cells (Figures 3A,B). Some tissue was covered with urothelium, and cartilage islands, smooth muscle, blood vessels, and nerves were observed at the broken ends (Figure 3C). One lymph node was found locally, with lymphoid follicular hyperplasia, lymphatic sinus dilatation, and sinus histiocytosis. Combined with the above pathological results, the final diagnosis was hamartoma. The patient was discharged with a catheter, and the catheter was removed 2 weeks after discharge. The parents were informed after the operation. After the child recovered further, he was returned to the hospital for hypospadias repair.

The child was reexamined in the outpatient department of our hospital since early childhood, and through continuous physical examination comparison, it was known that the urethral vegetation continued to grow. We provided this case through relevant diagnosis and treatment and literature analysis of “urethral hamartoma.”

First reported by Albrecht in 1904, “hamartoma” is a tumor-like malformation caused by the wrong combination and arrangement of normal tissues in an organ during development (2). It is often a kind of abnormal development and growth of tissues after birth. This overgrown tissue still has the morphology of mature tissue and does not show the characteristics of tumor tissue, but sometimes it can develop into a tumor. Hamartoma is not a true tumor, and it grows slowly. It can grow with the development and growth of the body, but it automatically stops when it grows to a certain extent. It is more coordinated with the body and has a low malignant transformation rate (3). However, some studies have shown that hamartomas are true tumors [such as renal angiomyolipoma (4)], rather than abnormal combinations of normal tissues, and should be classified as mesenchymal tumors. The most common site of hamartoma is the kidney (5), followed by the lung (6), hypothalamus (7), and liver (8). It rarely occurs in the perineum (9, 10), and it is even rarer in the urethra (11), which has not been reported in China.

The main complaints of the child were the abnormal appearance of the penis and ectopic urethral opening. Since birth, the child was found by his parents to have ectopic urethral opening and a red polyp protruding from the perineal urethral opening, and the protrusion gradually increased with the growth of the child. Whether clinical diagnosis or imaging diagnosis, hamartoma has a high misdiagnosis rate (12). MRI is a useful diagnostic tool. Studies have shown that when a discrete pulmonary nodule shows neither fat nor calcification on CT scan, MRI can detect the very typical split-like structure in pulmonary hamartoma, which can provide a diagnostic basis (13). In this case, the color Doppler ultrasound tended to an “inflammatory granuloma,” the perineal sheet tissue was seen on MRI, and the signal was equal to the surrounding tissue. The enhanced scan showed an obvious uneven enhancement, and the outpatient physical examination tended to “repeated penile deformity” and “lymphangioma.” The causes of misdiagnosis were summarized as follows: first, the clinical cases were rare; second, the appearance of hamartomas does not have obvious characteristics such as cysts, polyps, hemangiomas, and other lesions (14). Throughout the entire perineal physical examination of the patient, it is worth mentioning that this case was based on the deformity of the penis and urethral orifice (perineal hypospadias). Early chromosome examination can further exclude the possibility of abnormal sex development. In this case, both the preoperative VCUG examination and intraoperative cystoscopy exploration showed that the perineal opening of hypospadias was blocked by hamartoma tissue, resulting in a fissure and stenosis of the external urethral orifice, increasing urethral resistance, shortening and narrowing of the normal posterior urethra, and dilatation of the local urethra in a cystic structure. In addition, the root of the neoplasm is suspected to gradually extend to the proximal end of the posterior urethra and approach the verumontanum, which increases the difficulty of a resection during operation.

A complete surgical resection is the only effective treatment for posterior urethral hamartoma. In this case, the mass was completely removed during operation, and the results of the postoperative pathological examination supported the histological diagnosis of hamartoma. Histologically, the main components of hamartoma include mesenchymal tissues such as cartilage, fibrous tissue, adipose tissue, nerve, and blood vessels (15). The proportion of each component is different, and it is usually named after the dominant component, which can be divided into chondroid hamartoma, chondromesenchymal hamartoma, angioid hamartoma, epithelioid hamartoma, etc. (16). The prognosis of hamartoma is good without postoperative radiotherapy or chemotherapy. Up to now, the child has no recurrence, no urethral stricture, and no urinary incontinence and other related symptoms, which makes a good condition for the later repair of hypospadias. In addition, it is worth noting that due to the short follow-up time of this case, a long-term follow-up should be strengthened in combination with the continued diagnosis and treatment of hypospadias in the future. This case report is extremely rare in clinical practice, which can further deepen the understanding of urogenital malformations and tumors in children, provide a certain theoretical basis for clinical diagnosis, and reduce the misdiagnosis rate.

Posterior urethral hamartoma complicated with hypospadias is rare in children, and more clinical practice studies are needed. Before surgery, it is necessary to perform conventional series of examinations such as x-ray imaging, color Doppler ultrasound, CT scan, MRI, and VCUG. Before a formal resection, urethrocystoscopy is needed to further clarify the nature and location of the tumor and the condition of the urethra. During the resection, attention should be paid to reduce the damage of urethral mucosa, so as to minimize the influence on the subsequent urethroplasty. Therefore, in patients with urethral hamartoma, more cases to be observed and a longer-term effective follow-up are needed for verification.