ABSTRACT
The penis is an uncommon site of metastasis, and about 300 cases have been reported worldwide. In order of frequency the primary sites of metastatic penile tumors are the urinary bladder (34.7%), prostate (29.8%), rectum and sigmoid colon (15.7%), and kidney (6.5%). Nearly 50 cases of penile metastasis with varied clinical features from rectal or sigmoid malignancy have been reported. Sagar et al. reported the second case of metastatic malignant melanoma secondary to the penis in 1992. Three and two-thirds of all penile metastasis are metachronus, and about 90% of the reported cases of penile metastasis are part of widespread disease.
We report a case of painful penile metastasis as a manifestation of malignant melanoma of the rectum, which was a disseminated disease.
Mufti Mahmood Ahmad, Iqbal Saleem, Asim Laharwal, Zahid Mohd Rather, Pervaz Ahmad, Waseem Raja, Irshad Ahmad lone, Sajad Parad
Government Medical College Srinagar, Jammu and Kashmir, Srinagar, India
Submitted September 20, 2013 - Accepted for Publication October 24, 2013
KEYWORDS: Malignant melanoma, rectum, metastasis, priapism
CORRESPONDENCE: Mufti Mahmood Ahmad, M.Ch Urology, Government Medical College Srinagar, Jammu and Kashmir, Srinagar, India
CITATION: UroToday Int J. 2013 October;6(5):art 65. http://dx.doi.org/10.3834/uij.1944-5784.2013.10.12
INTRODUCTION
The penis is an uncommon site of metastasis, and about 300 cases have been reported worldwide [1]. In order of frequency the primary sites of metastatic penile tumors are the urinary bladder (34.7%), prostate (29.8%), rectum and sigmoid colon (15.7%), and kidney (6.5%). Nearly 50 cases of penile metastasis with varied clinical features from rectal or sigmoid malignancy have been reported [1,2]. Sagar et al. reported the second case of metastatic malignant melanoma secondary to the penis in 1992. Three and two-thirds of all penile metastasis are metachronus, and about 90% of the reported cases of penile metastasis are part of widespread disease [3,4].
We report a case of painful penile metastasis as a manifestation of malignant melanoma of the rectum, which was a disseminated disease (Figure 1).
CASE REPORT
A 67-year-old Kashmiri male was complaining of a painful persistent erection for 2 weeks with an inability to pass urine for 1 day. On examination, the patient was pale and emaciated with a palpable lower abdominal midline swelling, confirmed to be a full urinary bladder due to an acute retention of urine. Bilateral inguinal lymphadenopathy was present, the shaft of the penis was tender to the touch, and there were multiple hard nodules at the base of the phallus (Figure 2, Figure 3, and Figure 4).
Suprapubic cystostomy was contemplated to relieve the patient of urine retention. Comprehensive review of the records of the patient revealed that the patient was a diagnosed case of malignant melanoma of the rectum with widespread metastasis to the liver and lungs about 8 months back (Figure 5). The patient had refused to receive chemo radiotherapy for the same.
The penile color Doppler showed lymphatic stasis with bilateral inguinal lymphadenopathy and multiple small nodules at the base of the penis. Fine-needle aspiration cytology of the lymph nodes and the penile nodules was done and the features were consistent with metastatic deposits of malignant melanoma. In view of the advanced nature of the disease and the poor performance score of the patient, no surgical intervention was done, and instead the patient was registered with the medical oncology department where he refused to go for any further treatment. The patient expired within 1 month due to septicemia.
DISCUSSION
The penis is a rare site for metastasis despite rich vascularization. Various mechanisms for penile metastasis have been suggested. These include retrograde venous spread, retrograde lymphatic spread, arterial embolism, and local direct extension [4]. Retrograde lymphatic spread into the penile lymphatic channels after obstruction of inguinal and hypogastric nodes seem to be the most plausible theory in our case.
Presenting signs and symptoms in the order of frequency are malignant priapism (40%), urinary retention, penile nodules, ulceration, perineal pain, edema, dysuria and hematuria [1].
Eighty percent of the cases are due to advanced stages of initial neoplasm and generally have a very poor prognosis [5]. The most frequent primary tumor corresponded to the genitourinary area and makes up approximately 70% of the total cases [6]. Twenty-two percent of all the metastasis to the penis originates in the gastrointestinal tract, particularly the sigmoid colon and the rectum (16%) [5].
Management of penile metastasis is mainly palliative, as it usually represents a part of advanced disease. Management is influenced by the size of the primary extent of the metastatic spread, the general condition of the patient, and also prognostic features of the primary tumor. Treatment varies widely depending on case characteristics, and options are chemotherapy, radiotherapy, cavernosum/spongiosum short circuit, urinary tract diversion through cystostomy, and partial or total phallectomy [8]. Prognosis is invariably poor, with a 5 to 22 month survival rate for colorectal tumors [9].
To the best of our knowledge this is the first ever case of malignant melanoma arising from gastrointestinal tract metastasizing to the penis and presenting as priapism.
CONCLUSION
Metastasis to the penis from a tumor of the rectum is very rare, with about 50 cases reported to date, none of them being malignant melanoma histologically. We report the first such case. The prognosis is very poor and proper treatment modality needs to be charted out.
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