Microlithiasis in the testis can be histological or radiological microcalification. They are not essentially the same entity. Of interest to the urologist however is the radiologically detected micolithiasis.
Oiye was the first to describe intratesticular calicifications in 6 of 192 testicles in autopsy specimens as early as1928 [14]. This report was followed a year later by Blumensaat, who reported similar intratubular bodies in postmortem specimens [15]. He felt they were degenerated spermatogonia displaced into the lumen of the seminiferous tubules. Later Bigger and Mc Adams using various histo-chemical techniques found that the laminated eosinophilic material was a glycoprotein derived from intra tubular secretions, which later calcified [16]. But it was not until 1961 that Azzopardi & Mostofi [17] from the Armed forces institute of Pathology in Washington described the two different types of intra-testicular calcification and their associated pathology. They reported the more commonly found rounded laminated intra tubular calicifications associated with cryptorchid testis, adenomatous or inflammatory pathology. They then reported the amorphous haematoxylin staining calcific bodies in dilated seminiferous tubules found in 13 of 17 patients with wide spread chorio-carcinoma. Histo-chemical methods showed them to consist of phospholipid, protein debris, DNA and calcium phosphate. These calcifications were seen in close association with malignant neoplastic cells.
Diffuse microcalcification in the testis on a plain X ray film was first reported by Priebe & Garret in a 4 year old boy with an otherwise normal testicle in 1970 [18]. But it was not until the mid 80 s when Doherty et al using a 10- MHz transducer first described ultra sonically detected testicular microlithiasis [1]. Ever since, the interest in this entity has increased, with several case reports and retrospective studies reporting an association with testicular cancer [2–8]. However these studies were either isolated case reports or retrospective studies in selected group of patients.
In one series of 263 sub-fertile men, 20% were found to have microlithiasis [12]. In the same study 20% of the men with bilateral microlithiasis were found to have CIS. Interestingly there was no association of CIS with unilateral microlithiasis in this study group. In another series of patients with testicular germ cell tumour Skakkabaek found a significant association of contra-lateral testicular microlithiasis and CIS [13]. Clearly in the high-risk group (described earlier) there seems be a significant association of testicular microlithiasis and CIS, which needs to be clarified with further longitudinal studies.
In an ultrasound screening study involving 1504 men between 18 to 35 years from the US army officer corps, Peterson & Costabile R A. [9] found the prevalence of testicular microlithiasis to be 5.6%. In this study African Americans were found to have a higher prevalence of 14% as opposed to whites who had a prevalence of 4%. However the incidence of testicular tumour is higher in whites than African Americans. Analysis of the geographical distribution of these cases showed a negative correlation with the incidence of testicular tumour in the United States. Interestingly there was an association with STD in the regions where testicular microlithiasis had a higher prevalence in this study. In their follow-up report after more than 4 years presented at the AUA meeting in 2004 at San Francisco, USA, they have not had a single case of testicular tumour in their study subjects with testicular microlithiasis.
Our survey confirms that many urologists tend to follow this patient group for a considerable period of time. However there seems to be a considerable variation in the surveillance policy. This is likely to have an enormous bearing on the cost conscious NHS practice in future. The estimated cost in the United States to follow-up all patients with microlithiasis between 18-to 35 years old are about 18-billion dollars per year [10]. It is also known from many studies that there is an average delay of 3–6 months between noticing a testicular lump and seeking medical advice without significantly affecting cure. With the cure rate for testicular cancer exceeding 90%, it is debatable whether an earlier ultrasound diagnosis will have any effect on the outcome than self examination.
With the emerging evidence it seems safe not to routinely follow-up patients who are incidentally diagnosed with testicular microilithiasis [9–11]. They should however be advised to continue testicular self-examination. The importance of testicular microlithiasis in the high-risk groups is not clear and needs further evidence. Until such time it would be logical to follow-up all patients in the high risk group.
We do acknowledge that the response rate to our questionnaire survey has been moderate, with only 57% returns. This has a small chance of bias towards urologists actively following microlithiasis returning the questionnaire, than those who are not keen on following them. However this is more likely to be due to the fact that the questionnaire was sent during school term holidays, when many urologists tend to be on annual leave. The returns were also fairly evenly distributed throughout the UK.
