Introduction
Scrotal calcinosis is a rare condition characterized by the presence of multiple, asymptomatic calcified nodules on the scrotal skin, which arises insidiously.(1,2) There has been debate surrounding the pathogenesis and aetiology of scrotal calcinosis with two proposed theories. Some researchers believe that the condition is idiopathic due to the absence of any tissue injury or systemic metabolic disease. However, there is evidence to suggest that the condition stems from the presence of other scrotal structures, particularly, epidermal inclusion cysts and the rupture or degeneration thereof, leading to dystrophic calcification.(1,2) Regardless of origin, the condition is generally benign but warrants surgical removal. Post-operative results are generally good with a low incidence of recurrence.(1–4)
Case Report
A 30-year-old male patient was referred to our outpatient department with a 10-year history of painless, nodular growths on the scrotal skin. He had no known comorbidities. His medical and surgical history was unremarkable with no previous trauma to the genital region. The patient reported that the lesions had progressively increased in size and number since onset but were otherwise asymptomatic. General clinical examination was unremarkable. Multiple diffuse, discrete scrotal nodular lesions ranging in size from 1 to 15 mm (Figure 1A) were found to spread diffusely over the scrotum. They were yellow to light brown in colour and firm and non-tender on palpation. There was no ulceration or erythema of the overlying skin or discharge noted from any of the lesions. There was no extension to the shaft of the penis or surrounding anatomy. No other cutaneous lesions were noted.
A. Clinical photograph demonstrating multiple scrotal lesions. B. Discrete areas of hyper-density on plain film abdominal X-ray, demonstrating calcific deposits in the lesions. C. Post-operative (scrotectomy) result.
Laboratory work-up revealed no evidence of systemic illness. In particular, serum calcium, phosphate and parathyroid hormone levels were all within normal limits. Plain-film X-rays of the abdomen and genital region showed multiple areas of discrete hyper-density corresponding with the position of the scrotal lesions (Figure 1B), indicating calcific deposition.
Surgical excision was the treatment of choice. Care was taken to excise the lesions in their entirety and to include the surrounding scrotal skin. The post-operative course was unremarkable, and a cosmetically acceptable result was achieved (Figure 1C).
Macroscopy of the excised specimen submitted for pathological evaluation revealed skin measuring 95 × 75 mm, with the underlying subcutaneous tissue measuring 80 × 70 × 5 mm. Multiple flesh-coloured nodules of varying sizes were noted on the skin surface; the largest of which measured 15 × 13 × 8 mm and the smallest of which measured 3 × 2 × 1 mm (Figure 2A). On section of the nodules, the cut surface had a chalk-like appearance.
A. Excised skin segment with multiple nodules, following complete surgical excision. This macro-photograph demonstrates multiple nodules of varying sizes, noted on the skin surface. B. Low-power photomicrograph shows large deposits of calcium within the dermis (arrows). (H&E, 2-µm section; original magnification: 20×.) C. A large dermal-based calcium deposit is identified. (H&E, 2-µm section; original magnification: 20×.) D. A foreign-body giant cell reaction is seen at the periphery of the calcium deposit (arrow). (H&E, 2-µm section; original magnification: 100×.) E. A focus of dystrophic calcification is identified (star), and a foreign-body giant cell response to ingested calcium deposits is seen (arrow). (H&E, 2-µm section; original magnification: 400×.)
Microscopy demonstrated skin inclusive of epidermis and dermis. The epidermis showed compact orthokeratosis. Large basophilic deposits of calcium salt were noted within the dermis (Figure 2B and C). In areas, a foreign-body giant cell response was visualized at the periphery of the basophilic deposits. In addition, scattered foci of psammomatous-type calcification were observed (Figure 2E). There was no evidence of an epidermoid lining of epithelium surrounding the calcified deposits. A von Kossa stain was positive in the dermal-based calcium deposits. There was no recurrence noted at subsequent follow-up.
Discussion
Scrotal calcinosis has been described in the literature from as early as the 1800s. The condition is most notable in men between the ages of 20 and 40 years.(1) There appears to be no associated systemic comorbidity in the majority of cases, and the manifestation is relatively insidious and asymptomatic. Patients tend to present only once the lesions have become significant enough to cause discomfort or grown to the extent where they are cosmetically unacceptable for the patient.
Calcinosis cutis is the name given to a group of disorders characterized by the deposition of insoluble calcium salts in the skin and subcutaneous tissues. There are two subtypes of scrotal calcinosis; idiopathic and dystrophic, depending on the aetiology. Dystrophic calcinosis cutis is the more common subtype, most often the result of previous tissue injury from trauma or other inflammatory processes. It is relatively common in the setting of connective tissue disorders and other systemic inflammatory conditions. The important aspect of this subtype of calcinosis cutis is to be alert to other features of a systemic disorder.(1–5)
In our case, there appeared to be a lack of histological features to support the presence of pre-existing scrotal structures such as epidermal cysts or eccrine cysts. Microscopically, an epidermal inclusion cyst demonstrates a cyst lined by stratified squamous keratinized epithelium which may contain desquamated squamous cells within the lumen. The dermal-based nodules showed basophilic calcium deposits. Several reports have described evidence of foreign-body-type granulomatous reactions on histological evaluation,(1) which was validated in this case. Foci of psammomatous-type dystrophic calcification were also noted in this patient.
Surgical management remains the treatment of choice and generally has excellent outcomes. However, in the cases where numerous, large lesions are found diffusely located over the scrotum, tissue coverage post-excision may be a consideration. One option would be to use thigh pedicle flaps from the anterior thigh to create a neo-scrotum. This has been done with some success in several cases.(5) Use of a tissue expander prior to excision is an alternative option.
Recurrence would be of significant concern in the cases where the calcinosis is as a result of ruptured epidermal cysts. Most cases report no recurrence during follow-up.(1) There are reports of multiple episodes of recurrence in some cases,(4) but this appears to be uncommon. Surgical margins are therefore important. It is suggested that recurrence is possible as a result of smaller, micronodules that have been overlooked on initial resection and have continued to grow in size.(6,7)
Conclusion
Idiopathic scrotal calcinosis is a benign condition, and the aetiology is still incompletely understood. However, the condition can be well managed by simple surgical excision. Pre-and post-operative patient counselling are important aspects of management. Histopathological analysis is essential to confirm the diagnosis and exclude other more serious conditions. Post-operative outcomes are usually good, and the rate of recurrence following excision is generally low.