IDIOPATHIC
CALCINOSIS
DONALD
T. KING,
STANLEY
BROSMAN,
FRANK
M. HIROSE,
LARRIAN
OF SCROTUM
M.D. M.D. M.D.
M. GILLESPIE,
M.D.
From the Departments of Pathology and Surgery (Division of Urology), Los Angeles County Harbor-UCLA Medical Center, Torrance. California
ABSTRACT - A forty-three-year-old man complained of painless, firm scrotal nodules which had first appeared at age sixteen. These were diagnosed clinically as multiple epidermoid inclusion cysts and were excised. Histologically they were composed of calci$ed, amorphous, granular material, characteristic of idiopathic calcinosis of the scrotum. This is a rare, benign condition without any recognized underlying metabolic abnormalities. The cause of idiopathic calcinosis of the scrotum is unknown, but we believe it is due to dystrophic calcification of dartoic muscles.
Idiopathic calcinosis of the scrotum is an infrequent, benign condition which can be clinically confused with the more common epiderma1 inclusion cyst, often referred to as sebaceous cyst, steatoma, or wen.rs4 It may also be easily mistaken clinically for other benign tumors which include fibromas, lipomas, and myxomas. Less than 50 instances of idiopathic calcinosis of the scrotum have been described, and many of these lack histologic documentation. The nodules are usually multiple and originate in childhood or early adult life, increasing in size and number with age. They are generally painless and asymptomatic, although some patients complain of pruritis, heaviness, or breakdown followed by extrusion of white, chalky material.5 The condition is not associated with hypercalcemia, hyperphosphatemia, or other known metabolic disorders, and similar lesions do not appear on other cutaneous areas. Although the cause remains obscure, we believe that idiopathic calcinosis of the scrotum can originate as dystrophic calcification of the dartoic muscle. The following case report illustrates the clinical findings and the typical histopathologic features of this uncommon entity.
92
Case Report At age sixteen, a white male first noted the appearance of multiple, firm, painless nodules within the scrotal wall. These gradually increased in size but were asymptomatic. They remained intact and did not break down. Because the patient felt embarrassed by the lesions, at age forty-three he requested that they be removed. Physical examination was unremarkable except for approximately 20 firm, nontender nodules within the scrotal wall. These ranged from 1 to 2 cm. in diameter. The overlying scrotal skin was unremarkable. No other cutaneous nodules were identified. Surgical excision was performed under local anesthesia and without complication. The preoperative diagnosis was multiple epidermoid studies inclusion cysts. All routine laboratory including serum calcium, phosphorus, uric acid, and alkaline phosphatase were within normal range. Pathologic findings The segments of scrotal skin and underlying nodules weighed 20 Gm. Roentgenograms of
UROLOGY
/ JULY 1979 / VOLUME
XIV, NUMBER
1
FIGURE 1. (A) Roentgenogram of excised scrotal nodules showing numerous radiopaque masses. (B) Large nodule of darkly basophilic, calcijed material surrounded by foreign-body giant cells and dense fibrosis; adjacent area shows fasciculi of dartoic muscle (D). (C) Small calci$ed foci distributed within a population of dartoic muscles (D). (Hematoxylin and eosin stains, original magni,fcations X 120.)
the specimens demonstrated many radiopaque masses, some of which could not be grossly appreciated from the external surface (Fig. 1A). When incised, the nodules were found to contain chalk white, odorless material which had a doughy consistency. On microscopic examination, the nodules were located in the dermis and composed of calcified, amorphous, granular material which was positive with the Von Kossa calcium stain. There were numerous chronic inflammatory cells as well as foreign body giant cells at the margins of the lesions (Fig. 1B). Epithelial cells, microorganisms, or other cellular elements could not be identified within the amorphous material. Besides the grossly identified large nodules, many additional smaller lesions could be seen microscopically. The manner in which these smaller calcified foci were surrounded by dartoic muscle bundles arranged in a regular pattern, suggested that these areas represented calcified dartoic muscle (Fig. 1C). However, all
UROLOGY
/ JULY1979
/ VOLUMEXIV,
NUMBER1
the small calcified lesions appeared to be at the same stage of development, and in none could smooth muscle be clearly identified. The overlying epidermis of the scrotum was unremarkable. Comment Idiopathic calcinosis of the scrotum is a rare benign disorder whose etiology is unknown. Calcification of epithelial inclusion cysts is one theory which is often invoked.’ Morley and Best6 described calcified scrotal nodules which were lined in some areas by a thin layer of stratified squamous epithelium. Unfortunately, they did not include photomicrographs of these areas. However, the failure of more recent authors,415,7 including ourselves, to find remnants of epithelium or keratinaceous debris within these lesions makes this mode of development unlikely. Brown* observed that nodules of onchocerca in the scrotal wall may calcify and resemble idiopathic calcinosis of the scrotum; but
93
the absence of organisms within the lesions of idiopathic calcinosis of the scrotum and the limited geographic distribution of onchocerciasis make this an implausible explanation. Shapiro et ~1.~ were unable to offer an alternative hypothesis for pathogenesis of this lesion and classified it as a type of idiopathic calcification. Veress and Malik,’ on the other hand, believed that it is a special form of dystrophic calcification, but they did not allude to the type of tissues that were involved. We speculate that this entity results from dystrophic calcification which begins within the smooth muscle fasciculi of dartoic muscle. For example, calcification of degenerating uterine leiomyomata is well recognized.g The main support for our theory is the observation of small calcified foci within clusters of dartoic muscles. However, why the nodules should continue to increase in size or what initial degenerative events cause this calcification to occur, remain enigmas.
94
Torrance, California 90509 (DR.
HIROSE)
References 1. Boyce WH, and Politano VA: Infections and diseases of the scrotum and its contents, in Campbell MF, Harrison JH (Eds.), Urology, 3rd ed., Philadelphia, W. B. Saunders Co., 1970, chap. 16, pp. 624-625. 2.-slandy JP (ed.): Penis and scrotum, in Urology, Oxford, Blackwell. 1976. than. 40. DD. 1088-1089. 3. Roth AA: Kerm&omatb;s cysts of the scrotum, a case report, J. Urol. 52: 86 (1944). 4. Fisher BK, and Dvoretzky I: Idiopathic calcinosis of the scrotum, Arch. Dermatol. 114: 957 (1978). 5. Shapiro L, Platt N, and Torres-Rodriguez VM: Idiopathic calcinosis of the scrotum, ibid. 102: 199 (1970). 6. Morley HV, and Best JW: Multiple calcified cysts of the scrotum, case report, J. Urol. 58: 458 (1947). 7. Veress B, and Malik MOA: Idiopathic scrotal calcinosis, a report of six cases from the Sudan, East Al?. Med. J. 52: 705 (1975). 8. Browne SG: Calcinosis circumscripta of the scrotal wall: the aetiological role of Onchocercn uoluuZus, Br. J. Dermat. 74: 136 (1962). 9. Persaud V, and ArJoon PD: Uterine leiomyoma: incidence of degenerative change and correlation of associated symptoms, Obstet Gynecol. 35: 432 (1970).
UROLOGY
/
JULY 1979
/
VOLUME XIV, NUMBER
1
CALCINOSIS
DONALD
T. KING,
STANLEY
BROSMAN,
FRANK
M. HIROSE,
LARRIAN
OF SCROTUM
M.D. M.D. M.D.
M. GILLESPIE,
M.D.
From the Departments of Pathology and Surgery (Division of Urology), Los Angeles County Harbor-UCLA Medical Center, Torrance. California
ABSTRACT - A forty-three-year-old man complained of painless, firm scrotal nodules which had first appeared at age sixteen. These were diagnosed clinically as multiple epidermoid inclusion cysts and were excised. Histologically they were composed of calci$ed, amorphous, granular material, characteristic of idiopathic calcinosis of the scrotum. This is a rare, benign condition without any recognized underlying metabolic abnormalities. The cause of idiopathic calcinosis of the scrotum is unknown, but we believe it is due to dystrophic calcification of dartoic muscles.
Idiopathic calcinosis of the scrotum is an infrequent, benign condition which can be clinically confused with the more common epiderma1 inclusion cyst, often referred to as sebaceous cyst, steatoma, or wen.rs4 It may also be easily mistaken clinically for other benign tumors which include fibromas, lipomas, and myxomas. Less than 50 instances of idiopathic calcinosis of the scrotum have been described, and many of these lack histologic documentation. The nodules are usually multiple and originate in childhood or early adult life, increasing in size and number with age. They are generally painless and asymptomatic, although some patients complain of pruritis, heaviness, or breakdown followed by extrusion of white, chalky material.5 The condition is not associated with hypercalcemia, hyperphosphatemia, or other known metabolic disorders, and similar lesions do not appear on other cutaneous areas. Although the cause remains obscure, we believe that idiopathic calcinosis of the scrotum can originate as dystrophic calcification of the dartoic muscle. The following case report illustrates the clinical findings and the typical histopathologic features of this uncommon entity.
92
Case Report At age sixteen, a white male first noted the appearance of multiple, firm, painless nodules within the scrotal wall. These gradually increased in size but were asymptomatic. They remained intact and did not break down. Because the patient felt embarrassed by the lesions, at age forty-three he requested that they be removed. Physical examination was unremarkable except for approximately 20 firm, nontender nodules within the scrotal wall. These ranged from 1 to 2 cm. in diameter. The overlying scrotal skin was unremarkable. No other cutaneous nodules were identified. Surgical excision was performed under local anesthesia and without complication. The preoperative diagnosis was multiple epidermoid studies inclusion cysts. All routine laboratory including serum calcium, phosphorus, uric acid, and alkaline phosphatase were within normal range. Pathologic findings The segments of scrotal skin and underlying nodules weighed 20 Gm. Roentgenograms of
UROLOGY
/ JULY 1979 / VOLUME
XIV, NUMBER
1
FIGURE 1. (A) Roentgenogram of excised scrotal nodules showing numerous radiopaque masses. (B) Large nodule of darkly basophilic, calcijed material surrounded by foreign-body giant cells and dense fibrosis; adjacent area shows fasciculi of dartoic muscle (D). (C) Small calci$ed foci distributed within a population of dartoic muscles (D). (Hematoxylin and eosin stains, original magni,fcations X 120.)
the specimens demonstrated many radiopaque masses, some of which could not be grossly appreciated from the external surface (Fig. 1A). When incised, the nodules were found to contain chalk white, odorless material which had a doughy consistency. On microscopic examination, the nodules were located in the dermis and composed of calcified, amorphous, granular material which was positive with the Von Kossa calcium stain. There were numerous chronic inflammatory cells as well as foreign body giant cells at the margins of the lesions (Fig. 1B). Epithelial cells, microorganisms, or other cellular elements could not be identified within the amorphous material. Besides the grossly identified large nodules, many additional smaller lesions could be seen microscopically. The manner in which these smaller calcified foci were surrounded by dartoic muscle bundles arranged in a regular pattern, suggested that these areas represented calcified dartoic muscle (Fig. 1C). However, all
UROLOGY
/ JULY1979
/ VOLUMEXIV,
NUMBER1
the small calcified lesions appeared to be at the same stage of development, and in none could smooth muscle be clearly identified. The overlying epidermis of the scrotum was unremarkable. Comment Idiopathic calcinosis of the scrotum is a rare benign disorder whose etiology is unknown. Calcification of epithelial inclusion cysts is one theory which is often invoked.’ Morley and Best6 described calcified scrotal nodules which were lined in some areas by a thin layer of stratified squamous epithelium. Unfortunately, they did not include photomicrographs of these areas. However, the failure of more recent authors,415,7 including ourselves, to find remnants of epithelium or keratinaceous debris within these lesions makes this mode of development unlikely. Brown* observed that nodules of onchocerca in the scrotal wall may calcify and resemble idiopathic calcinosis of the scrotum; but
93
the absence of organisms within the lesions of idiopathic calcinosis of the scrotum and the limited geographic distribution of onchocerciasis make this an implausible explanation. Shapiro et ~1.~ were unable to offer an alternative hypothesis for pathogenesis of this lesion and classified it as a type of idiopathic calcification. Veress and Malik,’ on the other hand, believed that it is a special form of dystrophic calcification, but they did not allude to the type of tissues that were involved. We speculate that this entity results from dystrophic calcification which begins within the smooth muscle fasciculi of dartoic muscle. For example, calcification of degenerating uterine leiomyomata is well recognized.g The main support for our theory is the observation of small calcified foci within clusters of dartoic muscles. However, why the nodules should continue to increase in size or what initial degenerative events cause this calcification to occur, remain enigmas.
94
Torrance, California 90509 (DR.
HIROSE)
References 1. Boyce WH, and Politano VA: Infections and diseases of the scrotum and its contents, in Campbell MF, Harrison JH (Eds.), Urology, 3rd ed., Philadelphia, W. B. Saunders Co., 1970, chap. 16, pp. 624-625. 2.-slandy JP (ed.): Penis and scrotum, in Urology, Oxford, Blackwell. 1976. than. 40. DD. 1088-1089. 3. Roth AA: Kerm&omatb;s cysts of the scrotum, a case report, J. Urol. 52: 86 (1944). 4. Fisher BK, and Dvoretzky I: Idiopathic calcinosis of the scrotum, Arch. Dermatol. 114: 957 (1978). 5. Shapiro L, Platt N, and Torres-Rodriguez VM: Idiopathic calcinosis of the scrotum, ibid. 102: 199 (1970). 6. Morley HV, and Best JW: Multiple calcified cysts of the scrotum, case report, J. Urol. 58: 458 (1947). 7. Veress B, and Malik MOA: Idiopathic scrotal calcinosis, a report of six cases from the Sudan, East Al?. Med. J. 52: 705 (1975). 8. Browne SG: Calcinosis circumscripta of the scrotal wall: the aetiological role of Onchocercn uoluuZus, Br. J. Dermat. 74: 136 (1962). 9. Persaud V, and ArJoon PD: Uterine leiomyoma: incidence of degenerative change and correlation of associated symptoms, Obstet Gynecol. 35: 432 (1970).
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/
JULY 1979
/
VOLUME XIV, NUMBER
1
