|Year : 2013 | Volume
| Issue : 4 | Page : 275-277
Infarcted paratesticular adenomatoid tumor: A diagnostic challenge
Jayashree Krishnamurthy, Shakuntala C Patil, Manjunath V Gubbanna
Department of Pathology, Jagadguru Sri Shivarathreeshwara Medical College, Mysore, Karnataka, India
|Date of Web Publication||7-Feb-2014|
#1670, 7th cross, Narayan Shastri Road, Mysore - 570 004, Karnataka
Source of Support: None, Conflict of Interest: None
Adenomatoid tumors are regarded as distinctive benign mesothelial neoplasm of the paratesticular region. We present a case report of an adult male who presented with right testicular swelling and pain, which was reported as paratesticular tumor on ultrasound examination. The cut-section of the orchidectomy specimen showed a well-circumscribed nodule with wide areas of necrosis. Microscopically, the lesion was composed of tubules that were lined by flat to cuboidal cells with round to oval nuclei and abundant vacuolated cytoplasm which were diagnostic of adenomatoid tumor. But the associated extensive areas of coagulative necrosis and reactive changes of fibroblasts and myofibroblasts obscured the main lesion and posed diagnostic difficulty. Positivity for calretinin and cytokeratin-7 are useful for confirming the diagnosis. Infarction of an adenomatoid tumor obscures the nature of the underlying lesion and causes diagnostic challenge.
Keywords: Adenomatoid tumor, fibroblasts and myofibroblast, necrosis, paratesticular region, reactive changes
|How to cite this article:|
Krishnamurthy J, Patil SC, Gubbanna MV. Infarcted paratesticular adenomatoid tumor: A diagnostic challenge. Int J Health Allied Sci 2013;2:275-7
|How to cite this URL:|
Krishnamurthy J, Patil SC, Gubbanna MV. Infarcted paratesticular adenomatoid tumor: A diagnostic challenge. Int J Health Allied Sci [serial online] 2013 [cited 2019 Nov 12];2:275-7. Available from: http://www.ijhas.in/text.asp?2013/2/4/275/126750
| Introduction|| |
Adenomatoid tumors are regarded as distinctive benign mesothelial neoplasms and rank second to spermatic cord lipoma as the most common paratesticular tumor.  It was first described in 1945 by Golden et al., as a small firm asymptomatic intrascrotal mass, with no pain or tenderness, occurring in 3 rd 5 th decades of life.  It often involves the epididymis, but may also occur in the spermatic cord and testicular tunics. It occurs over a wide age range, with a median age of 35 years.  The origin of these tumors has been the subject of debate, though recent studies suggest a probable mesothelial origin. 
Grossly, they are often well-circumscribed, firm, white to tan nodules, usually less than 2 cm in diameter. Microscopically, being poorly circumscribed they consists of cuboidal to flattened cells with vacuolated cytoplasm and form solid cords with an epithelial appearance alternating with channels having dilated lumina simulating vascular structures.  Intervening stroma contains abundant smooth muscle and elastic fibers with desmoplastic quality. Paucity of typical adenomatoid tumor with associated wide areas of infarction, the cause of which is speculative obscures the main lesion. The reactive changes may have a microscopic appearance suggestive of a malignant neoplasm, with irregular pseudoinfiltration mimicking an infiltrating carcinoma.  Three kinds of adenomatoid tumor: Plexiform, glandular, and angiomatoid may be discriminated.  Because of its rarity and obscuring nature when associated with infarction, the clinical and histopathological aspects are discussed.
| Case Report|| |
A 70-year-old male presented with right testicular swelling since 15 years and pain since 1 month. On local examination a firm tender swelling was noted in the right testicular region. Ultrasound examination showed a well-defined hypoechoic mass lesion at the upper pole of right testis suggesting a paratesticular tumor, following which a high inguinal orchidectomy was done. Grossly, the specimen measured 19 × 8 × 4 cm and cut-section showed a well-circumscribed grey-white tumor with wide areas of necrosis [Figure 1].
|Figure 1: Cut-section of the high inguinal orchidectomy specimen showing a well-circumscribed grey-white tumor with wide areas of necrosis|
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Microscopically, there was a pseudoencapsulated lesion composed of network of tubules displaying extensive areas of coagulative necrosis. Few tubules at the periphery were lined by flat to cuboidal cells with round to oval nuclei and abundant vacuolated cytoplasm [Figure 2]. Florid reactive fibroblasts and myofibroblasts with plump nuclei and prominent nucleoli were seen surrounding the tubules, obscuring the main lesion [Figure 3]. Mitosis was absent and stroma showed focal areas of hyalinization and lymphoid aggregates. These histological features were diagnostic of adenomatoid tumor.
|Figure 2: Tubules with coagulative necrosis surrounded by tubules lined by cuboidal cells with vacuolated cytoplasm, charateristic of an adenomatoid tumor|
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|Figure 3: Florid reactive fibroblasts and myofibroblasts obscuring the tubules with adenomatoid tumor|
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| Discussion|| |
Paratesticular tumors are uncommon comprising less than 5% of intrascrotal tumors. Epididymal epithelial tumors are a rare subtype of paratesticular tumors with the adenomatoid tumor being most common followed by the papillary cystadenoma and the leiomyoma. These tumors usually arise in the epididymis, and approximately 14% of paratesticular adenomatoid tumors arise from the testicular tunica. Except from epididymis, adenomatoid tumor can be located in spermatic cord, prostate, ejaculatory ducts, and scrotal capes; and in female can be located in uterus, Fallopian tube More Detailss, and ovarian area.  It is proposed that adenomatoid tumors arise from pluripotent mesenchymal cells that differentiate towards submesothelial cells and eventually mesothelial cells. This differentiation is probably induced by the adjacent submesothelial cells. 
Adenomatoid tumors are generally asymptomatic and are found accidentally as painless intrascrotal mass that remain unchanged in size for years. They can be seen in all ages, but are common in 3 rd -4 th decades of life.  In the present case; patient noticed an intrascrotal swelling when he was 55-year-old, but he seeked medical intervention only on developing pain 15 years later, which was probably due to infarction. This presentation simulating epididymitis is similar to the presentation of the two patients described by Skinnider and Young.  Examination of the scrotum reveals a small, well-defined, solid, firm nodular mass; and high-resolution ultrasound is reliable in detecting these lesions. A well-defined hypoechoic mass lesion at the upper pole of right testis on ultrasound examination established the extratesticular location in the present case. They are generally solitary, range in size from 1.1 to 3.5 cm and show areas of necrosis when associated with infarction. 
Adenomatoid tumor has a plethora of microscopic appearances, represented by three basic patterns: Tubules, cords, and small nests, formed of cells that are cuboidal with vacuolated cytoplasm.  Uncommonly, they have accompanying infarction, represented by extensive or focal necrosis with associated reactive changes that impart an appearance that suggests a malignant process.  Adenomatoid tumor associated with infarction was first described by De Klerk et al., and the clinicopathological features of the five cases reported by Skinnider and Young as in the present case posed diagnostic difficulty due to extensive areas of necrosis. , Microscopically, such lesions are characterized by central necrosis with minor amounts of pale mummified, viable adenomatoid tumor identified at least focally but often overshadowed by necrotic tissue. Gaping spaces with no evident lining, representing a necrotic tubular component, and smaller spaces, representing ghost remnants of the typical vacuolar spaces, are major clues to the diagnosis.  Necrosis was surrounded by florid reactive process of fibroblasts and myofibroblasts that had plump nuclei often with prominent nucleoli.  These changes impart an appearance of a malignant process with reactive fibroblastic and myofibroblastic proliferation.  As seen in the present case, the prominent lymphoid aggregates towards the periphery of the neoplasm and absence of mitosis are helpful clues to the diagnosis.  These unemphasized features of adenomatoid tumors may potentially lead to more aggressive therapy than warranted if it is not correctly interpreted. 
The microscopic appearance that often suggests the possibility of a malignant neoplasm include: 1) Blurring of the normal relatively easily identifiable junction between adenomatoid tumor and adjacent tissue; 2) irregular pseudoinfiltration of fat by reactive tissue and adenomatoid tumor; 3) paucity of typical adenomatoid tumor due to the infarction and the fact that viable tumor usually showed a solid pattern; and 4) atypia of the associated reactive cells. 
The differential diagnosis of an infarcted adenomatoid tumor includes malignant mesothelioma, inflammatory myofibroblastic tumor, and inflammatory conditions. Immunoreactive positivity for calretinin and cytokeratin (CK)-7 are useful parameters for establishing a conclusive diagnosis.  Presence of granulation tissue, proliferating fibroblasts, and myofibroblasts admixed with inflammatory infiltrate and a loose myxoid stroma lead to misdiagnoses as an inflammatory myofibroblastic tumor.  However, careful examination of the tumor and specific immunoreactivity will allow identification of solid areas of viable adenomatoid tumor.  Adenomatoid tumor with almost total infarction and a heavy neutrophilic infiltrate may be misdiagnosed as epididymitis. On histological sections, gaping spaces with no evident lining serve as major clues for the diagnosis.  The cause of infarction remains unknown. Skinnider and Young suggested trauma because the majority of tumors were from the epididymis and testis, which are more susceptible to trauma. However, no documented history of trauma has been present in any of the reported cases, including the present case. 
| Conclusion|| |
Based on characteristic gross and microscopic appearance, adenomatoid tumors are easily diagnosed. However, associated infarction may obscure the main lesion and cause diagnostic difficulty. Hence, it is necessary to consider it in the differential diagnosis of tumors associated with necrosis in the genital tract.
| Acknowledgment|| |
Jagadguru Sri Shivarathreeshwara University.
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[Figure 1], [Figure 2], [Figure 3]