Testis & paratestis
Epididymal tumors
Adenocarcinoma of epididymis
Author: Swapnil U. Rane, M.D.
Last author update: 1 October 2014
Last staff update: 28 March 2022
Copyright: 2003-2024, PathologyOutlines.com, Inc.
PubMed Search: Adenocarcinoma [title] testis
Table of Contents
Definition / general | Terminology | Epidemiology | Sites | Pathophysiology | Clinical features | Diagnosis | Laboratory | Prognostic factors | Case reports | Treatment | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Differential diagnosisCite this page: Rane S. Adenocarcinoma of epididymis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/testisepidadenocarcinoma.html. Accessed April 18th, 2024.
Definition / general
- Adenocarcinoma arising de novo in epididymis
Terminology
- Also called papillary adenocarcinoma, cystadenocarcinoma, papillary cystadenocarcinoma
Epidemiology
- Extremely rare
- Age range: 27 - 82 years, mean age: 67 years
Sites
- Tumors are centered on epididymis; may be confined to epididymis or may infiltrate adjacent tissue
Pathophysiology
- Believed to arise from metaplastic epididymal epithelium
Clinical features
- Usually presents as palpable scrotal mass with / without pain and hydrocele
Diagnosis
- Confirmation and differentiation from other malignancies in this region is possible only on histology
Laboratory
- No specific laboratory features
- Negative serum markers for sex cord and germ cell tumors
Prognostic factors
- Due to rarity of tumor, prognostic features are unknown
- A large proportion of tumors reported in literature metastasize at presentation or later
Case reports
- 27 year old man with papillary cystadenocarcinoma of epididymis (Zhonghua Yi Xue Za Zhi (Taipei) 1990;45:139)
- 35 year old man with radiotherapy treatment for epididymal adenocarcinoma (Onkologie 2012;35:43)
- 62 year old man (Urology 1998;52:904)
- 82 year old man with papillary adenocarcinoma of epididymis (Acta Pathol Jpn 1993;43:440)
- Papillary cystadenocarcinoma of epididymis presenting with scrotal mass (J Urol 1992;147:162)
- Carcinoma of epididymis (Indian J Cancer 1973;10:475)
- Adenocarcinoma of the epididymis - 4 cases (Am J Surg Pathol 1997;21:1474)
- Primary adenocarcinoma of epididymis (Int Urol Nephrol 2004;36:77)
Treatment
- High inguinal orchidectomy with retroperitoneal lymph node dissection
- Adjuvant chemotherapy or radiation therapy
Gross description
- 1 - 7 cm
- Infiltrative tumor either confined to epididymis or infiltrating adjacent soft tissue
- Tan to grey white cut surface with frequent foci of hemorrhage and necrosis
Microscopic (histologic) description
- Tubular, tubulopapillary, papillary and cystic growth patterns, which often occur in combinations and varying degrees of complexity
- Also an undifferentiated sheet like pattern
- Tumor cells are cuboidal to columnar, predominantly clear, rich in glycogen
- Often infiltrates into epididymal smooth muscle or adjacent soft tissue
- Necrosis is usually present
- Psammoma bodies are rare
Microscopic (histologic) images
Images hosted on other servers:
Adenocarcinoma of rete testis
Differential diagnosis
- Other primary tumors of epididymis and paratesticular region
- Adenomatoid tumor
- Usually lack clear cells
- Tubules lined by low cuboidal to flat cells which may be vacuolated but are not watery clear as seen in primary epididymal adenocarcinoma
- Low grade nuclear features
- Mesothelial origin
- IHC for mesothelial markers usually positive
- Carcinoma of rete testis
- Centered on testicular hilum, associated with transition to normal rete testis
- Elongated tubular pattern, unlike the round tubular pattern of epididymal adenocarcinomas
- Mesothelioma
- No clear cells
- Calretinin, HBME1, WT1, mesothelin positive
- Serous cystadenoma of epididymis
- Lack of invasive features
- Low grade cellular features
- Associated with von Hippel-Lindau syndrome
- Serous papillary carcinoma: infiltrates as single isolated papillae, no tubules
- Adenomatoid tumor
- Metastatic prostatic carcinoma: PSA+
- Metastatic GI adenocarcinoma: CEA+, CK20+; variable mucin
