Testis and epididymis
Other tumors not specific to testis
Interdigitating dendritic cell tumor

Author: Jennifer Gordetsky, M.D. (see Authors page)

Revised: 22 June 2017, last major update October 2013

Copyright: (c) 2003-2017, PathologyOutlines.com, Inc.

PubMed Search: Interdigitating dendritic cell tumor [title]

Cite this page: Interdigitating dendritic cell tumor. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/testisinterdig.html. Accessed October 23rd, 2017.
Definition / general
  • Rare tumor of hematopoietic origin arising from interdigitating dendritic cells (IDCs), a type of immune accessory cell found in lymphoid and nonlymphoid organs
  • IDCs present antigens to T cells and regulate cellular immune responses (Crit Rev Oncol Hematol 2013;88:253)
  • Usually arises in lymph nodes (Am J Surg Pathol 1999;23:1141)
Epidemiology
  • IDC tumors have been reported in all age groups (median age 56 years)
Sites
  • Can be nodal or extranodal; have been described throughout the body
  • Only two reported cases of testicular involvement
Pathophysiology
  • Dysregulation of immune system may facilitate malignant transformation of IDCs (Crit Rev Oncol Hematol 2013;88:253)
  • Recent studies show a clonal relationship between IDC tumors and low grade B cell lymphomas in patients harboring both diseases synchronously or metachronously
  • A group of IDC tumors likely develops secondarily after the malignant transformation and trans differentiation of B cells, rather than transformation of IDCs themselves
  • IDC tumors have developed following the use of calcineurin inhibitors, tacrolimus and pimecrolimus; these drugs dampen the responses of T cells to which IDCs present antigens
Clinical features
  • Painless testicular mass
Laboratory
  • Serum tumor markers for testicular germ cell tumors (hCG and alpha fetoprotein) are normal
Radiology description
Prognostic factors
  • Worse outcomes seen in younger patients and patients with intraabdominal involvement
  • Stage at presentation is most important prognostic factor (Crit Rev Oncol Hematol 2013;88:253)
Case reports
Treatment
  • Surgery with adjuvant chemotherapy
Gross description
  • Light tan, solid, may replace entire testis
Microscopic (histologic) description
  • Whorls and fascicles of spindle cells mixed with small lymphocytes
Microscopic (histologic) images

Images hosted on PathOut server:

Various images from lymph node



Images hosted on other servers:

Interdigitating dendritic cell sarcoma

Axillary lymph node transformation from CLL / SLL

Positive stains
Electron microscopy description
  • Complex interdigitating cytoplasmic dendritic processes, abundant rough endoplasmic reticulum, abundant mitochondria
Differential diagnosis