Spleen
Vascular tumors
Sclerosing angiomatoid nodular transformation

Author: Vijay Shankar, M.D. (see Reviewers page)

Revised: 8 March 2018, last major update January 2014

Copyright: (c) 2003-2018, PathologyOutlines.com, Inc.

PubMed Search: Sclerosing angiomatoid nodular transformation of the spleen

Cite this page: Shankar, V. Sclerosing angiomatoid nodular transformation. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/spleensclerosingangiomatoid.html. Accessed June 17th, 2018.
Definition / general
  • Sclerosing angiomatoid nodular transformation (SANT): rare benign lesion of spleen with unknown etiology (Arch Pathol Lab Med 2013;137:1309)
  • Also called multinodular hemangioma
Epidemiology
  • 2/3 women, mean age 48 years, range 30 - 60 years
Pathophysiology
  • Probably reactive, not neoplastic
  • May be splenic hamartomas which have undergone an unusual form of sclerosis, with a peculiar reactionary transformation of red pulp due to an exaggerated stromal response
Clinical features
  • Presents as asymptomatic splenic mass, abdominal pain or splenomegaly
Radiology description
  • Abdominal ultrasound, CT scans and MRI shows hypodense, sometimes multinodular splenic mass
  • CT or MRI with contrast cannot distinguish SANT from the surrounding spleen parenchyma
Radiology images

Images hosted on other servers:

Well circumscribed, highly vascularized

Expansible low density mass

5 cm tumor in hilus

Hypointensity of tumor


Splenic lesion at medial aspect

Lesion in lower spleen

Hypoenhancing mass

Prognostic factors
  • More aggressive if early age of onset
Case reports
Treatment
  • Splenectomy is standard treatment
  • Indications for splenectomy included increase in mass size, marked splenomegaly or lingering suspicion of malignancy
Clinical images

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Solid tumor

Laparoscopic view

Gross description
  • Bosselated mass, solitary lesion, 3 - 17 cm, sharply demarcated from remaining spleen
  • Composed of coalescing red-brown nodules in dense fibrous stroma
Gross images

Images hosted on PathOut server:

Case of the Week #364:


Images hosted on other servers:

Well defined nonencapsulated lesion

Well demarcated,
unencapsulated,
dark brown mass

0.3 - 0.5 cm red-brown multinodular lesions

Splenic resection

Microscopic (histologic) description
  • Micronodular appearance of slit-like, round or irregular shaped vascular spaces lined by plump endothelial cells with interspersed ovoid or spindle cells
  • Smaller nodules surrounded by concentric collagen fibers
  • Also numerous red blood cells
  • Stroma contains myxoid to dense fibrous tissue with scattered myofibroblasts, inflammatory cells
  • No / minimal atypia, no / rare mitotic figures, no necrosis
Microscopic (histologic) images

Images hosted on PathOut server:

Case of the Week #364:

H&E images


CD8

CD31

CD34



Images hosted on other servers:

Angiomatoid nodules

Slit-like, round irregular shaped vascular spaces

Concentric rims of collagen fibrils


CD31 highlights the abundant vascular structures

CD34 highlights the capillaries

CD8 highlights occasional sinusoid-like spaces

CD68 highlights scattered single cells

Positive stains
Electron microscopy description
  • Small vascular spaces lined by endothelial cells with pinocytotic vesicles but no Weibel-Palade bodies