GANGLIONEUROMA (ATLAS)

GANGLIONEUROMA

• It is a fully mature benign neoplasm of the sympathetic nervous system that usually occurs in older age group than Neuroblastoma

• Discovered incidentally but may present with VIP syndrome

• Age group-7 years of age or older

• Site– Arises in posterior mediastinum followed by the retroperitoneum particularly the presacral  space

• Other rare sites are

  • Cervical and parapharyngeal area

  • Urinary bladder

  • Prostate

  • Bone

  • Pancreas

  • Skin

  • Orbit

  • Paratesticular areas

  • Appendix

  • GIT

  • Spine cervical area

  • Adrenals

Gross findings:

• Well circumscribed (some as encapsulated)

• Size -8-15cm

• Tumors are firm and resilient and an cross section are gray white to tan yellow

• Sometimes trabecular or whorled appearance is also present

• Adrenal Ganglioneuroma are sharply circumscribed and delimited by residual adrenal cortex and capsule. But rarely may extend beyond the confines of capsule

Microscopic:

• Ganglioneuromas contain a variable admixture of mature or mildly dysmorphic ganglion cells and an over abundance of  mature Schwann cells

• Schawann cell component may be present as small fascicles or intersecting bundles which  are separated by loose myxoid stroma

• Considerable variation occurs in distribution of ganglion cells. Paucity of ganglion cells may lead to confusion with neurofibroma

• Well differentiated ganglion cells have compact eosinophilic cytoplasm with distinct cell borders and a single eccentric nucleus with a prominent nucleolus

• Occasional dysmorphic ganglion cells with single or multiple pyknotic nuclei may be seen

In adrenal GN:

• Tumor is sharply demarcated from adjacent adrenal tissue or can insinuate between adjacent cells

• Cellular atypia , mitotic activity and necrosis may be absent

• Some ganglion cells contain brown granular pigment which is lipofuscin or neuromelanin

• Other features that can be present are

  • Adipose tissue

  • Chronic inflammation

  • Collagenized stroma

• Malignant transformation into malignant peripheral nerve sheath tumor or rhabdomyosarcoma nay occur

• Rare cases shows leydig cells in the tumor and patient presents with virilisation

Differential diagnosis  –  maturing Ganglioneuroma can simulate intermixed Ganglioneuroblastoma. In Ganglioneuroma,  stroma  constitutes  >50% of the tumor

Reference:

Ernest E. Lack. Neuroblastoma, Ganglioneuroblastoma and other related tumors. In: Tumors of Adrenal Glands and Extraadrenal paraganglioma. AFIP Atlas of Tumor Pathology Series 4; Chapter 19: 463-477