Parathyroid carcinoma of thymus

Mediastinum
Thymic carcinoma
Parathyroid carcinoma of thymus

Author: Hanni Gulwani, M.B.B.S.

Topic Completed: 1 December 2012

Revised: 14 February 2019

Copyright: 2003-2018, PathologyOutlines.com, Inc.

PubMed Search: Parathyroid carcinoma of thymus[TIAB]

Page views in 2018: 75

Page views in 2019 to date: 95

Table of Contents

Cite this page: Gulwani H. Parathyroid carcinoma of thymus. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/mediastinumPTH.html. Accessed July 19th, 2019.

Definition / general

May arise within thymus or adjacent soft tissue of anterosuperior mediastinum

Clinical features

Usually extreme hypercalcemia (> 14 mg/dl), markedly elevated parathyroid hormone (PTH) levels

Poor prognostic factors

> 5 MF/HPF, thick fibrous capsule or infiltrative growth pattern

Case reports

33 year old man with postoperative hungry bone syndrome (Endocr Pract 2003;9:152)
Hemodialysis patient with unusual thymic involvement (J Laryngol Otol 2004;118:162)

Gross description

Resembles primary thymic carcinoma
May invade adjacent lung, pericardium, thoracic great vessels
Unencapsulated

Microscopic (histologic) description

Modest to marked atypia
Sheets, nests or cords of polyhedral cells with round / oval hyperchromatic nuclei, occasional nucleoli, clear / granular cytoplasm
Focal mitotic activity, necrosis
May have internal collagenous bands

Microscopic (histologic) images

Images hosted on other servers:

Parathyroid carcinoma: site unknown

Positive stains

Diastase sensitive, PAS+, PTH (mosaic staining), variable chromogranin A or synaptophysin

Electron microscopy description

Primitive intercellular junctional complexes, prominent cytoplasmic glycogen, primitive blunt microvilli, sparse neurosecretory granules
No tonofilaments