CALR-Positive Essential Thrombocytosis Presenting With Microvascular Neuropathy: A Case Report

S. Nava Mallika Sreya ¹, N. N. Anand ^2*, Karthikeya T M ³, Bidisha Borthakur ⁴, AB. Adit Mithilesh ⁵, Ikkurthi Venkata Prem Narasimharao ⁶

¹Junior Resident, Department of General Medicine, Sree Balaji Medical College and Hospital, Chennai, Tamil Nadu, India.
Email: sarvepallisreya@gmail.com

^2*HOD, Department of General Medicine, Sree Balaji Medical College and Hospital, Chennai, Tamil Nadu, India.
Email: drnaganand1971@gmail.com

³Assistant Professor, Department of General Medicine, Sree Balaji Medical College and Hospital, Chennai, Tamil Nadu, India.
Email: tmkarthikeya@gmail.com

⁴Junior Resident, Department of General Medicine, Sree Balaji Medical College and Hospital, Chennai, Tamil Nadu, India.
Email: bidishapgm@gmail.com

⁵Junior Resident, Department of General Medicine, Sree Balaji Medical College and Hospital, Chennai, Tamil Nadu, India.
Email: mithilesh.adit@gmail.com

⁶DNB Pulmonary Medicine, DM Resident, Department of Pulmonary, Critical Care & Sleep Medicine, GMCH Chandigarh, India.
Email: premnarasimharao10@gmail.com

*Corresponding Author: Dr. N. N. Anand, HOD, Department of General Medicine, Sree Balaji Medical College and Hospital, Chennai, Tamil Nadu, India. Email: drnaganand1971@gmail.com

Received: 19th Dec, 2025; Revised: 6th Feb 2026; Accepted: 12th Feb, 2026; Available Online: 28th Feb, 2026

---

ABSTRACT

Essential thrombocytosis (ET) is a chronic myeloproliferative neoplasm characterized by sustained thrombocytosis and megakaryocytic proliferation in the bone marrow. Although vasomotor symptoms such as headaches and erythromelalgia are well recognized, peripheral neuropathy as an initial manifestation remains uncommon. We describe a 55-year-old woman who presented with progressive burning limb pain and distal sensory disturbances. Laboratory testing revealed marked thrombocytosis and moderate anemia, and molecular analysis confirmed a CALR mutation. Bone marrow examination demonstrated typical megakaryocytic hyperplasia with hyperlobulated forms and minimal reticulin fibrosis. Her symptoms were attributed to microvascular ischemic injury affecting the peripheral nerves. This case highlights the importance of recognizing atypical neurological manifestations in CALR-mutated ET and reinforces the diagnostic value of molecular testing in distinguishing ET subtypes.

Keywords: Essential thrombocytosis, CALR mutation, Peripheral neuropathy, Microvascular complication, Thrombocytosis.

How to cite this article: Sreya SNM, Anand NN, Karthikeya TM, Borthakur B, Mithilesh ABA, Narasimharao IVP. CALR-positive essential thrombocytosis presenting with microvascular neuropathy: a case report. Int J Drug Deliv Technol. 2026;16(5s): 410-411; DOI: 10.25258/ijddt.16.5s.56

Source of support: Nil.

Conflict of interest: None