# Cold Agglutinin Disease: A Rare Paraneoplastic Manifestation of a Thyroid Malignancy

## TL;DR

This paper reports a rare case of cold autoimmune hemolytic anemia linked to a thyroid cancer, highlighting its paraneoplastic nature.

## Contribution

The novelty is the rare association of cold-type autoimmune hemolytic anemia with thyroid malignancy as a paraneoplastic syndrome.

## Key findings

- Cold-type autoimmune hemolytic anemia is a rare paraneoplastic manifestation of thyroid cancer.
- Paraneoplastic syndromes are more commonly linked to warm autoimmune hemolytic anemia.
- Thyroid malignancy can present with non-mass-related symptoms like hemolytic anemia.

## Abstract

A paraneoplastic syndrome is the presence of signs and symptoms due to cancer, but it is not a consequence of the mass effect of a tumour. It typically occurs in middle-aged to older patients with solid tumors (lung, breast, and ovaries), and hematological malignancies (leukemia and lymphoma).

Autoimmune hemolytic anaemia is also a well-defined paraneoplastic phenomenon in lymphoproliferative disorders and rare solid tumour malignancies such as renal cell carcinoma, ovarian dermoid cysts, thymus cell cancer, Kaposi sarcoma, and cancers of the breast, pancreas, thyroid, and prostate. Most of the time, it is warm and is rarely cold type. We present a case of cold-type autoimmune hemolytic anaemia, presented as paraneoplastic manifestations of a thyroid malignancy.