# A Case of Factor XIII Deficiency Identified by Recurrent Postoperative Bleeding After Tonsillectomy

## TL;DR

A rare case of Factor XIII deficiency was identified in a patient who experienced repeated bleeding after tonsillectomy despite normal blood tests.

## Contribution

Highlights Factor XIII deficiency as a potential cause of postoperative bleeding when routine coagulation tests are normal.

## Key findings

- A 27-year-old man with normal coagulation tests had recurrent postoperative bleeding after tonsillectomy.
- Factor XIII activity was found to be reduced at 36%, confirming a deficiency.
- Bleeding stopped after administration of Factor XIII concentrate, stabilizing the patient's recovery.

## Abstract

Postoperative bleeding is a well‐known complication of tonsillectomy. Although inadequate hemostasis and vascular injury are common causes, occult coagulation disorders may also contribute. Factor XIII deficiency is an extremely rare condition that is particularly difficult to detect preoperatively because PT and APTT typically remain normal. A 27‐year‐old man underwent bilateral tonsillectomy for a recurrent peritonsillar abscess. Despite normal coagulation screening, the patient developed repeated postoperative hemorrhages requiring surgical management. Further evaluation revealed reduced Factor XIII activity (36%). After Factor XIII concentrate administration, bleeding ceased, and the postoperative course stabilized. Factor XIII deficiency should be considered in patients with recurrent postoperative bleeding despite normal routine coagulation tests. Early recognition and timely replacement therapy may prevent severe complications.

Postoperative bleeding is a known complication of tonsillectomy. The most common causes include inadequate hemostasis or vascular injury; rarely, coagulation disorders can also be implicated. Unlike hemophilia, which alters APTT, Factor XIII deficiency typically presents with normal PT and APTT levels, making preoperative detection more difficult.