Inflammatory myofibroblastoma can occur in many parts of the body. Its histological elements are myofibroblasts, histiocytes, plasma cells, and lymphocytes. Presence of these features suggests that this is a fibro-inflammatory lesion with abnormal extension of the reparative healing process after an unknown insult. Inflammatory myofibroblastoma is rarely found in the pleural space. It is also uncommon amongst tumours of the lung with an incidence varying from 0.04% [
1] to 0.7% [
2], but is rare in the pleural space. It has also been reported to arise from diaphragm [
3], heart, and many extra-thoracic locations such as liver, spleen, testes, epididymis, spermatic cord, bladder, salivary glands, spinal meninges and orbit.
The characteristics of this tumour include its bizarre presentation and unknown natural history, as in the case presented. This tumour may have variable physical consistency. Apart from semi-solid gelatinous consistency presented in this case it can also present as a solitary nodule [
4] and solitary or multiple calcified fibrous nodules [
5]. It can easily be confused with lung cancer when it appears as a solitary nodule on CT scan. Both benign and malignant pleural conditions can be confused with the non-solid presentation of this tumour. The case of inflammatory myofibroblastoma presented in this case report is unique due to its presentation as a long-standing haemothorax and it's non-solid physical appearance. This only adds to the diagnostic dilemma related with this tumour. Surgical treatment can be challenging in non-solid tumours, as complete removal can be difficult; resulting in a high risk of local recurrence. Distant recurrence has been reported as early as 3 months in the form of multiple bilateral pulmonary nodules and occurrence in multiple organs after lung resection has been reported [
6]. On the other hand two different series consisting of seven patients each have reported no evidence of recurrence with follow-up ranging from 0.5–13 yrs [
7,
8].
This case report emphasizes the difficulty in making preoperative diagnosis of pleural inflammatory myofibroblastoma. This lesion should be kept in mind when dealing with non-resolving haemorrhagic pleural effusions in absence of a suspicious malignant lesion. A low threshold to perform CT guided biopsy may offer preoperative diagnosis and better planning of surgical management in these tumours.