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LETTER TO EDITOR
Year : 2020  |  Volume : 68  |  Issue : 3  |  Page : 703--705

Central Nervous System Inflammatory Myofibroblastic Tumor Presenting as a Scalp Abscess

Binoy D Thavara1, Bijukrishnan Rajagopalawarrier1, Jyothi C Ramaswamy2, Geo Senil Kidangan1,  
1 Department of Neurosurgery, Government Medical College, Thrissur, Kerala, India
2 Department of Pathology, Government Medical College, Thrissur, Kerala, India

Correspondence Address:
Dr. Binoy D Thavara
Department of Neurosurgery, Government Medical College, Thrissur - 680 596, Kerala
India




How to cite this article:
Thavara BD, Rajagopalawarrier B, Ramaswamy JC, Kidangan GS. Central Nervous System Inflammatory Myofibroblastic Tumor Presenting as a Scalp Abscess.Neurol India 2020;68:703-705


How to cite this URL:
Thavara BD, Rajagopalawarrier B, Ramaswamy JC, Kidangan GS. Central Nervous System Inflammatory Myofibroblastic Tumor Presenting as a Scalp Abscess. Neurol India [serial online] 2020 [cited 2021 Jul 26 ];68:703-705
Available from: https://www.neurologyindia.com/text.asp?2020/68/3/703/289026


Full Text



Sir,

The Inflammatory Myofibroblastic tumor (IMT) is a heterogeneous group of rare lesions consisting predominantly of inflammatory cells and myofibroblastic spindle cells.[1] Central nervous system inflammatory myofibroblastic tumor (CNS IMT) is rare, with only approximately 100 cases reported in the literature. The etiology is unknown, but 60% have arisen from the dural or meningeal structures, and only 12% from intraparenchymal structures.[2] An aberrant or exaggerated response to tissue injury without an established cause has been favoured as the pathogenesis of IMT.[3]

A 47-year-old male patient presented with a pus discharging sinus from left parietal region. One year ago, he had noticed a gradually increasing scalp swelling. It was treated as a scalp abscess with incision and drainage. In the following months, he had noticed headache and intermittent minimal pus discharge from the incision site. In 2012, there was a history of head injury with right frontal sinus fracture. On examination, a 10 × 10 cm rounded prominence of the left parietal scalp with central scar and pus discharging sinus was noted [Figure 1]. Computed tomography (CT) scan and Magnetic resonance imaging (MRI) scan showed a 4.5 × 4 × 2.4 cm extra axial broad dural based left parietal lesion which has eroded the overlying bone and infiltrated into the scalp. T1 contrast image showed homogenous intense contrast enhancement of the tumor and its surrounding dura [Figure 2] and [Figure 3]a, [Figure 3]b, [Figure 3]c. There was no evidence of superior sagittal sinus thrombosis. Another 1.3 cm contrast enhancing nodular lesion was noted in the right parietal diploic space causing defect in the outer table. A provisional diagnosis of the intradiploic meningioma was made [Figure 3]a. Serum electrophoresis and Prostate Specific Antigen were normal. Chest X-ray and Ultrasound of the abdomen were normal.{Figure 1}{Figure 2}{Figure 3}

At surgery, the tumor was arising from the convexity and parasagittal dura. It has eroded through the parietal bone and infiltrated into the scalp [Figure 4]a and [Figure 4]b. It was a greyish-red moderately vascular tumor with firm to hard in consistency. Tumor capsule was noted. There was no macroscopic infiltration into the brain parenchyma. The tumor was excised along with 3 cm of surrounding dura. The dural defect was covered with polypropylene patch. Histopathological examination showed a neoplasm composed of spindle cells arranged in vague storiform pattern. Background showed dense inflammatory infiltrates of plasma cells, lymphocytes, eosinophils, and neutrophils [Figure 5]a. Immunohistochemistry (IHC) examination showed myofibroblastic spindle cells which were Smooth Muscle Actin (SMA) positive [Figure 5]b and Anaplastic Lymphoma Kinase (ALK) negative [Figure 5]c. Hence diagnosis of CNS IMT was made.{Figure 4}{Figure 5}

In WHO classification of CNS tumors (2016), IMT is classified as mesenchymal, non-meningothelial tumors. The behaviour of IMT is described as unspecified, borderline or uncertain behaviour.[4] It is a benign, non-metastasizing proliferation of myofibroblasts with a potential for recurrence and persistent local growth.[5] Radical resection and obtaining negative margins remain the mainstay of treatment.[6] The recurrence rate after gross total resection for ALK-positive and ALK-negative cases was 33% and 9%, respectively.[7] Hausler M et al., reported a case of left occipital IMT. After resection, patient developed a rapidly progressive local recurrence and a second intracerebral lesion.[2] In the author's case, patient has another small lesion in the right parietal intradiploic space, the pathology of which is not known. Localized or diffuse dural thickening of T2 low signal intensity and diffuse contrast enhancement combined with dural-based masses are a common MRI finding of meningeal intracranial IMT. Adjacent leptomeningeal involvement and dural venous sinus thrombosis are frequently associated.[8]

To conclude, the authors report the first case of locally aggressive CNS IMT, which has eroded through the skull bone and presented as a scalp abscess.[9] Trauma can be considered as one of the inciting agents for the development of CNS IMT. In every suspicious scalp swelling, intracranial extension should be ruled out before proceeding with surgery. Radiological diagnosis of CNS IMT is difficult in view of radiologically mimicking common tumors. The definitive diagnosis is done by using histology and IHC. The aggressiveness of the tumor is not well known in view of rarity of the tumor.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understand that name and initial will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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