Answer for BIR CoW 08 Nov 2020
CALVARIAL TUBERCULOUS OSTEOMYELITIS WITH SUBGALEAL AND EPIDURAL ABSCESS
Findings
X-ray shows relatively well defined lytic lesion in right parietal bone without sclerotic rim MRI: Focal erosion with lysis noted in the right parietal bone with associated well defined peripherally enhancing extradural FLAIR mixed intense lesion in the right parietal region and another similar peripherally enhancing pericranial subgaleal lesion . The lesions show restricted diffusion and the adjoining superior sagittal sinus flow void is displaced inward. The above findings are consistent with Osteomyelitis and associated subgaleal and epidural abscess. Biopsy of the lesion was done and Histopathology revealed Multiple epitheloid granulomas with Langhan’s type of giant cells and peripheral cuff of lymphoid cells. Central foci of caesous necrosis and many congested blood vessels are seen- CASEATING TUBERCULOUS LESION.
Discussion
Tuberculosis of the calvaria is a rare entity. It usually presents as a painless scalp swelling, often with a discharging sinus. It most commonly involves the frontal and parietal bones. Causative organism is Mycobacterium tuberculosis.Calvarial tuberculosis occurs by hematogenous seeding of bacilli to the diploe. Cranial sutures do not prevent the spread of granulation tissue. Tuberculosis may present as a subgaleal swelling (Pott’s puffy tumor) with a discharging sinus when the outer table is involved. Involvement of the inner table is associated with formation of underlying extradural granulation tissue. It may progress to subdural empyemas, meningitis, and parenchymal granulomas. A high index of suspicion is important to recognize tuberculous involvement of the skull. In calvarial tuberculosis, conventional radiographs of the skull show focal bone destruction as rarefication or punched out defect often with accompanying soft tissue opacity. CT demonstrates the destruction of the calvaria with scalp involvement. Lesions in brain parenchyma,meninges and the extradural tissues are also detected. In MRI,T2-weighted images show a high-signal-intensity soft tissue mass with in the defect in bone. This may project into the subgaleal and/or epidural spaces and show peripheral capsular enhancement on the contrast-enhanced image. MR imaging is sensitive in demonstrating changes in the meninges and the ventricular walls and in detecting parenchymal foci of involvement.
Differential diagnosis: Eosinophilic granuloma, Ewing’s sarcoma, metastatic disease, multiple myeloma, Pyogenic infection.
Treatment: Surgical debridement, Antituberculous treatment.
Ref: Imaging Features of Calvarial Tuberculosis: A Study of 42 Cases Abhijit A. Raut, Arpit M. Nagar, Datta Muzumdar, Ashish J. Chawla, Ranjeet S. Narlawar, Sudhir Fattepurkar and Veena L. Bhatgadde American Journal of Neuroradiology March 2004, 25 (3) 409-414
Findings
X-ray shows relatively well defined lytic lesion in right parietal bone without sclerotic rim MRI: Focal erosion with lysis noted in the right parietal bone with associated well defined peripherally enhancing extradural FLAIR mixed intense lesion in the right parietal region and another similar peripherally enhancing pericranial subgaleal lesion . The lesions show restricted diffusion and the adjoining superior sagittal sinus flow void is displaced inward. The above findings are consistent with Osteomyelitis and associated subgaleal and epidural abscess. Biopsy of the lesion was done and Histopathology revealed Multiple epitheloid granulomas with Langhan’s type of giant cells and peripheral cuff of lymphoid cells. Central foci of caesous necrosis and many congested blood vessels are seen- CASEATING TUBERCULOUS LESION.
Discussion
Tuberculosis of the calvaria is a rare entity. It usually presents as a painless scalp swelling, often with a discharging sinus. It most commonly involves the frontal and parietal bones. Causative organism is Mycobacterium tuberculosis.Calvarial tuberculosis occurs by hematogenous seeding of bacilli to the diploe. Cranial sutures do not prevent the spread of granulation tissue. Tuberculosis may present as a subgaleal swelling (Pott’s puffy tumor) with a discharging sinus when the outer table is involved. Involvement of the inner table is associated with formation of underlying extradural granulation tissue. It may progress to subdural empyemas, meningitis, and parenchymal granulomas. A high index of suspicion is important to recognize tuberculous involvement of the skull. In calvarial tuberculosis, conventional radiographs of the skull show focal bone destruction as rarefication or punched out defect often with accompanying soft tissue opacity. CT demonstrates the destruction of the calvaria with scalp involvement. Lesions in brain parenchyma,meninges and the extradural tissues are also detected. In MRI,T2-weighted images show a high-signal-intensity soft tissue mass with in the defect in bone. This may project into the subgaleal and/or epidural spaces and show peripheral capsular enhancement on the contrast-enhanced image. MR imaging is sensitive in demonstrating changes in the meninges and the ventricular walls and in detecting parenchymal foci of involvement.
Differential diagnosis: Eosinophilic granuloma, Ewing’s sarcoma, metastatic disease, multiple myeloma, Pyogenic infection.
Treatment: Surgical debridement, Antituberculous treatment.
Ref: Imaging Features of Calvarial Tuberculosis: A Study of 42 Cases Abhijit A. Raut, Arpit M. Nagar, Datta Muzumdar, Ashish J. Chawla, Ranjeet S. Narlawar, Sudhir Fattepurkar and Veena L. Bhatgadde American Journal of Neuroradiology March 2004, 25 (3) 409-414
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!