Osteolytic skull lesions: case of a large calvarial plasmacytoma. My-Linh Nguyen, MS IV Gillian Lieberman, MD September 17, 2010

Transcription

1 Osteolytic skull lesions: case of a large calvarial plasmacytoma My-Linh Nguyen, MS IV Gillian Lieberman, MD September 17, 2010

2 Agenda Our patient: brief clinical history Our patient: head CT Differential diagnosis of an osteolytic skull lesion Radiographic features of common osteolytic skull lesions Our patient: diagnosis and clinical course

3 Our patient: brief history 42-year-old woman complains of a rapidly enlarging painless bump on her scalp x 4mos. Physical exam reveals a firm, nontender 6cm subcutaneous nodule with normal overlying skin. She is referred to plastic surgery for excision of a presumed epidermoid inclusion or pilar cyst. The procedure is aborted intraoperatively due to suspicious appearance of the mass. A head CT is obtained.

4 1. Image also in: Nguyen M, Patel A. Plasmacytoma of the skull. N Engl J Med. 2010;363(22):e33. Our patient: osteolytic skull mass on head CT A 5cm wellcircumscribed osteolytic soft tissue mass is seen emerging from the right parietal calvarium Narrow zone of transition Our patient: axial c(-) CT head PACS, BIDMC 1 Hyperattenuating compared to brain parenchyma Rim of calcified bony fragments suggests an intraosseus, possibly intradiploic, origin

5 A quick explanation of intradiploic scalp Skull periosteum Outer table Cortical bone Diploic space: cancellous bone marrow blood vessels Intradiploic lesions often arise from these structures Image: Inner table Cortical bone periosteum

6 1. Adapted from: Reeder M. Reeder and Felson's Gamuts in Radiology. 4th ed. New York: Springer; Differential diagnosis of an osteolytic skull lesion 1 Common etiologies: 1. Inflammatory cholesteatoma 2. CNS epidermoid cyst 3. Fibrous dysplasia 4. Hemangioma 5. Osteomyelitis 6. Eosinophilic granuloma Let s go through this list using primarily the patient s CT to narrow the differential. 7. Metastastatic lesion (breast, lung, thyroid, kidney, neuroblastoma) 8. Plasmacytoma Let s run through the list

7 DDx #1: Companion patient 1 with inflammatory cholesteatoma Inflammatory cyst of the middle ear (location is key) Can cause local bone erosion Our patient s lesion Region of middle ear Cholesteatoma in characteristic middle ear location Location NOT consistent with inflammatory cholesteatoma! Companion patient #1: cholesteatoma 1 Axial CT head c(-) Our patient: lateral CT scout image. PACS, BIDMC 1. Hilal AA, Al Shaikhly AJ. Facial paralysis due to recurrent cholesteatoma seventeen years after first surgery. Qatar Med J 2003;12(1).

8 1. Adapted from: Reeder M. Reeder and Felson's Gamuts in Radiology. 4th ed. New York: Springer; Differential diagnosis of an osteolytic skull lesion 1 Common etiologies: 1. Inflammatory cholesteatoma 2. CNS epidermoid cyst 3. Fibrous dysplasia 4. Hemangioma 5. Osteomyelitis 6. Eosinophilic granuloma 7. Metastastatic lesion (breast, lung, thyroid, kidney, neuroblastoma) 8. Plasmacytoma Let s run through the list

9 Companion patient #2: intradiploic epidermoid cyst. 1 Axial CT head c(-) DDx #2: companion patients 2 and 3 with CNS epidermoid cyst Congenital cyst that grows via accumulation of cell debris including cholesterol and keratin Due to lipid content, is hypoattenuating compared to brain parenchyma 1. Image: Patel NP, Kramsky VN, Camins MB. Large intradiploic epidermoid tumor of the skull. African J of Neuro Sci 2006;25(1) Image: Osborn AG, Preece MT. Intracranial cysts: radiologic-pathologic correlation and imaging approach. Radiology. 2006;239(3): Low attenuation epidermoid cysts Our patient s lesion is hyperattenuating Companion patient #3: posterior fossa epidermoid cyst. 2 Axial CT head c(-) Our patient: axial c(-) CT head. PACS, BIDMC Attenuation pattern NOT consistent with epidermoid cyst!

11 1. Kransdorf MJ, Moser RP, Gilkey FW. Fibrous dysplasia. Radiographics. 1990;10(3): Branch CL, Challa VR, Kelly DL. Aneurysmal bone cyst with fibrous dysplasia of the parietal bone. Report of two cases. J. Neurosurg. 1986;64(2): DDx #3: Companion patients 4 and 5 with fibrous dysplasia Benign congenital disorder: osteoblast dysfunction causes replacement of normal bone with woven bone (mixed fibrous and osseous components) Lesions commonly have a ground glass appearance on CT (but less commonly can look homogenously cystic or sclerotic) Usually a disorder of children/young adults: 75% present before age 30 1 Typical ground glass appearance of fibrous dysplasia However, some lesions can look homogeneously cystic or sclerotic Our patient s lesion is hyperattenuating Companion patient #4: fibrous dysplasia. 1 Axial and coronal c(-) CT head. Companion patient #5: fibrous dysplasia. 2 Axial c(-) CT head. Based solely on our patient s CT, we cannot definitively rule out fibrous dysplasia. However, it would be an unlikely presentation given her age.

13 1. Heckl S, Aschoff A, Kunze S. Cavernomas of the skull: review of the literature Neurosurg Rev. 2002;25(1-2):56-62; discussion Huysse WCJ, Hogendoorn PCW, Bloem JL, De Schepper AM. Globular hemangioma of the calvaria. JBR-BTR. 2006;89(3): DDx #4: companion patients 6 and 7 with osseous hemangiomas Vascular lesion arising from diploic space CT: heterogeneous honeycomb pattern due to trabecular resorption in vascular channels and trabecular sparing between channels Calvarial hemangiomas demonstrating honeycomb trabecular pattern Aside from the bony fragments at its rim, no bone densities are seen within our patient s lesion Companion patient #6: hemangioma. 1 Companion patient #7: hemangioma. 2 Coronal c(-) CT head. Axial c(-) CT head. Our patient: axial c(-) CT head (bone window) PACS, BIDMC Attenuation pattern NOT consistent with hemangioma!

15 DDx #5: Companion patients 8 and 9 with osteomyelitis Bacterial or fungal infections. CT findings are non-specific: may see patchy bone destruction, associated soft tissue swelling, abscess Cutaneous abscess Subperiosteal abscess The bone destruction in our patient is not patchy, and there is no soft tissue swelling or abscess (the subcutaneous air seen is due to surgical exploration) Patchy bone destruction Patchy bone destruction Companion patient #8: frontal bone osteomyelitis secondary to frontal sinusitis. 1 Axial c(-) CT head. Companion patient #9: tuberculosis of frontal bone. 2 Axial c(+) CT head. 1. Anslow P. Cranial bacterial infection. Eur Radiol. 2004;14 Suppl 3:E Unüvar E, Oğuz F, Sadikoğlu B, et al. Calvarial tuberculosis. J Paediatr Child Health. 1999;35(2): Our patient: axial c(-) CT head (bone window) PACS, BIDMC Osteomyelitis is unlikely based on our patient s CT.

17 DDx #6: Companion patient 10 with eosinophilic granuloma Most common type of Langerhans cell histiocytosis Well-demarcated lytic mass, often containing a central button sequestrum of residual bone Intradiploic origin; may see beveled edge due to greater lysis of inner > outer table Eosinophilic granuloma with beveled edge and possible button sequestrum Our patient s lesion is also a well-demarcated mass of intradiploic origin. However, no beveled edge or button sequestrum is seen. Our patient: axial c(-) CT head (bone window) PACS, BIDMC Companion patient #10: eosinophilic granuloma. 1 Axial c(-) CT head. Based on our patient s CT, eosinophilic granuloma would be unlikely, though we cannot definitively rule it out. 1. Image:

19 1. Feng D, Rhatigan R, Shuja S, et al. Papillary thyroid carcinoma with metastasis to the frontal skull. Diagn. Cytopathol. 2009;37(7): Unüvar E, Oğuz F, Sadikoğlu B, et al. Calvarial tuberculosis. J Paediatr Child Health. 1999;35(2): DDx #7: Companion patients 11 and 12 with metastases Breast, lung, kidney, and thyroid cancers as well as neuroblastoma metastasize to calvarium Variable appearance; may see single or multiple masses with regular or irregular margins Hyperenhancing on c(+) CT due to increased vascularity Osteolytic thyroid cancer metastases demonstrating hyperenhancement on c(+) CT Companion patient #11: papillary thyroid carcinoma metastasis 1 Axial c(+) CT head. Companion patient #12: thyroid carcinoma metastasis 2 Axial c(+) CT head. Cannot rule out metastastis, which can take on variable appearances. Our evaluation is further limited because our patient did not receive IV contrast.

20 1. Adapted from: Reeder M. Reeder and Felson's Gamuts in Radiology. 4th ed. New York: Springer; Differential diagnosis of an osteolytic skull lesion 1 Common etiologies: 1. Inflammatory cholesteatoma 2. CNS epidermoid cyst 3. Fibrous dysplasia 4. Hemangioma 5. Osteomyelitis 6. Eosinophilic granuloma 7. Metastastatic lesion (breast, lung, thyroid, kidney, neuroblastoma) possible 8. Plasmacytoma Let s run through the list

21 DDx #8: Companion patient 13 with plasmacytoma of bone Tumor of plasma cells; may be solitary or a component of systemic multiple myeloma CT appearance: Well-marginated osteolytic mass arising from the diploic space (marrow) that is hyperdense on non-contrast CT and hyperenhancing on contrast CT. Lesion has no sclerotic margin but may have peripheral bone fragments. Plasmacytoma demonstrating classic appearance on c(+) CT. Peripheral bone fragments seen on bone window Companion patient #13: plasmacytoma of skull 1 Axial c(+) CT head Companion patient #13: plasmacytoma of skull 1 Axial c(-) CT head (bone window) Our patient: axial c(-) CT head. PACS, BIDMC Our patient s lesion, which is a well-circumscribed hyperdense mass arising from the diploic space (with peripheral bone fragments that are likely remnants of the destroyed Cannot outer rule bone out tables), metastasis could based be consistent our patient s with non-contrast a plasmacytoma. CT. 1. Okamoto K, Ito J, Furusawa T, et al. Solitary plasmacytomas of the occipital bone: a report of two cases. Eur Radiol. 1997;7(4):

22 1. Adapted from: Reeder M. Reeder and Felson's Gamuts in Radiology. 4th ed. New York: Springer; Differential diagnosis of an osteolytic skull lesion 1 Common etiologies: 1. Inflammatory cholesteatoma 2. CNS epidermoid cyst 3. Fibrous dysplasia 4. Hemangioma 5. Osteomyelitis 6. Eosinophilic granuloma 7. Metastastatic lesion (breast, lung, thyroid, kidney, neuroblastoma) possible 8. Plasmacytoma most likely diagnosis based solely on head CT!

23 Our patient s clinical course Mass was excised by neurosurgery; pathology revealed plasmacytoma Diagnosis of systemic multiple myeloma was subsequently made Additional osteolytic lesions found on skeletal survey (seen next slide) Bone marrow biopsy demonstrated a high percentage of plasma cells (20%) The patient is now doing well after chemotherapy and autologous bone marrow transplant. Let s run through the list

24 Our patient: skeletal survey revealing multiple lytic lesions Our patient: lateral plain film, head PACS, BIDMC Our patient: frontal plain film, right humerus PACS, BIDMC

25 In summary, we. Evaluated our patient s CT, which revealed a large osteolytic skull mass Generated a differential diagnosis for osteolytic skull lesions Learned the radiographic features of common osteolytic skull lesions Narrowed our differential and identified the most likely diagnosis based solely on imaging Learned that our imaging diagnosis matched our patient s pathologic diagnosis of plasmacytoma Reviewed our patient s clinical course, which included a diagnosis of systemic multiple myeloma

26 THANK YOU! Dr. Gillian Lieberman Emily Hanson Larry Barbaros Dr. Ferris Hall Dr. Jim Wu Dr. Kevin Donohoe Dr. Adam Jeffers Dr. Monica Agarwal Dr. Mai-Lan Ho Acknowledgements