Waldenström macroglobulinemia: Imaging Checklist

Waldenström macroglobulinemia (WM) is a lymphoplasmacytic lymphoma that is associated with an immunoglobulin M (IgM) monoclonal protein (M-protein). To establish the diagnosis of WM, it is necessary to demonstrate IgM monoclonal protein in the serum, along with histologic evidence of lymphoplasmacytic cells in the bone marrow. There is a similar spectrum of disease to that seen multiple myeloma (MGUS, smoldering myeloma, and frank myltiple myeloma) in WM: IgM monoclonal gammopathy of undetermined significance, smoldering macroglobulinemia, and WM.

WM is more common in men and in whites. The most common presenting symptom is fatigue related to a normochromic or normocytic anemia. Patients can also have peripheral neuropathy. Hyperviscosity syndrome, which includes epistaxis, gingival bleeding, and retinal hemorrhage is related to high plasma IgM concentrations and is becoming less common due to earlier diagnosis. It is rarely seen in patients with IgM concentration of <4,000 mg/dL.

The checklist for reviewing images in these patients includes clinical features, complications of the disease, and potential mimickers. These include:

• Lymph nodes: The majority of patients have adenopathy on FDG-PET and CT.
• Bone marrow: Almost half of patients show diffuse increased uptake on PET, and about 90% will show marrow signal changes on MRI (diffuse in more than half). This can be due to marrow infiltration or hyperplasia due to anemia.
• Spleen size: Between 10-20% of patients will have splenomegaly on imaging
• Liver size: Hepatomegaly can be seen in patients, but the prevalence on imaging has not been reported.
• Viscera: Between 10-20% of patients will have visceral or extra-nodal sites of involvement on imaging.
• Venous patency: To assess for thrombosis due to hyperviscosity from high IgM protein
• Vessel walls: To assess for immune complex vasculitis due to IgM protein
• Presence of hemorrhage: Due to low levels of von Willebrand factor
• Central nervous system: To assess for presence of Bing-Neel syndrome, which is perivascular infiltration of small lymphocytes, lymphoplasmacytoid cells, and plasma cells in the brain parenchyma and/or spine.
• Amyloidosis: Imaging features of amyloidosis should be sought, since it can also present with an IgM monoclonal protein and neuropathy (particularly if the light-chain isotype is lambda).

WM can be difficult to differentiate from marginal zone lymphoma. MYD88 mutation L265P is more commonly seen in WM (67% of cases), and less commonly in splenic marginal zone lymphoma (4%) and mucosa-associated lymphatic tissue lymphoma (7%).

Because the M-protein of patients with WM is almost always IgM, a broad differential should be considered for lucent bone lesions (the M-protein of multiple myeloma is usually IgG, followed by IgA and IgD, with IgM myeloma making up about 1% of cases). The same can be said for sclerotic bone lesions with or without peripheral neuropathy (the M-protein of POEMS is usually IgG and IgA, with IgM POEMS being very rare). However, this information is not always available when interpreting initial staging studies for patients with newly diagnosed plasma cell dyscrasia.

References

• Banwait R, O'Regan K, Campigotto F, Harris B, Yarar D, Bagshaw M, Leleu X, Leduc R, Ramaiya N, Weller E, Ghobrial IM. The role of 18F-FDG PET/CT imaging in Waldenstrom macroglobulinemia. Am J Hematol. 2011 Jul;86(7):567-72.
• Gertz MA. Waldenström macroglobulinemia: 2013 update on diagnosis, risk stratification, and management. Am J Hematol. 2013 Aug;88(8):703-11.
• Moulopoulos LA, Dimopoulos MA, Varma DG, Manning JT, Johnston DA, Leeds NE, Libshitz HI. Waldenström macroglobulinemia: MR imaging of the spine and CT of the abdomen and pelvis. Radiology. 1993 Sep;188(3):669-73.

Radiographic Appearance of the Ascenda® 8780 and 8781 Intrathecal Catheters

The Ascenda® 8780 and 8781 intrathecal catheters are 3T MR conditional catheters and have a metallic marker in their catheter connectors that has the potential to be confused for a foreign body (it looked like a needle to me).

The metallic piece is inside the catheter connector. The connector is placed between the pump and spinal segments of the catheter and gives the user an audible and tactile confirmation of secure connection of the catheter segments.

A linear metallic object that is contiguous with the catheters on both views can help differentiate this from a retained foreign object.

The bottom image is from the Ascenda Manual

References

Ascenda Manuals and Technical Resources. Medtronic.

Sarcoid-Like Reaction in Oncology

Sarcoid is thought to develop in predisposed individuals by a cross-reaction to tumor, bacterial, viral, or inorganic antigens or immunogenes. Patients respond by forming noncaseating granulomas, which are most commonly intrathoracic. Sarcoid-like reaction (SLR) refers to the development of noncaseating granulomas in patients who do not fulfill the criteria for systemic sarcoidosis.

In oncological patients, SLR most commonly occurs in the lymph nodes draining a malignant tumor, but can also be observed in the organ of tumor origin and distant tissues. It develops after antineoplastic treatment with biologic modifiers (e.g., interferon and interleukin-2), single or combination chemotherapy agents, or even after surgery without chemotherapy.

The patient above has a history of melanoma of the left lower extremity with recurrent ipsi- and contra-lateral inguinal nodal involvement that has been treated with surgery (most recently 8 months ago) and chemotherapy in the remote past (cisplatin, vinblastine, and dacarbazine). The PET from 3 months ago (left panel) was clear. The new PET (right panel) shows new supraclavicular (red arrow), intra-thoracic (yellow arrows), and upper abdominal (blue arrow) adenopathy. The lymph nodes are highly FDG-avid and most prominent in the chest, where we see the symmetric hilar and mediastinal adenopathy typical of sarcoid and would be atypical for nodal involvement from lower extremity melanoma. It is important to keep SLR in mind in order to avoid over-calling disease progression. This can be more problematic in cases of intrathoracic neoplasms that would be expected to recur in the chest and involve hilar and mediastinal lymph nodes. Symmetrical hilar involvement can be a helpful hint in these cases.

References

• Inoue K, Goto R, Shimomura H, Fukuda H. FDG-PET/CT of sarcoidosis and sarcoid reactions following antineoplastic treatment. Springerplus. 2013 Dec;2(1):113.
• Tchernev G, Tana C, Schiavone C, Cardoso JC, Ananiev J, Wollina U. Sarcoidosis vs. Sarcoid-like reactions: The Two Sides of the same Coin? Wien Med Wochenschr. 2014 Jul;164(13-14):247-259.

Patterns of Lymphatic Drainage of the Paranasal Sinuses

Sinus	Lymphatic Drainage
Frontal	Submandibular (level IB)
Ethmoid	Submandibular (level IB)
Maxillary: Main	Lateral retropharyngeal and internal jugular (levels II, III, and IV)
Maxillary: Lateral antrum	Submandibular (level IB)
Sphenoid	Lateral retropharyngeal

References

• Som PM and Curtin HD. Chapter 2: Embryology, Anatomy, Physiology, and Imaging of the Sinonasal Cavities. in Head and Neck Imaging (5th ed.). Elsevier, 2011.
• Werner JA, Dünne AA, Myers JN. Functional anatomy of the lymphatic drainage system of the upper aerodigestive tract and its role in metastasis of squamous cell carcinoma. Head Neck. 2003 Apr;25(4):322-32.

Marjolin Ulcer

The strict definition of a Marjolin ulcer is a carcinoma that transforms from the chronic open wound of a pressure sore or burn scar. It is now used to describe any carcinoma arising from chronic wounds.

Average latency between ulcer formation and documentation of a malignancy is 30 years; however, intervals as short as 18 months have been reported. Between 1 - 2 % of chronic wounds develop malignant degeneration. The risk of developing malignancy in a venous ulcer is higher (about 20%).

These lesions behave aggressively and have a propensity for local recurrence and lymph node metastases.

The typical presentation is a 40- to 70-year-old man with osteomyelitis and a chronic lower extremity wound, who develops squamous cell carcinoma in the draining sinus tract ("warty tumors in cicatrices").

The image above is from a 50-year-old man with a chronic wound on his shin, with a small plaque that appeared about 1 year ago and has increased in size over the last 2-3 months. Biopsy showed squamous cell carcinoma.

Pyogenic granuloma can have a similar appearance on imaging, but is more common on the hands and feet, has a faster onset after injury/wound formation, and has a typical appearance on physical examination.

References

• Gilmore A, Kelsberg G, Safranek S. Clinical inquiries. What's the best treatment for pyogenic granuloma? J Fam Pract. 2010 Jan;59(1):40-2.
• Quitkin HM, Rosenwasser MP, Strauch RJ. The efficacy of silver nitrate cauterization for pyogenic granuloma of the hand. J Hand Surg Am. 2003 May;28(3):435-8.
• Zaballos P, Llambrich A, Cuéllar F, Puig S, Malvehy J. Dermoscopic findings in pyogenic granuloma. Br J Dermatol. 2006 Jun;154(6):1108-11.
• Trent JT, Kirsner RS. Wounds and malignancy. Adv Skin Wound Care. 2003 Jan-Feb;16(1):31-4.

"You keep using that word. I do not think it means what you think it means."

This post is futile. Language is an evolving process. Words have been joining, splitting, and changing meaning for as long as we've had language. The advent of printing helped slow down the process by disseminating "correct" definitions, but words will continue to evolve in spite of dictionaries and curmudgeons like me. That's a good thing.

The definitions of the words below will soon change to match their current "incorrect" usage, first as alternative meanings, and then as the accepted definition. This will happen as surely as ask is changing to aks/axe before our eyes, a continuation of the battle between āscian and āxian in Old English and asken and axen in Middle English.

Having said all that, the following is a list of incorrectly used words that you should feel free to ignore:

• Epicenter: This refers to a point on the Earth's surface directly above the focus of an earthquake or some other rumble down below. We have appropriated the term to replace plain old center. If we were to correctly use the term in radiology, we'd use epicenter to refer to the skin on top of a deep lesion: "The epicenter of the femoral lesion is on the skin of the medial thigh." See also penultimate.
  
  
• Serpiginous: Serpiginous (from serpere-to creep) is the term that is used to describe creeping and advancing skin diseases, such as ringworm or noduloulcerative cutaneous syphilis. This term is incorrectly used to describe snaky (serpentine) things like vessels or borders of bone infarctions. The person who is responsible for introducing serpiginous into the radiology literature in 1967 issued a correction in 1988, begging us to use serpentine instead. But the damage had been done. By then, the error had serpiginously crept its way into our mouths, and now spills out daily into millions of microphones and reports.
  
  
• Shotty: This refers to small lymph nodes that feel like buckshot under the skin. You must have serious palpation skills if you can feel shotty mediastinal or retroperitoneal lymph nodes! Bonus activity: Do a poll of your colleagues and trainees and see how many think (or thought) the word is actually shoddy. Bonus activity 2: Ask them what shotty/shoddy means in the context of lymph nodes.

References

• Di Chiro G, Doppman J, Ommaya AK. Selective arteriography of arteriovenous aneurysms of spinal cord. Radiology. 1967 Jun;88(6):1065-77.
• Di Chiro G. Serpentine (not serpiginous) vessels in spinal arteriovenous malformations. Radiology. 1988 Jan;166(1 Pt 1):286.

Vagus Nerve Neurofibroma

Vagus nerve neurofibromas are very rare. They can be located in cervical or mediastinal positions. They are slowly growing and typically asymptomatic.

While the vagus nerve itself can be hard to see, knowledge of the anatomy can be helpful in localization. The vagus nerve travels from the jugular foramen in the carotid sheath between the internal jugular vein (IJ) and internal carotid artery above C4 and between the IJ and common carotid artery (CC) to the root of neck.

The case above shows a T2-hyperintense structure between the IJ and CC at the base of the neck. In this patient with neurofibromatosis, the primary consideration is a vagus nerve neurofibroma.

References

• Gilmer-Hill HS, Kline DG. Neurogenic tumors of the cervical vagus nerve: report of four cases and review of the literature. Neurosurgery. 2000 Jun;46(6):1498-503.
• Kanzaki R, Inoue M, Minami M, Sawabata N, Shintani Y, Nakagiri T, Okumura M. Bilateral mediastinal neurofibroma of the vagus nerves in a patient with neurofibromatosis type 1. Ann Thorac Cardiovasc Surg. 2013;19(4):293-6.
• Matejcik V, Steno J, Haviarova Z, Mravec B. Neurofibroma of the vagus nerve in the cervical portion. Bratisl Lek Listy. 2008;109(10):455-8.
• Sesenna E, Magri AS, Corradi D, Ferri T, Ferri A. Malignant peripheral nerve sheath tumor of the vagus nerve in a teenager with the neurofibromatosis 1 gene mutation: a case report. J Pediatr Surg. 2011 Aug;46(8):e9-12.
• Shintani Y, Ohta M, Hazama K, Minami M, Okumura M, Hirabayashi H, Matsuda H. Bilateral cervicomediastinal neurofibroma originating from the vagal nerve in a patient with von Recklinghausen's disease: report of a case. Surg Today. 2002;32(12):1068-71.

Hypertrophic Osteoarthropathy

Hypertrophic osteoarthropathy (HO), formerly and incorrectly referred to as hypertrophic pulmonary osteoarthropathy, has primary and secondary forms. The primary form (pachydermoperiostosis) is often familial and is more commonly seen in males.

The secondary form can be seen in a variety of pulmonary and hepatic conditions, including:

• Lung cancer
• Mesothelioma
• Carcinomas of liver and gut
• Inflammatory bowel disease
• Liver cirrhosis
• Congenital cyanotic heart disease
• Pulmonary fibrosis
• Empyema
• Graves disease
• Thalassemia

Patients can present with clubbing of fingers, periostosis of distal long bones, thickening of skin over face and ankles, gynecomastia, and arthritis and synovitis. The synovitis is accompanied by a viscous, non-inflammatory effusion.

Various etiologies have been proposed, but the most recent thought is that it is due to arteriovenous shunting (e.g., in the liver, lung, or various tumors). The idea is that unfragmented megakaryocytes get delivered to distal sites in systemic circulation instead of being filtered in the lungs. This leads to production of growth factors (PDGF and VEGF), which lead to angiogenesis, endothelial hyperplasia. In certain lung tumors, there is de novo production of these growth factors by tumor, which makes it to the peripheral circulation.

A neurogenic role has also been proposed. This is supported by the fact that pain and deformity resolve with peripheral vagotomy in both primary and secondary forms, even with the primary tumor intact.

Differential diagnosis for Multifocal Periostitis in Adults and children were covered earlier.

References

Armstrong DJ, et al. Hypertrophic pulmonary osteoarthropathy (HPOA) (Pierre Marie-Bamberger syndrome): two cases presenting as acute inflammatory arthritis. Description and review of the literature. Rheumatol Int. 2007 Feb;27(4):399-402.