Tag Archives: Oncology

Mimicker: Inguinal Mesh Plug

Depending on the inguinal hernia repair method chosen, a mesh plug can be used for reinforcement. One such method uses a polypropylene (Prolene) plug

    • The post-operative appearance of an inguinal mesh plug can masquerade as an inguinal mass or lymphadenopathy

Imaging Findings

    • On CT, mesh plugs can have a slightly nodular or smooth outline. The density is similar to sightly lower than muscle. Mesh plugs have also been reported as a ring-like density with central fat attenuation, potentially mimicking epiploic appendicitis if on the left
    • On MRI, mesh plugs are typically T1 hypointense and demonstrate variable T2 weighted signal
    • Due to a granulomatous reaction, mesh plugs can be FDG avid

Helpful hints in preventing misdiagnosis

    • Mutliplanar reformations can be useful in demonstrating the conical morphology of the mesh plug, although they can appear ovoid
    • Postsurgical changes including skin thickening and suceptabliity artifact can also be helpful imaging features
Ryan Schwope mesh plug
Left inguinal mesh plug with a lobular contour
Ryan Schwope mesh plug cor
Left inguinal mesh plug. Note conical morphology on this coronal MPR.

References

The British Journal of Radiology, 77 (2004), 261–265
J Comput Assist Tomagr. 2008Jul-Aug;32(4):529-32.
American Journal of Roentgenology. 2010;195: 701-706.

Management of Pancreatic Cystic Lesions

Thick slab MRCP image showing massive dilatation of the main pancreatic duct

Incidental cystic pancreatic lesions found on 13% of MRI abdomens

    • Wide variety of pathology both benign and malignant

 

  • Imaging findings and demographics are the key to diagnosis
Ryan Schwope

 

Cystic Pancreatic Neoplasms (Four major categories)

 

    1. Serous cystadenoma: Benign (very low malignant potential)

 

    1. Mucinous cystic neoplasm (MCN): Premalignant or malignant

 

    1. Intraductal papillary mucinous neoplasm (IPMN): Malignant potential (Main Duct >> Branch Duct)

 

    1. Unusual cystic neoplasms:
        • Solid pseudopapillary neoplasm (SPN): Low grade malignancy
        • Cystic forms of more common neoplasms (neuroendocrine)

 

Nonneoplastic Pancreatic Cysts

 

    • Pseudocyst

 

    • Retention cyst

 

    • Lymphoepithelial cyst

 

    • Localized ductectasia

 

Major Imaging Features Guiding Management

 

    • Number and size of cystic components: Risk of malignancy increases when size ≥ 3 cm

 

    • Septations and solid components: Mural nodule has a 87% Sp and 56% Sn for malignancy

 

    • Main pancreatic duct (MPD) dilatation and communication with the cystic lesion: MPD > 10 mm has a 77% Sp and 67-92% Sn for malignancy

 

Sendai Criteria


High Risk Stigmata

    • Jaundice

 

    • MPD ≥ 10 mm

 

    • Enhancing solid component


Worrisome Features

    • Size ≥ 3 cm

 

    • MPD 5-9 mm

 

    • Non-enhancing mural nodules

 

    • Thick enhancing cystic wall

 

    • Lymphadenopathy

 

    • Abrupt Duct Termination

 

Management

 

    • Any worrisome features present = Endoscopic Ultrasound (EUS) and Cyst aspiration with fluid analysis

 

    • Any high risk stigmata present or suspicious cytology on EUS = Surgical resection

 

    • MCN or SPN = Surgical resection

 

    • Serous cystadenoma
        • 2-3 cm: F/U every 2 years
        • ≥ 4 cm: consider resection

 

    • IPMN:
        • Main duct and combined type: Surgical resection (but depends on location, pt. age/clinical status)
        • Branch duct type = follow if < 3 cm and contains no solid components
            • If < 2cm F/U q1yr; if growth FU q6mo
            • If 2-3 cm F/U q6mo x 2 years, then q1yr
            • Consider EUS (if mucinous then resect)
            • If growth ≥ 3 cm, resect

 

What the Clinician/Surgeon wants to know

 

    1. Number of cystic lesions

 

    1. Largest cystic lesion
        • Unilocular
        • Multilocular: Microcystic ( 2cm)

 

    1. Lesion size

 

    1. Lesion location: Head/Body/Tail

 

    1. Septations: None/Thin/Thick (> 2mm)

 

    1. Solid components: Present/Absent

 

    1. Calcifications: None/Coarse/Rim/Central

 

    1. Communication with MPD: Present/Absent

 

    1. Main pancreatic duct diameter: > 5 mm/Not dilated

 

References

 

    • Gandhi NS and Hecht E. “Adding Value to Clinical Care: Structured Reporting of Pancreatic Pathology”, Workshop Session Presentation, Society of Abdominal Radiology Annual Meeting, 2015

 

 

 

 

 

Bisphosphonate-related Osteonecrosis of the Jaw

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is associated with the use of bisphosphonates to treat severe osteoporosis, and metabolic and oncologic bone conditions, including hypercalcemia associated with malignancy. These agents inhibit osteoclasts, reducing bone resorption and osteolysis, and also possess antiangiogenic properties, reducing blood flow and necrosis. Patients with BRONJ present with pain and exposed, nonvital bone involving the maxillofacial structures. The incidence of BRONJ increases with the duration of treatment, especially with the intravenous route and concomitant steroid therapy. The osteonecrosis usually is participated by dental extraction. When spontaneous, it commonly occurs along the mylohyoid ridge. BRONJ can mimic osteomyelitis and osteoradionecrosis. A history of dental caries and the presence of periosteal elevation can help direct one towards the diagnosis of osteomyelitis. Osteoradionecrosis can be excluded if the patient has not received oropharyngeal radiation therapy. Jaw neoplasm, primary or metastatic, can potentially also mimic BRONJ. Treatment of BRONJ consists of cessation of bisphosphonate drug therapy, antibiotics for secondary infection, and surgical debridement of necrotic sequestra.

Ryan Schwope BROJN1
Figure 1: Axial CT of the facial bones. There is a mixed sclerotic and lytic lesion within the mandible (Figure 1, arrows) with foci of cortical interruption (Figure 2, arrowheads).
Ryan Schwope BROJN 2
Figure 2: Sagital CT of the facial bones. There is a mixed sclerotic and lytic lesion within the mandible (Figure 1, arrows) with foci of cortical interruption (Figure 2, arrowheads).

References:

Giant Cell Containing Lesions of Bone

Reactive

  • Brown tumor of hyperparathyroidism
  • Hemophiliac pseudotumor

Benign

  • Giant cell reparative granuloma
  • Non-ossifying fibroma
  • Giant cell tumor
  • Aneurysmal bone cyst
  • Chondroblastoma
  • Chondromyxoid fibroma
  • Langerhans cell histiocytosis
  • Pigmented villonodular synovitis

Malignant

  • Osteosarcoma
  • Clear cell chondrosarcoma
  • Metastatic carcinoma
  • Malignant fibrous histiocytoma
  • Solitary fibrous tumor metastasis