American board of radiology

1. Atypical neoplasms 2
Dr. Jayanth H Keshavamurthy MD.

2. Bronchus-associated lymphoid
tissue lymphoma
• Primary pulmonary lymphoma is distinguished from the
more common secondary pulmonary lymphoma by lack
of extrapulmonary involvement.
• BALT lymphoma is the most common type of primary
pulmonary lymphoma.
• In a case of chronic multifocal consolidation or multiple
pulmonary nodules, BALT lymphoma should be
included in the differential diagnosis.

3. • Bronchus-associated lymphoid tissue (BALT) lymphoma is a rare
subtype of primary non-Hodgkin lymphoma that may occur within the
lung.
• BALT lymphoma has variable imaging findings and can mimic other
malignancies such as lung adenocarcinoma on CT.
• The most common findings include parenchymal abnormalities such as
nodules, masses, consolidation, and ground-glass opacity.
• Intrathoracic (hilar or mediastinal) lymphadenopathy is usually absent.

4. • Mucosa-associated lymphoid tissue (MALT) lymphoma is a subtype of
non-Hodgkin B-cell lymphoma that can occur anywhere in the body,
although it most frequently affects the gastrointestinal system.
• When it presents in the lung, it is called BALT lymphoma.
• BALT lymphoma accounts for at least two-thirds of primary pulmonary
non-Hodgkin lymphoma but is overall very uncommon.
• The pathogenesis involves long-term antigenic stimulation from
autoimmune, inflammatory, or infectious etiologies.
• Associations between BALT lymphoma and smoking, Sjögren disease,
multiple sclerosis, rheumatoid arthritis, diffuse panbronchiolitis, chronic
hypersensitivity pneumonitis, and Hashimoto thyroiditis have been
proposed.
• Most cases occur in patients over 50 years of age. Patients usually have
no symptoms at presentation, although chest discomfort, cough,
breathing difficulty, or hemoptysis may be present.

5. • On cross-sectional imaging with CT, BALT lymphoma typically
demonstrates nonspecific imaging findings, which include nodules,
masses, consolidation, and ground-glass opacity.
• Regions of consolidation may demonstrate indistinct borders and air
bronchograms. The lung may be involved in a focal or more diffuse
manner. Pleural effusions are uncommon. I
• ntrathoracic (hilar or mediastinal) lymphadenopathy is not a typical
feature of BALT. Differential considerations include such entities as
lung adenocarcinoma, organizing pneumonia,alveolar sarcoid,
multifocal pneumonia and pulmonary metastasis.
• Treatment usually consists of a combination of surgical resection,
chemotherapy, radiation therapy, and/or immunotherapy.
• Survival rates are relatively high because the disease is typically
diagnosed prior to extrapulmonary extension, and disease
progression is slow.

12. • Lymphangitic carcinomatosis, or lymphangitis
carcinomatosa, is the term given to tumour spread
through the lymphatics of the lung, and is most
commonly seen secondary to adenocarcinoma.

13. Pathology
• Lymphangitis carcinomatosa is most commonly seen
secondary to adenocarcinomas such as:
• breast cancer - most common
• lung cancer (bronchogenic adenocarcinoma)
• colon cancer
• stomach cancer
• prostate cancer
• cervical cancer
• thyroid cancer
• It can also be seen in numerous other primary cancers,
e.g. laryngeal cancer,pancreatic cancer, etc.

14. Radiographic features
• Radiographic appearances can most easily be divided
into those due to involvement of the peripheral
(interlobular septae) and central lymphatic system.
Involvement may be diffusely of both, or predominantly
of one or other compartment .
• Distribution of changes is variable, but most are
asymmetric and patchy .
• It is usually bilateral but may be unilateral especially in
cases of lung and breast cancer.

15. • CT, especially HRCT, is excellent at demonstrating both
peripheral and central changes.
• Typically the appearance is that of interlobular septal
thickening most often nodular and irregular, although
smooth thickening may also sometimes be seen . This
results in prominent definition of the secondary pulmonary
nodules, manifesting as tessellating polygons.
• Thickening of the bronchovascular interstitium is usually
irregular and nodular, with changes seen extending
towards the hilum .
• The combination may give a characteristic "dot in box"
appearance.

16. • subpleural nodules, and thickening on the interlobar
fissures
• pleural effusion(s): pleural carcinomatosis
• hilar and mediastinal nodal enlargement (40-50%)
• relatively little destruction of overall lung architecture

17. Differential diagnosis
• Considerations include a differential for that
of thickened interlobular septae, with common entities
comprising of :
• sarcoidosis
• viral pneumonia
• pulmonary oedema - changes are commonly bilateral
and often have a gravitational distribution
• radiation pneumonitis
• lymphocytic interstitial pneumonitis (LIP)

22. • KS should be considered in the differential in patients
with AIDS who have localized bone pain or a febrile
illness of unknown origin.
• Tissue sampling is required to confirm the diagnosis.
• Even though the majority of the lesions are lytic they
are usually not seen on plain films. CT or MRI is the
preferred imaging modality.

23. KS is caused by Human Herpesvirus 8. It is a low-grade mesenchymal neoplasm of blood and lymphatic origin primarily
affecting the skin. To date, four different types have been described: AIDS-related, African, classic, and transplantation/
immunosuppression. KS usually involves the lungs, gastrointestinal (GI) tract, liver, spleen, and skin. It rarely involves the
bone marrow, but there have been multiple biopsy-proven case reports. Bone marrow involvement has been associated
with a poor prognosis.

24. • On chest plain films, KS usually presents as middle to
lower lung zone reticular opacities and parenchymal
nodules. On CT, the pulmonary findings are bilateral,
symmetric, and poorly marginated nodules arising from
the hila. They are characteristically referred to as
“flame-shaped” nodules. These nodules tend to
coalesce and can grow to measure more than 1 cm
and show surrounding ground-glass opacities—this is
known as the “halo” sign. Diffuse lymphadenopathy
and bilateral pleural effusions are common findings.

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27. • Pancoast syndrome results from involvement of brachial
plexus and sympathetic chain by a Pancoast tumour, or
less commonly from other tumours involving the superior
pulmonary sulcus.
• The syndrome consists of:
• shoulder pain
• C8-T2 radicular pain
• Horner syndrome
• The classical syndrome is uncommon, with the Horner
syndrome present in only 25%.

32. • Hypertrophic osteoarthropathy is characterised by
periosteal reaction without an underlying bone lesion
involving the diaphysis and metadiaphysis of the long
bones of distal extremities.
• Clubbing of the fingers is seen most commonly in
patients with lung, liver, and gastrointestinal disorders.
• When associated with a pulmonary condition it is
termed hypertrophic pulmonary osteoarthropathy
(HPOA) and when associated with cancer is
considered a paraneoplastic syndrome.

33. Differential diagnosis
• General imaging differential considerations include:
• pachydermoperiostosis
• chronic venous insufficiency
• thyroid acropachy
• hypervitaminosis A

35. Ganglioneuromas
• Ganglioneuromas are benign tumors of the
sympathetic nervous system, most commonly found in
the posterior mediastinum
• They are typically homogeneously enhancing round or
oval masses which can contain punctate calcifications.

36. • Ganglioneuromas are tumors of the sympathetic nervous system that
originate from neural crest cells. Along with neuroblastomas and
ganglioneuroblastomas, ganglioneuromas are collectively known as
neurogenic tumors. These three are differentiated only by their stage of
neuroblast maturation. Ganglioneuromas are composed of mature
ganglion cells and are considered benign tumors.
Ganglioneuroblastomas and neuroblastomas are less mature and are
considered more aggressive and dangerous.
• The posterior mediastinum is the most frequent site of occurrence
(38% of cases), followed by the retroperitoneum. Tumors located in the
central nervous system are rare. Ganglioneuromas usually occur in
adolescents and young adults (60%) but patients of all ages can be
affected. The mean age of occurrence is 7 years. Patients are usually
asymptomatic and these lesions are typically discovered on routine
radiographs,

37. • On imaging, ganglioneuromas are well defined masses which
range in appearance from round to lobulated. They show
calcifications in 40% of cases and tend to grow around, rather than
displace, adjacent blood vessels.
• Tumors with intermediate to high signal intensity on T2 weighted
images have a higher degree of cellularity and more collagen,
whereas markedly high T2 signal signifies a high myxoid stroma
component and low cellularity.
• They also have characteristic curvilinear bands of low intensity on
T2 weighted sequences, giving a whorled pattern to the tumor as a
result of intertwined schwann cells and collagen fibers.
• Ganglioneuromas homogeneously enhance.

47. 1 r post treatment good response

48. • IMPRESSION: Extensive sites of extramedullary soft tissue
plasmacytoma
including bilateral lung pleura, bilateral mediastinum including
intensely in the inferior wall right atrium, head of the pancreas,
large tumor extending from the posterior wall of the descending colon,
lower para-aortic retroperitoneal, 2 mesenteric nodules, large
preaortic tumor beginning at the level of the bifurcation extending
inferiorly midline/left of midline into the lower pelvis supra-vesicle
region, bilateral pelvic sidewalls and periacetabular regions, deep
subcutaneous soft tissue nodule in the right buttock.

55. • Primary germ cell tumors of the anterior mediastinum are unusual.
• Seminomas, embryonal carcinomas, teratocarcinomas, and
choriocarcinomas account for the majority of reported cases .
Even less common is a histologically distinctive germ cell tumor
called an endodermal sinus tumor or a yolk sac tumor. A recent
publication summarized 1 2 reported cases of this tumor primary
in the mediastinum (all single case reports).
• Radiologists should include germ cell tumors in their differential
diagnosis of anterior mediastinal tumors.

58. Nodular pleural thickening
• Essentially all common causes of nodular pleural thickening are malignant and
include:
• metastatic pleural disease, particularly from adenocarcinomas, e.g:
– bronchogenic adenocarcinoma
– breast cancer
– ovarian cancer
– prostate cancer
– gastrointestinal adenocarcinoma
– renal cell carcinoma
• mesothelioma
• lymphoma
• invasive thymoma
• Thoracic splenosis is a rare benign cause of pleural nodularity.