and Soft Tissue Tumors

1. Patient age

0–5 years

Benign

Langerhans cell histiocytosis (LCH), osteomyelitis

Malignant

Fibrosarcoma, Ewing sarcoma, neuroblastoma, leukemia

5–10 years

Unicameral bone cyst (UBC), aneurysmal bone cyst (ABC), non-ossifying fibroma, fibrous dysplasia, osteoid osteoma, osteoblastoma, LCH, osteomyelitis

Osteosarcoma, Ewing sarcoma, rhabdomyosarcoma

10–20 years

Fibrous dysplasia, osteoid osteoma, osteoblastoma, non-ossifying fibroma, ABC, chondroblastoma, chondromyxoid fibroma, osteofibrous dysplasia

Osteosarcoma, Ewing sarcoma, adamantinoma, rhabdomyosarcoma

20 years

Giant cell tumor, enchondroma

Chondrosarcoma, lymphoma, leukemia, plasmacytoma, multiple myeloma, metastases (lung, renal, breast, thyroid, prostate)

2. Location

Epiphyseal

Benign

Chondroblastoma, subacute osteomyelitis, giant cell tumor (adult), osteochondroma, LCH

Malignant

Clear-cell chondrosarcoma (adult), Pagets (adult)

Metaphyseal

Giant cell tumor, unicameral bone cyst, aneurysmal bone cyst, non-ossifying fibroma, osteochondroma, fibrous dysplasia, subacute osteomyelitis, Langerhans cell histiocytosis, chondromyxoid fibroma

Osteosarcoma

Fibrosarcoma

Chondrosarcoma

Diaphyseal

Fibrous dysplasia, osteofibrous dysplasia, Langerhans cell histiocytosis, subacute osteomyelitis, enchondroma

Ewing sarcoma, leukemia, lymphoma, adamantinoma, chondrosarcoma

Multiple locations

Multiple hereditary exostoses, LCH, fibrous dysplasia, enchondroma, hemangioma

Leukemia, multiple myeloma, metastatic disease

Anterior spine

Eosinophilic granuloma, hemangioma, infection, giant cell tumor, chordoma, Paget’s

Leukemia, metastatic disease, multiple myeloma, osteosarcoma

Posterior spine

Osteoblastoma, aneurysmal bone cyst, osteoid osteoma

Metastatic (usually adults)

Pelvis

Aneurysmal bone cyst

Ewing sarcoma, osteosarcoma, chondrosarcoma, lymphoma

Langerhans cell histiocytosis

3. What is the lesion doing to the bone?

Lesional matrix

Ossification, mineralization (calcification), fibrous (“ground glass”)

Border of the lesion (wide or narrow zone of transition)

Circumscribed or geographic

Appears as though a line is drawn around the lesion

Slow growing

Narrow zone of transition

Moth eaten

Small holes in bone

Hard to define margin

Wide zone of transition

Rapid growth

Permeative

Wide zone of transition

Most aggressive, rapid growth

4. What is the bone doing to the lesion?

Cortical response

Slow-growing lesions are well contained, may expand cortex, but do not break through

Rapidly growing lesions are not contained and break through the cortex

5. Periosteal reaction

Buttress – trying to build up support for bone stress

Spiculated – “hair on end,” fast-growing/aggressive lesions

Solidification – thick periosteal new bone, slow process

Onion skin – several layers, fast-growing/aggressive lesions (Ewing sarcoma)

Interrupted – Codman triangle (triangular area of new bone formation from the periosteum)

../images/270913_2_En_42_Chapter/270913_2_En_42_Fig1_HTML.png — Fig. 42.1

(a–d) In austere settings tumors often present at an advanced stage, when palliative care is the only option

Funding for cancer treatment is limited, as even the basic health needs in LMICs (low- and middle-income countries) are not being met. While 84% of the world’s population resides in LMICs, only 5% of global resources to fight cancer go to them [2]. Palliative services are limited by both lack of trained health workers and access to essential drugs such as opioids.

General Principles

In the absence of advanced technologies for staging and treatment, the clinician must rely on clinical features, basic imaging studies, and limited pathology services (Table 42.1, Fig. 42.2). Features suggestive of malignancy include nonmechanical pain, rapid increase in size, fever, malaise, and weight loss. The prognosis depends on the specific tumor grade, size, and depth, patient age, medical comorbidities, nutritional status, and available resources.

../images/270913_2_En_42_Chapter/270913_2_En_42_Fig2_HTML.png — Fig. 42.2

Common bone tumors based on anatomic location

After a thorough history, physical exam, and plain radiographs, lesions suspected of being malignant should ideally be referred to a specialized center and staged prior to biopsy and definitive care, using the Musculoskeletal Tumor Society staging system. However, this relies on MRI to determine marrow extension, CT for local tumor extension and chest metastases, bone scintigraphy for skip lesions and mets, and reliable pathology, all of which are rarely available. In most resource poor environments, staging is limited to plain radiographs, a chest X-ray, and ultrasound to evaluate for abdominal, pelvic, or chest masses.

The biopsy of any lesion suspected of malignancy should be carried out at the treatment center where definitive services will be provided. One option is a core needle biopsy, which can be guided by X-ray, ultrasound, or CT. Open biopsies should be performed by the surgeon who will do the definitive surgery. Cultures should always be taken as chronic osteomyelitis can simulate malignancy and vice versa.

The basic principles of open biopsy should be followed: