MUSCULOSKELETAL PRACTICALS

1. Musculoskeletal
block
Pathology
practical

2. Spinal TB - Pott’s Disease
(Tuberculous osteomyelitis)

4. Section of bone shows granuloma formation with
epithelioid like cells , langhans-type giant cells and rim of
lymphocytes

5. Osteochondroma
(osteochondroma exostosis)

6. This is an osteochondroma of bone. This benign lesion appears as a
bony projection (exostosis). Most are solitary, incidental lesions that
may be excised if they cause local pain. There is a rare condition of
multiple osteochondromatosis marked by bone deformity and by a
greater propensity for development of chondrosarcoma.

7. . A bluish-white cartilagenous cap
overlies the bony cortex

8. The microscopic appearance
of an osteochondroma displays
the benign cartilagenous cap
at the left upper and the bony
cortex at the right lower. This
bone growth, though benign,
can sometimes cause
problems of pain and irritation
that leads to removal
surgically.

10. Enchondroma of the fibula

11. CHONDROMA OF BONE

12. Chondroma:
Section of tumour shows
Lobules of mature cartilage separated by thin trabeculae of fibrous tissue
with blood vessels.
Lobules consists of mature cartilage cells irregularly distributed through
pale blue homogenous matrix and are contained within the lacunar
spaces singly, in pairs or in tetrads.
Few bony trabeculae are included in the tumour.

13. Giant cell tumour

14. Here is a giant cell
tumor of bone. The
proximal femur has
been amputated and
cut in half to reveal an
irregular dark red-
black hemorrhagic
mass in the epiphyseal
region. Giant cell
tumors are lytic on
radiography.

17. Histologically, giant cell
tumors of bone as seen
here are composed of
multinucleated giant cells in
a sea of round to oval
mononuclear cells. These
tumors are biologically
benign and are treated by
curettage or resection.
When radiated, they may
undergo malignant
transformation.

18. Practical on. 2

19.  An 18 years old female presented to the
rheumatology clinic with 2 months history of pain
and swelling in her upper thigh with weight loss .

26. Osteosarcoma

28. Chondrosarcoma

30. Here is another example of
a chondrosarcoma arising in
the pelvis. Note the
extensive nodules of white
to bluish-white
cartilagenous tumor tissue
eroding and extending
outward from the bone at
the lower right.
Chondrosarcomas can occur
over a wide age range, and
there is a slight male
predominance Many of
them are slow growing,
with symptoms present for
a decade or more.

31. This is the low power microscopic appearance of a
chondrosarcoma. The tissue is recognizable as cartilage,
and there are chondrocytes in clear spaces, but there is no
orderly pattern. At the bottom, this neoplasm can be seen
invading and destroying bone.

32. This high power microscopic appearance of a
chondrosarcoma demonstrates pleomorphic chondrocytes
that are piled together in a haphazard arrangement. In
general, chondrosarcomas occur over a wider age range
than osteosarcomas, including older adults.

33. METASTASES
MALE: PROSTATE
FEMALE: BREAST
RENAL, THYROID also
seek bone early also
LYTIC?
BLASTIC?

35. Here is a closer view of bone metastases. Virtually all bone
metastases are from carcinomas. The primary sites of
carcinomas that commonly go to bone are: breast,
prostate, kidney, thyroid, lung. Renal cell carcinomas tend
to be osteolytic (they destroy the bone) whereas prostatic
adenocarcinomas tend to be osteoblastic (they initiate new
bone formation).

36. At high magnification, metastatic infiltrating ductal
carcinoma of breast is seen within bone and filling the
marrow cavity. There is reactive new bone with pale pink
osteoid being laid down next to a bony spicule at the upper
left.

37. Practical no. 3

38. Lipoma

39. Lipoma of the neck
Benign, slow growing, subcutaneous skin growth. In this case, the
lipoma is rather large and located in the neck region. On palpation,
these are soft, nontender, and freely mobile.

40. Lipomas
Conventional
lipomas are soft,
yellow, well-
encapsulated
masses of mature
adipocytes; they
can vary
considerably in
size.

41. Lipomas
Histologically, they consist of mature
. white fat cells with no pleomorphism

42. Liposarcoma Morphology
Large relatively well-circumscribed lesions. soft tissue mass. The
mass is uncapsulated soft, yellow, lobulated,with marked areas of
hemorrhage and necrosis.

43. Liposarcoma morphology

44.  Microscopically :
 In most cases, cells indicative of fatty differentiation
are present. Such cells are known as lipoblasts; they
recapitulate fetal fat cells with cytoplasmic lipid
vacuoles that scallop the nucleus

45. Rhabdomyosarcoma

46. Rhabdomyosarcoma
Morphology
The gross appearance :
•It is variable. Tumor near the mucosal surfaces of
the bladder or vagina, can present as soft,
gelatinous, grapelike masses, designated
sarcoma botryoides. In other cases they are
poorly defined, infiltrating masses.
Histologically:
•Embryonal variants and sarcoma botryoides, are
composed of malignant small round cells and
eosinophilic large cells with evidence of
myoblastic differentiation.

47. Fibrosarcoma

50. FIBROSARCOMA (SOFT TISSUE)

51. Fibrosarcoma: Section of the tumour:
The tumor consists of interlacing fascicles of malignant
fibroblasts, arranged in a herringbone pattern.
Nuclear atypia and mitotic activity present.
The cells show marked variation in size and shape,
nuclear hyperchromatism with tumor giant cells
formation and many mitoses.