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									                                                                                                                                       | Medicine
Soft Tissue Tumour

Fatty Tissue Tumour
             Lipoma                                                                      Liposarcoma
Nature       Benign                                                                      Malignant
Age          40-70                                                                       40-70
Site         Subcutaenous                                                                Proximal extremities
             Upper back                                                                  Retroperitoneum
             Shoulder/ Back                                                              Paratesticular
Clinical     Soft, Mobile, Painless (except angiolipoma)                                 Painless, Deep seated
Subtypes Fibrolipoma, Angiolipoma, Myelolipoma, Spindle cell lipoma, Pleomorphic         Well differentiated, Myxoid, Round cell, Pleomorphic, Dedi ferentiated
X-ray        Well-circums cribed, Homogen ous, Similar density as fat                    Lobulated with mass – contain strand of soft tissue slightly dense
HPE          Lobules of mature adipocytes                                                Heterogenous population of adipocytes
             Fibrous septae                                                              Lipoblasts
Rx           Complete resection                                                          Complete resection
Prognosis Good (except intramuscular type)                                               Depend on location, type

           Lipoma                                  Spindle cell lipoma                   Liposarcoma                               Liposarcoma
           Neoplastic adipocytes –                 Proliferation of adipocytes           Large mass lesion                        Adipocytes
           indistinguishable from normal           Disorganized bands of collagen –      Yellowish, like adipose tissue           Pleomorphism of neoplastic cells
           adipocytes                              contain spindle cells                 Well-differentiated                      (lipoblasts)

           Pleomorphic lipoma                      Cellular angiolipoma                  Liposarcoma                              Liposarcoma
           Floret cells (large pleomorphic cells   Well-circums cribed tumor             Large bizarre lipoblasts                 Well-differentiated atypical lipoma
           with nuclei around cell periphery)      Compose d of vascular proliferation                                            Fibrous septa (cellular septa)
                                                   Scattered fat cells
                                                   Thrombi (in blood filled spaces)

                                                                                         Liposarcoma                              Myxoid, Liposarcoma
                                                                                         Well-differentiated atypical lipoma      Branching capillary network
                                                                                         Pleomorphic nu clei scattered among      Small cells of myxoid liposarcoma
                                                                                         fat cells                                Lipoblasts
                                                                                                                                  Lymphangioma-like cystic

                                                                                         Pleomorphic, Li posarcoma
                                                                                         Cells with multiple grapelike vacuoles
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Smooth Muscle Tumour
           Leiomyoma                                                                    Leiomyosarcoma
Age        30-50                                                                        > 20
Sites      Uterus                                                                       Cutaneous (extremities & trunk)
           Skin, nipples, scrotum, labia                                                Large blood vessels (IVC) & deep soft tissue
           Intestine, less in deep soft tissue                                          Uterus
Signs &    Painless soft tissue swelling                                                Soft tissue swelling
Symptoms Painful in pilar leiomyoma                                                     Mass effect : obstruction
           Intestinal obstruction & urinary symptoms
Size       1-2 cm (e xcept uterus)                                                      > 5 cm
HPE        Circumscribed                                                                Interweaving fascicles of pleomorphic spindle cells
           Bland smooth mu scle                                                         ↑ mitosis
           Whorl pattern                                                                Necrosis
           < 1 mitosis/ 10 HPF (high power field)                                       Sarcomatous like MFH (malignant fibrous histiocytoma)
           Degenerative changes
IM         Actin + Desmin +                                                             Actin + Desmin +
Prognosis  Good                                                                         Depend on size, location, grade
                                                                                        Retroperitoneum - incomplete excision

                                                  Leiomyoma                             Leiomyosarcoma
                                                  Cells do not vary greatly in size &   Alternating fascicle pattern
            Uterine fibroids/ uterine leiomyoma   shape                                 Blunt-edged nuclei
                                                  Resemble normal smooth muscle         Minor pleomorphism present

            Blunt-ended elongated nuclei
            (smooth muscle proliferation)
                                                  Bizarre leiomyoma
                                                  Enlarged pleomorphic nuclei
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Skeletal Muscle Tumour
Rhabdomyoma                                                  Rhabdomyosarcoma (RMS)
Cardiac rhabomyoma (hemartomatous )                          Common soft tissue sarcoma – children, adoles cent
     1. Rare                                                 Cytogenic abnormalities
     2. < 5y/o
     3. Frequently associated with tuberous sclerosis        Diagnostic cell = rhabdomyoblast
     4. HPE – large, polygonal cells with glycogen
Adult rhadomyoma                                             Sites
     1. > 40 y/o                                                   1. Head & Neck
     2. Exclusively in Head & Neck region – eg.                    2. Genitourinary tract
           Oropharynx                                              3. Extremities
Genital rhabdomyoma                                          Histological subtypes
     1. 20-40 y/o                                             Embryonal RMS                        Alveolar RMS                         Pleomorphic/ anaplastic RMS
     2. Polypoidal lesion (spindle cell) at vagina, vulva,
                                                              Botyoid (sarcoma botryoides)
                                                              Spindle cell
                                    (genital type)
                                                              Infant & children                    Adolescent                           Adult
                                    Fibrous tissue
                                                              1. Head & Neck, GUS,                 Extremities, paranasal sinuses,      Extremities
                                    Spindling groups of
                                                                    retroperitoneum                retroperitoneum
                                                              2. Bladder, vagina, rectum,
                                    Long cytoplasmic
                                                                    nasal cavity, nasopharynx
                                    extensions with
                                                              3. Paratesticular
                                    parallel sides
                                                              Spindle cells                        Alveolar-like spaces                 Large, pleomorphic
                                                              Cross-striations                     Fibrous septae                       Multinucleated
                                                              Rhabdomyoblast                       Cross-striation                      ↑ mitosis
                                                              Primitive cells                      Rhabdomyoblast
                                                              Cambium layers
                                                              Abundant collagen

                                                              Rhabdomyosarcoma (Embryonal
                                                              Round cells with small oval nuclei   Rhabdomyosarcoma (Alveolar
                                                              Scanty eosinophilic cytoplasm        type)
                                                              Eccentric placement of n ucleus in   Tumor cells – grip fibrous septa
                                                              cytoplasm                            around alveoli
                                                                                                   Large pleomorphic cells with
                                                                                                   abundant cytoplasm

                                                              Rhabdomyosarcoma (Botryoid
                                                              type) Orbital conjunctiva
                                                              Dense aggregation of cells below

                                                              Rhabdomyosarcoma (Botyroid
                                                              Cambium layer
                                                              Loose texture
                                                              Differenting strap cells
                                                             IM – Vimentin, Desmin, Myogenin
                                                             Treatment – Surgery, Chemotherapy with or without radiotherapy
                                                             Prognosis – Staging, Age, Histological subtypes (Botryoid > Embryonal > Pleomorphic > Alveolar)
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Fibrous Tissue Tumour
Fibroma                     Fibromatosis                                            Fibrosarcoma
Rare                         Superficial                  Deep (Desmoid tumor)      Rare
Fibroma-thecoma in ovary     Palmar                       Extra-abdominal           Diagnosis by exclusion
Renal fibroma – hamartoma    Plantar                      shoulder, chest wall,     Sites
                             Penile                       back, thigh               Retroperitoneum, thigh, knee, distal extremities
                                                          Abdominal                 Gross
                                                          anterior abdominal wall   Uncapsulated, soft, infiltrative with areas of
                                                          Intra-abdominal           hemorrhage & necrosis
                                                          mesentery, pelvic wall    HPE
                             Male ↑                       Female ↑                  Fascicles of spindle cells
                             Benign                       Agressive locally         Herringbone pattern
                             Do not progress              Frequenty recur but       Frequent mitosis & necrosis
                                                          never metastasize         Prognosis
                             Fibroblasts                  Fibroblasts & collagen    Aggressive
                             Collagen deposit             Mitosis infrequent        50% recur
                                                                                    25% metastasize

                                                                                    Fascicles of spindle cells
                            Fibroblasts proliferate on collagen                     Lesion is cellular
                            Cytoplasm is inapparent, but visible if cut en face

                                                                                    Herringbone pattern
                                                                                    Differential diagnosis – synovial sarcoma, malignant
                                                                                    peripheral nerve sheath tumor
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Fibrohistiocytic tumour
               BFH (Benign fibrohistiocytic tumour)             DFP (Dermatofibrosarcoma protuberans)                    MFH (Malignant fibrohistiocytic tumour)
               Benign                                           Borderline                                               Malignant
               Dermatofibroma                                                                                            Common pathway for ST sarcoma progression
Age            20-50                                            20-50                                                    > 50
Sex            Male ↑                                           Male = Female                                            Male ↑
Sites          Skin                                             Trunk                                                    Proximal extremities
               Lower limb                                       Groin                                                    Retroperitoneum
               Head & Neck                                      Lower Limb
                                                                Head & Neck
Signs &       Slow growing dermal / Soft tissue (ST) mass       Exophytic                                                Large mass
Symptoms                                                        Multinodular painless growth                             Sometimes with pain
Gross         Fairly circumscribed nod ule/ mass                Poorly circumscribed                                     5-20 cm pse udo-capsule hemorrhage & necrosis
                                                                with entrapped skin adnexae & fat
Sub-types     -                                                 Classical                                                Storiform/ Pleo
                                                                Bednar tumour                                            Myxoid
                                                                                                                         Giant cell
Histo         Spindle cells                                     Spindle cells                                            Depends on subtypes
              Infiltrative margin                               Infiltrative margin
              Foam cells, hemosiderin, giant cells, epidermal   Prominent storiform pattern
              hyperplasia                                       Mitosis <5/10 HPF
Rx            Simple excision                                   Wide surgical resection                                  Wide surgical resection
Prognosis     Good                                              Recurrence (50% )                                        Aggressive (except angiomatoid)
                                                                Metastasis (5-15%)                                       Metastasis (30-50%)
                                                                                                                         60% - 5 year survival rate (YSR)

                                                                                                                         Malignant fibrous histiocytoma (Medium power)
              Benign fibrous histiocytoma                       Dermatofibrosarcoma protuberans
                                                                                                                         Storiform/ pleomorphic
              Hyperplastic epidermis                            Cartwheel/ storiform pattern
                                                                                                                         Pleomorphic nu clei scattered among smaller cells
              Dermal spindle cell lesion – contain lakes of     (without pleomorphism)
              blood                                             Thin nuclei, lack of perceptible cell borders, overall   Vague storiform pattern
              No endothelial lining of lakes                    tight quality of pattern

                                                                                                                         Malignant fibrous histiocytoma (High power)
                                                                                                                         Bizarre nuclei in huge cells found
                                                                Small fibrous histiocytomas
                                                                                                                         Inflammatory infiltrate
                                                                Cartwheel/ storiform cells
                                                                                                                         Spindle cells – irregular nuclear shapes, lack well-
                                                                Lack plaquelike growth in dermis/ subcutaneous fat
                                                                                                                         defined cell borders

              Malignant fibrous histiocytoma (angiomatoid)      Malignant fibrous histiocytoma (inflammatory)
              Dark cuff of lymphoid cells complete with                                                                  Malignant fibrous histiocytoma (Giant cell)
                                                                Malignant nuclei are larger & vesicular (not bizarre)
              germinal center                                                                                            Osteoclast-like giant cells
                                                                Sea of neutrophils & other inflammatory cells
              Lighter tumour nodules proliferate                                                                         Malignant tumour giant cells with enlarged nuclei
                                                                                                                                | Medicine
Blood vessel tumour
              Hemangioma                                                     Hemangioendothelioma                  Angiosarcoma
Nature        Benign                                                         Borderline                            Malignant
Age           Infant & children                                              > 40                                  > 40
Sites         Skin of Head & Neck                                            ST of extremities                     Skin of Head & Neck
              Liver                                                          Large veins                           Breast, liver, spleen
                                                                             Skin of Head & Neck                   ST of extremities
HPE          Benign endothelial cells                                        Proliferating endothelial cells       Malignant pleomorphic cells
             In lobules                                                      Cytoplasmic vacuoles containing RBC   Anastomosing blood vessels
Prognosis    Good                                                            Variable                              Very poor
                                                                             Majority cured by excision            Margin clearance difficult
                                                                             Up to 40% recur                       60% recur
                                                                             Up to 30% metastasize                 50% metastasize
               Capillary            Cavernous            Lobular capillary
               Infancy, early       Infant               Any age
               childhood            Children
               Female ↑             Female ↑             F=M
               Skin &               Skin &               Gingiva, fingers,
               subcutaneous of      subcutaneous         lip & face
               Head & Neck          Deep ST
               Lobules of s mall    Large blood-         As capillary type
               size vessel          filled vessels       Inflammation &
               Central “feeder”     Thrombi &            ulcer
               vessel               calcification
                                                                             Grade 2 Hemangioendothelioma          Angiosarcoma
               Spontaneous          No spontaneous       No spontaneous
                                                                             Vessel-forming growth pattern
               regression           regression           regression                                                Collagen as scaffold for end othelial cells
                                                                             Blood-filled spaces                   Too many cells line anastomosing spaces

                                                                             Spindle cell hemangioendothelioma
             Lobular capillary hemangioma (pyogenic granuloma)               Vacuolated endothelial cells
             (Medium power)                                                  Lining blood-filled channels
             Lobules are sharply demarcated by fibrous septa –
             hypercellular & lack spindy stream of cells in Kaposi disease

             Lobular capillary hemangioma (pyogenic granuloma)
             (High power)
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Peripheral Nerve Tumour
Neurofibroma                                         Schwannoma (neurilemmoma)                              Malignant peripheral nerve shealth tumour (MPNST)
20-40 y/o. 5-30 y/o (Diffuse)                        20-50 y/o                                              20-50 y/o
Childhood (plexifor m)                                                                                      Male = Female (but Male ↑ in neurofibromatosis)
Solitary                                             Soliary                                                = Neurofibrosarcoma
Diffuse                                              Multiple (3%)                                          = Malignant schwannoma
Any sites (especially Head & Neck)                   Extremities & Head & Neck
                                                     Cellular schwannoma – mediastinum, retroperitoneal,
Slow growing painless skin lesions                   Slow growing tumour                                    Soft tissue mass with/ without pain
Plaque-like in diffuse type                          Pain with neurologic symptoms
Tortous, worm-like nerve                             Headache, nasal obstruction, epistaxis, otitis media   Long sweeping fascicles & herring bone patterns
Elephantiasis neuromatosa                            Hearing loss + tinnitus                                Hypocellular myxoid areas (CT fibrosarcoma)
NF Type 1 (chromosome 17 )                           NF Type 2 (chromosome 22 )                             Nuclear palisading
No capsule                                           Well-circums cribed                                    Geographical necrosis
Fusiform, plaque, plexiform                          Encapsulated                                           Metaplastic changes (eg. Bone)
                                                     Dumbbell-shape d lesion                                Others – rosettes, glands formation, perivascular
Spindle cell in haphazard arrangement                Antoni A area                                          condensation, neuroepithelial differentiation like
Hypocellular area                                    Antoni B area                                          Ewing sarcoma
Mast cells                                           Verocay bodies                                         Epitheloid variant (CT melanoma or carcinoma)
                                                     Hyalinized blood vessels                               Triton tumour (MPNST + RMS differentiation)
Cured by excision (s olitary)                        Cured by excision                                      Wide surgical resection
Recur & ↑ risk malignancy (NF)

Neurofibroma                                         Schwannoma                                             Malignant peripheral nerve sheath tumour
Plexiform neurofibroma                               Dimorphic pattern of cellular (Antoni A)               Mitotically active & cellular tumour
                                                     Loose myxoid (Antoni B)                                Nuclei bullet shaped
                                                     Nuclear palisading (parallel rows of nuclei)           (blunt at one end, pointed at other)

Uniformly hypocellular
                                                                                                            Spindle cell carcinoma
Slightly myxoid
                                                                                                            Nervelike whorls
Undulating fibrillar background

Primitive Neuroectodermal tumour (PNET) (= Ewing sarcoma)
10-15 y/o
Swelling with pain & fever
Small uniform round cells with scanty cytoplasm
Very little stroma
Rosette formation
Aggressive tumour
Treatment with resection & chemotherapy +/- radioRx
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Synovial Sarcoma
Carcinoma of soft tissue
20-40 y/o
Lower > upper extremities & proximal > distal
Head & Neck, abdomen, retroperitoneum
Only 10% intra-articular
Radiographic findings
Deceptively well-circumscribed
Stippled calcifications
Mimic myositis ossificans (d ue to extensive calcification & metaplastic bone formation )
Pathologic findings
•     Fibrous elements
            o     Spindle cells (monotonous, uniform) in short fasci cles
            o     Collagen (variable stromal)
            o     Alternating hypercellular & hypocellular regions
•     Epithelial elements
            o     Gland formation
            o     Mucin production
•     Intratumoral calcifications
•     Cystic degeneration
•     Metaplastic bone reaction
Monophasic fibrous > Biphasic > Monop hasic epithelial > Poorly differentiated
Vimentin, EMA, Cytokeratin, CD99
Surgical resection (plus adjuvant therapy)
Risk factors for disease progression
Age > 25
Size > 5
High nuclear grade (poorly differentiated)
Necrosis > 50%
Rhabdoid morp hology
↑ Tumour stage
Disease-free survival
88% in low-risk group (<25 y/o, <5cm, no poorly differentiated)
18% in high-risk group

Synovial sarcoma (Biphasic type)
Small, oval, overlapping nuclei in spindle component

Synovial sarcoma (Monophasic type)                                                          Synovial sarcoma (Monophasic type)
Pericytomatous pattern                                                                      Focal cell cluster (indicate epithelial differentiation)
Solid areas

                                                                                            Synovial sarcoma
Synovial sarcoma (Reticulin stain)
                                                                                            Cytokeratin – glands, scattered spindle cells
Epithelial nesting pattern

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