This document discusses several cases of bone and soft tissue pathology. Case 1 describes well-differentiated liposarcoma, which arises in older adults in deep soft tissues and has potential for local recurrence and de-differentiation. Case 2 involves angiolymphoid hyperplasia with eosinophilia, presenting as nodules or papules on the head. Case 3 is about enchondroma vs low-grade chondrosarcoma of the digits, which can be difficult to distinguish.

2. Common Diagnostic
Dilemmas in Bone and Soft
Tissue Pathology
Scott E. Kilpatrick, M.D.
Omar P. Sangueza, M.D.

3. Clinical and Radiologic Correlation
• Single most effective ancillary study!!
• Age? Anatomic Location?
• Bone vs. Soft Tissue Primary?
• Visceral Involvement?
• Neural and/or Vascular Involvement?
• Hetero- or Homogeneous? Cystic? Fatty?

4. Case 1: Well Differentiated
Liposarcoma (Atypical
Lipoma)
Scott E. Kilpatrick, M.D.

5. Well-differentiated Liposarcoma
The term “well-differentiated liposarcoma” is
synonymous with the designation “atypical
lipoma referring to a lesion that may locally
recur but, in the absence of de-
differentiation, will not metastasize.

6. Well-differentiated Liposarcoma
• Older adults
• Deep soft tissues, especially extremities
and retroperitoneum
• Cytogenetic abnormalities, most
commonly ring or giant marker
chromosomes
• Potential for local recurrence and de-
differentiation with mets

11. Residency Lessons from Wake
Forest University Medical Center
“If that’s Hodgkin’s Disease, then that’s a
Reed-Sternberg cell.”
R. D. Woodruff, M.D.
“If you wait until you see classic Reed-
Sternberg cells to make the diagnosis of
Hodgkin’s Disease, you’ll miss a lot of
cases of Hodgkin’s Disease.”
D. H. Buss, M.D.

12. Liposarcoma Lessons
• If that’s liposarcoma, then that’s a
lipoblast.
• If you wait until you see classic lipoblasts
to make the diagnosis of liposarcoma,
you’ll miss a lot of cases of liposarcoma.

19. Subtypes of well differentiated
liposarcoma
• Lipoma-like
• Sclerosing
• Inflammatory

26. Pleomorphic & Spindle Cell
Lipoma
• Elderly
• Head, neck, upper back & shoulders
• Chromosomal abnormalities, most
commonly aberrations of 16q
• CD34 positivity
• Note: similar pathology but different
clinical findings…call atypical lipoma
(low grade liposarcoma)

31. Hibernoma
• Young to middle aged adults
• Thigh, trunk, and upper extremity
• MRI signal intensity intermediate between
mature adipose tissue and skeletal muscle
• Varying proportions of white and brown fat

34. Clinical History:
The patient is a 31-year-old
female with a soft tissue mass
involving her left arm.

38. Case 2
Omar P. Sangueza, M.D.

39. Clinical History:
The patient is a 36-year-old male
with a skin/superficial soft tissue
mass involving his anterior
scalp.

50. Angiolymphoid hyperplasia
with eosinophilia.
• Nodules or papules of angiomatoid appearance
located mostly on the head, especially around
the ears, forehead and scalp.
• Less commonly lesions of AHE have been
described in the mouth trunk, extremities,
vulva,penis and inner canthus of the eye.
• Multiple lesions tend to be grouped or confluent.
• Lesions do not involute spontaneously and often
recur after excision

51. Synonyms
• Atypical pyogenic
granuloma
• Pseudopyogenic
granuloma
• Inflammatory
angiomatous nodule
• Inflammatory
arteriovenous
hemangioma
• Intravenous atypical
vascular proliferation
• Cutaneous
histiocytoid
hemangioma
• Epithelioid
hemangioma.
• Papular angioplasia

55. KIMURA’S DISEASE

61. Kimura’s Disease
• Skin-colored
subcutaneous masses
that in extreme cases
distort the outline of the
face dramatically.
• Intense peripheral
eosinophilia and
lymphadenopathy.
• No vascular abnormalities
• When plump endothelial
cells are present in the
blood vessels they are a
focal finding.
• Numerous, closely
packed lymphoid follicles
that extend throughout
the dermis and
subcutaneous fat, and
sometimes into the lymph
nodes and internal
organs.
• Numerous eosinophils.
• In brief, KD is not a
disorder of blood vessels,
but an inflammatory
systemic process of
unknown etiology.

67. Histopathological Features
• Well-circumscribed, dome-shaped lobules
surrounded by a collarette of epithelium
• Solid collections of endothelial cells
• Vascular spaces of different sizes and shapes,
lined by prominent endothelial cells with ample
cytoplasm, enlarged nuclei and prominent
nucleoli
• Neoplastic cells → vacuoles in their cytoplasm
• Inflammatory infiltrates
• Deposits of hemosiderin

68. Cutaneous Epithelioid Angiomatous Nodule: A Distinct
Lesion in the Morphologic Spectrum of Epithelioid Vascular
Tumors. Thomas Brenn, MD, PhD, and Christopher D.M Fletcher,
MD, FRCPath.
Am J Dermatopathol 2004. 26;1:14-21
• Epithelioid vascular lesions (15), Age: 15 to 79 yo
• Single (14/15) or multiple (1/15), small (0.5 cm)
erythematous to bluish nodules, short duration
• Distribution: trunk (8/15), extremities (5/15), face (1/15)
nasal mucosa (1/15)
• Circumscribed, solid proliferations of large epithelioid
endothelial cells with vesicular nuclei, intracytoplasmic
vacuoles
• Nuclear atypia was absent, deposits of hemosiderin
• No recurrence or metastasis in 30 months

69. Low-grade cutaneous
angiosarcomas
• Epithelioid hemangioendothelioma
• Endovascular papillary angioendothelioma
(Dabska's tumor)
• Retiform hemangioendothelioma
• Composite hemangioendothelioma

73. CD31

74. EPITHELIOID ANGIOSARCOMA

81. CD 34

82. CD 31

83. CYK

84. Epithelioid angiosarcoma
• EA is an uncommon histological variant of
angiosarcoma
• More frequent in young to middle age men
• Clinically, similar to other types of
angiosarcomas
• Location: lower extremity; breast, scalp and
face
• Causes: radiation exposure, foreign body
reaction and chronic immunosuppression

86. I am rich Potosi,
Treasure of the world.
The king of all
mountains,
And the envy of all
kings.

87. The Bolivian silver mines of the Cerro Rico mountain have
been exploited for over 450 years.

88. It is estimated than more than over
8 million people have died in the
mines

89. Case 3: Enchondroma of the
digit
Scott E. Kilpatrick, M.D.

90. Enchondroma vs. Low Grade
Chondrosarcoma of the Long
Bones
• Radiologic Features
• Pain
• Histologic Features

104. Enchondroma vs. Low Grade
Chondrosarcoma of the digits
• Soft tissue extension
• Extensive myxoid changes
• Permeation of bone

109. Enchondromatosis
• Ollier’s Disease
• Maffucci’s Syndrome (hemangiomas)
• Clinical manifestations at younger age
• Disease course variable
• Most sporadic (non-hereditary)
• Intramedullary, intracortical, subperiosteal

115. Clinical History:
The patient is a 35-year-old male
with a painful lytic lesion
involving the middle phalanx of
his right ring finger.

119. Case 4
Omar P. Sangueza, M.D.

120. Clinical History:
The patient is a 55-year-old male
with an infiltrating lesion above
the tip of the nose.

129. P75 S-100

132. W

141. DESMOPLASTIC
MELANOMA
• A helpful clue is the presence of lymphoid
aggregates within the dermis.
• Perineural an intraneural invasion is a common
event and the main cause for the propensity of
this tumor to persist.
• Compared to conventional melanomas of similar
thickness, DM has a better prognosis.
• May simulate scars or fibrous proliferations.

142. Desmoplastic melanoma:
• S-100+; HMB-45 -; p75+

143. LEIOMYOSARCOMA

148. ATYPICAL FIBROXANTHOMA

154. It is known as the mountain that eats men

156. Every seven years, for a period of four months,
all males between 18 and 50 were ordered to
work in the mines. They were paid a pittance
and rarely saw the light of day. Eighty per cent
of the male population of the 16 provinces of the
viceroyalty of Peru died in these conditions.
“Every peso coin minted in Potosi has cost the
life of 10 Indians who have died in the depths of
the mines,”
Fray Antonio de la Calancha in 1638.

157. Case 5: Leiomyoma of deep
soft tissues
Scott E. Kilpatrick, M.D.

158. Leiomyoma of Deep Soft Tissues
• Young to middle aged adults
• Extremities, pelvis and retroperitoneum
• Painless soft tissue swelling
• May be huge!! But typically well-
circumscribed
• By definition, mitotic activity is virtually
non-existent (<1/50 hpf)

162. Leiomyosarcoma of Deep Soft
Tissues
• Middle aged to older adults
• Retroperitoneum, large vessel intra-
abdominal, extremities
• Variable morphology depending upon
grade
• No specific cytogenetic abnormalities

169. Borderline Cases?
• Atypia and any level of mitotic activity
equals leiomyosarcoma
• Mitotic activity above 1/50 hpf

170. Ancillary Studies
• Smooth muscle actin and desmin
• In retroperitioneal tumors, ER and PR
helpful: Leiomyomas positive and
Leiomyosarcomas negative
• Most helpful in small biopsy specimens or
borderline histologic cases

171. Clinical History:
The patient is a 43-year-old
female with a large
retroperitoneal mass. She
underwent resection of the mass
and a hysterectomy. The
hysterectomy revealed
adenomyosis and a single 1.5 cm
subserosal leiomyoma.

176. Case 6
Omar P. Sangueza, M.D.

177. Clinical History:
The patient is a 9-month-old
male with a superficial soft
tissue mass involving his left
arm.

189. Fibrous Hamartoma of the
Infancy
• Rare, benign soft tissue tumor that typically
occurs within the first two years of life.
• The histogenesis is unclear.
• It is most commonly found in the axilla, shoulder,
inguinal region, and chest wall and is usually a
solitary malformation located in the
subcutaneous tissue or reticular dermis.
• Local recurrence is uncommon and treatment is
largely successful by local excision.
• The clinical course is typically benign and
prognosis excellent.

190. INFANTILE DIGITAL
FIBROMATOSIS
• Also known as Reye’s tumor.
• Almost all the lesions are noted within the
first 3 years of life.
• Up to one third of the cases are present at
birth.
• Lesions may be solitary or multiple.
• Usually limited to the fingers and toes;
thumb and great toe are usually spared.

195. PTAH

196. PTAH

197. INFANTILE DIGITAL
FIBROMATOSIS
• Tumors tend to recur after surgical
excision.
• Metastasis and underlying bony
involvement does not occur.
• Spontaneous regression has been
reported.

201. Cutaneous myofibroma
• Early lesions feature a prominent vascular
component with a variable numbers of
endothelium-lined vascular spaces that
branch irregularly to closely resemble
hemangiopericytoma.
• Mature lesions show either a nodular or a
multinodular pattern.

202. Cutaneous myofibroma
• The multinodular or biphasic type of adult
cutaneous myofibroma portrays multiple, well-
circumscribed nodules with spindle and plump
cells in whorls.
• Aged lesions of cutaneous adult myofibroma
have a leiomyomatous or fascicular appearance
with poorly circumscribed fascicles of spindle
cells which have pale eosinophilic cytoplasm
and elongated tapering nucleus

203. JUVENILE HYALINE
FIBROMATOSIS
• Rare hereditary disease
• Multiple cutaneous nodules, papules and
tumors.
• Gingival hypertrophy, joint contractures
and osteolytic defects.