1. Soft Tissue Tumors Flashcards
Describe the general features of Soft Tissue (Mesenchymal) Tumors.
- Submucosal lesions
- Appear similar to Salivary Gland Tumors
- Benign tumor of schwann cell origin, no axons.
- Associated with a nerve trunk
- H/N - tongue most common
- Slow-growing, solitary, encapsulated, rubbery-firm, most often non-tender mass
- May be seen in the Mandible, often involving the Mandibular Canal (odontogenic)
- Pain and paresthesia may occur in bony lesions
Neurilemoma (Schwannoma)
What is the Histologic Pattern assocaited with Neurilemoma (Schwannoma)?
-
Antoni A
- Palisaded nuclei arranged around Verocay bodies
-
Antoni B
- Loose arrangement of haphazard schwann cells, reticulin fibers and cystlike foci
What is Neurofibromatosis Type II?
-
Bilateral schwannomas of CN VIII vestibulocochlear nerve
- Tumor of the Ears
- Leading to progressive deafness, dizziness and tinnitus
What is a Neurofibroma composed of?
- Perineural fibroblasts
- Schwann cells
- Axons
What are the clinical features of a Neurofibroma? (4)
- Soft, dome-shaped, non-tender, superficial nodule, affecting skin most commonly
- If oral –> tongue, buccal mucosa
- Demarcated, but unencapsulated
- 90% are solitary, but 10% are multiple and associated with Neurofibromatosis
What is the Histology of a Neurofibroma? (3)
- Collection of spindle-shaped cells with wavy nuclei (comma-shaped)
- Mast cells are often seen
- Lesional tissue tends to mingle with the adjacent normal tissue
- Most common type (1/3,000 live births)
- Mutation of Chromosome 17-NFL gene (neurofibromin)
- 50% autosomal dominant; 50% new mutations
- Highly variable gene expression
- Some cases mild and others severe
Neurofibromatosis Type 1
(von Recklinghausen Ds of the skin)
What are the Skin Lesions of Neurofibromatosis Type 1?
- Cafe-au-lait spots
- Multiple Neurofibromas
- Axillary Freckling (Crowe’s Signs)
What is a pathognomonic skin lesion of Neurofibromatosis Type 1?
-
Plexiform Neurofibroma
- “bag of worms”
- A tortuous mass of expanded nerve branches embedded in a backdrop of neurofibromatous tissue
What are Lisch Nodules?
- Associated lesion of Neurofibromatosis 1
- Pigmented (melanocytic) iris hamartomas
- aka brown macules (freckles) in the iris
What are other accompanying but non-diagnostic features of Neurofibromatosis 1? (5)
- Hypertension
- Mental Deficiency
- Seizures
- Macrocephaly
- Short Stature
What are the Oral Lesions associated with Neurofibromatosis 1? (3)
- Neurofibroma affecting the: tongue, gingiva, bone
- Enlarged fungiform papillae
-
Bone Lesions:
- Enlargement or branching of the mandibular foramen
- Increased dimension of coronoid notch
What is the Prognosis of of Neurofibromatosis Type 1?
-
Reduced life expectancy due to:
- Vascular ds
- Variety of malignancies
- ~5% of pts develop malignant transformation of a neurofibroma –> malignant peripheral nerve sheath tumor
- Benign neoplasm possibly derived from schwann cells
- Develops on any cutaneous or mucosal surface, but 40% occur on the tongue (dorsal)
- Also on buccal mucosa and FOM
- Slow-growing, demarcated, unencapsulated, non-tender, firm, submucosal nodule
Granular Cell Tumor
What is the Histology of Granular Cell Tumor?
- Collection of mesenchymal cells with a granular-appearing cytoplasm
- Poorly circumscribed
-
PEH (pseudoepitheliomatous hyperplasia) in up to 50%
- May be mistaken for SCCA microscopically
What is the Treatment and Prognosis for Granular Cell Tumors?
- Conservative Excision - usually curative
- Prognosis is Excellent
What is the Pathogenesis of MEN 2B?
- Autosomal Dominant; 50% spontaneous mutations
- Mutation of RET proto-oncogene (chromosome #10)
What are the Clinical Features of MEN 2B? (4)
-
Marfanoid Build
- Thin elongated limbs, with muscle wasting
- Narrow face
- Thick, protuberant lips
- Eversion of upper eyelid
- Neuromas on eye
- Oral Mucosal Neuroma
- Medullary Carcinoma of the Thyroid (90%)
- Adrenal Pheochromocytomas (50%)
What are the Clinical Features of Oral Mucosal Neuromas associated with MEN 2B?
- Often 1st sign of ds
- Lips, anterior tongue, buccal mucosa, gingiva, palate
- Bilateral neuromas of commissure - highly suggestive
- Soft, yellowish
What are the Clinical Features of Medullary Carcinoma of the Thyroid (90%) associated with MEN 2B?
- Aggressive C Cell Malignancy (inc. calcitonin)
- Develops during childhood or adolescence
- Without Tyroidectomy - death ~21 yo
What are the Clinical Features associated with Adrenal Pheochromocytomas (50%) associated with MEN 2B?
- Frequently bilateral
-
Catecholamin production
- Diffuse sweating, diarrhea, headaches, flushing, palpitations, sever hypertension
What is the Characteristic Histopathology of MEN 2B?
-
Mucosal Neuroma
- Hyperplasia of schwann cells and axons
- Surrounded by a thickened perineural sheath
What are the lab values associated with MEN 2B?
- Inc. Calcitonin
- Urinary Vanillylmandelic Acid (VMA) with pheochromocytomas
What is the Prognosis of MEN 2B?
- Early diagnosis
- Prophylactic thyroidectomy at early age
- Die by 21 w/o
- Monitor for pheochromocytomas
What are the Highly Distincitve Clinical Features of Melanotic Neuroectodermal Tumor of Infancy (MNTI)?
- Rare tumor most often (91%) seen in the 1st year of life
- Neural Crest Origin
- Most develop in the bone of the anterior maxilla
- Rapid Growth
- May be brown or black in color
What is the Characteristic Radiographic Appearance of MNTI? (3)
- RL anterior maxilla
-
“tooth floating in space”
- Deciduous maxillary incisor is pushed labially
- Occasional osteogenic rxn mimicking Osteosarcoma
- “Sun Ray” radiographic appearance
What is the Characteristic Histology of MNTI? (2)
- Proliferation of small, dark, neuroectodermal-appearing cells that are nested aggregates
- Surrounded by plump, epithelioid cells that produce melanin
What are the lab values associated with MNTI?
-
VMA elevated in the urine
- Neural crest-derived tissues make NE-like hormones that are metabolized to VMA
- Concentration normalizes with tumor excision
What is the Prognosis of MNTI?
- Conservative excision is usually curative
- 20% recurrence with possible malignant behavior (metastasis) in a very small %
- May create a significant bone defect and failure of premanent teeth to develop
- Follow-up is warranted to fix defect
What is the etiology/pathogenesis of MPNST (Neurogenic Sarcoma - Neurofibrosarcoma)?
May arise spontaneously OR in association with NFT
What are the Clinical Features of Malignant Peripheral Nerve Sheath Tumor (MPNST)?
- Enlarging mass, pain/paresthesia is common
- Mandible, lips, buccal mucosa
What is the Histology of MPNST? (3)
- Invasive cellular proliferation of spindle-shaped cells with wavy nuclei
- similar to Neurofibroma
- Similar appearance to several other tumors with H-E stain
- S-100 positivity
What is the radiographic appearance of Neurofibrosarcoma (MPNST)?
Ill-defined, pushing teeth out of the way
What is the Treatment for MPNST?
- Radical surgical excision +/- adjuvant Radtx and Chemotx
What is the Prognosis for MPNST?
- Sporadic Cases (not assoc with NF) –> 50% 5-yr survival
- Thoose developing in the setting of NF1 –> may have worse prognosis