Definition/General
Introduction:
Cervical leiomyoma is a benign smooth muscle tumor arising from the smooth muscle of the cervical wall
It is less common than uterine corpus leiomyomas but shares similar morphological and biological characteristics.
Origin:
Arises from smooth muscle cells within the cervical wall, including vascular smooth muscle and stromal smooth muscle elements
May develop from pre-existing smooth muscle or through metaplastic transformation.
Classification:
WHO Classification categorizes as benign smooth muscle neoplasm
May be classified as intramural, subserosal, or submucosal based on location within cervical wall.
Epidemiology:
Accounts for 5-10% of all uterine leiomyomas
Peak incidence 30-50 years
More common in women of African descent
Associated with reproductive hormones.
Clinical Features
Presentation:
Palpable cervical mass or enlargement
Abnormal vaginal bleeding
Dyspareunia
Urinary symptoms due to mass effect
May cause cervical distortion.
Symptoms:
Abnormal uterine bleeding (menorrhagia, metrorrhagia)
Pelvic pressure or pain
Dyspareunia
Urinary frequency or retention
Constipation if large.
Risk Factors:
Reproductive age
African American ethnicity
Nulliparity
Obesity
Family history of fibroids
Early menarche
Diet high in red meat.
Screening:
Pelvic examination reveals cervical enlargement or mass
Transvaginal ultrasound shows hypoechoic lesion
MRI provides detailed characterization.
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Gross Description
Appearance:
Well-circumscribed, firm, white to tan colored mass within cervical wall
Cut surface shows characteristic whorled pattern of smooth muscle.
Characteristics:
Size variable (1-15 cm)
Firm, rubbery consistency
White to tan coloration
Whorled, fascicular cut surface
Well-demarcated borders.
Size Location:
Can arise from any part of cervical wall
May be intramural, subserosal, or submucosal
Can cause significant cervical enlargement.
Multifocality:
Usually solitary but may be multiple
Often associated with uterine corpus leiomyomas
Can have various sizes within same patient.
Microscopic Description
Histological Features:
Composed of interlacing fascicles of mature smooth muscle cells
Cells have elongated, cigar-shaped nuclei and abundant eosinophilic cytoplasm
Minimal mitotic activity.
Cellular Characteristics:
Spindle-shaped smooth muscle cells
Elongated nuclei with blunt ends ("cigar-shaped")
Abundant eosinophilic cytoplasm
Minimal nuclear pleomorphism.
Architectural Patterns:
Interlacing fascicles in whorled pattern
Variable amounts of fibrous tissue between fascicles
Well-defined borders
Sparse vasculature.
Grading Criteria:
Benign tumor (no grading system)
Diagnosed by morphology: low mitotic count (<5/10 HPF), absence of coagulative necrosis, minimal atypia.
Immunohistochemistry
Positive Markers:
Smooth muscle actin (SMA) diffusely positive
Desmin positive
Caldesmon positive
h-Caldesmon positive
Estrogen receptor (ER) positive.
Negative Markers:
CD117 (c-kit) negative
CD34 negative
S100 protein negative
Cytokeratin negative
EMA negative.
Diagnostic Utility:
SMA and desmin confirm smooth muscle differentiation
Caldesmon helps distinguish from other spindle cell tumors
Hormone receptors support diagnosis.
Molecular Subtypes:
No specific molecular subtypes
Hormone-responsive tumors with estrogen and progesterone receptor expression.
Molecular/Genetic
Genetic Mutations:
Similar to uterine leiomyomas: MED12 mutations (most common), HMGA2 rearrangements, FH mutations
Chromosomal abnormalities in some cases.
Molecular Markers:
Hormone receptors (ER, PR) positive
Ki-67 proliferation index low (<1%)
Normal p53 expression
Smooth muscle differentiation markers positive.
Prognostic Significance:
Excellent prognosis as benign tumor
Complete excision curative
Malignant transformation extremely rare (<0.1%)
May recur if incompletely excised.
Therapeutic Targets:
Surgical excision (myomectomy, hysterectomy)
Hormonal therapy (GnRH agonists)
Uterine artery embolization in selected cases.
Differential Diagnosis
Similar Entities:
Cervical leiomyosarcoma
Inflammatory myofibroblastic tumor
Solitary fibrous tumor
Gastrointestinal stromal tumor (GIST)
Schwannoma.
Distinguishing Features:
Leiomyoma: low mitoses, no necrosis, minimal atypia
Leiomyosarcoma: high mitoses, necrosis, significant atypia
GIST: CD117 positive.
Diagnostic Challenges:
Cellular leiomyoma may show increased cellularity
Atypical leiomyoma has nuclear atypia but low mitoses
Size and location considerations.
Rare Variants:
Cellular leiomyoma
Epithelioid leiomyoma
Myxoid leiomyoma
Atypical leiomyoma (symplastic leiomyoma)
Mitotically active leiomyoma.
Sample Pathology Report
Template Format
Sample Pathology Report
Complete Report: This is an example of how the final pathology report should be structured for this condition.
Specimen Information
[specimen type], measuring [size] cm in greatest dimension
Diagnosis
[diagnosis name]
Classification
Classification: [classification system] [grade/type]
Histological Features
Shows [architectural pattern] with [nuclear features] and [mitotic activity]
Size and Extent
Size: [X] cm, extent: [local/regional/metastatic]
Margins
Margins are [involved/uninvolved] with closest margin [X] mm
Lymphovascular Invasion
Lymphovascular invasion: [present/absent]
Lymph Node Status
Lymph nodes: [X] positive out of [X] examined
Special Studies
IHC: [marker]: [result]
Molecular: [test]: [result]
[other study]: [result]
Prognostic Factors
Prognostic factors: [list factors]
Final Diagnosis
Final diagnosis: [complete diagnosis]