Ovarian hemorrhagic cyst is a benign cystic lesion resulting from hemorrhage into a functional cyst (follicular or corpus luteum). Common in premenopausal women, typically presenting with acute pelvic pain. The most characteristic finding on ultrasound is the reticular/fishnet pattern (fibrin strands), with internal echo patterns evolving over time. No vascular flow is detected within the cyst on Doppler — this finding is critical in differentiating from solid neoplastic lesions. T1 hyperintense signal (methemoglobin) on MRI confirms the diagnosis. The vast majority show spontaneous resolution within 6-8 weeks.
Age Range
15-45
Peak Age
25
Gender
Female predominant
Prevalence
Common
Hemorrhagic cyst results from bleeding of vascular structures within granulosa cells of a follicular cyst or corpus luteum. During ovulation, the capillary network in the follicle wall ruptures, causing bleeding into the cyst. After hemorrhage, fibrin strands form and create a reticular network within the cyst — appearing as the pathognomonic fishnet/reticular pattern on ultrasound. Blood products undergo transformation over time: acute phase hyperechoic clot → subacute phase fibrin reticular pattern → late phase homogeneous low echogenicity or complete resolution. On MRI, methemoglobin (subacute blood) produces bright T1 signal because its paramagnetic effect shortens T1 relaxation time. No flow is detected within clot on Doppler — this is the fundamental criterion for differentiating from solid vascularized neoplastic components.
The thin, irregular web structure (lace/fishnet) formed by fibrin strands within the cyst is the pathognomonic ultrasound finding of hemorrhagic cyst. Fibrin strands extend from wall to wall and show no vascularity on Doppler — this is the fundamental criterion for differentiating from solid septation or neoplastic component. The pattern is most prominent in the subacute phase, potentially entirely hyperechoic in acute phase and completely anechoic in late phase.
Reticular web structure (fishnet/lace-like pattern) formed by thin, irregular fibrin strands within the cyst. Strands extend from wall to wall but contain no vascular structures.
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A reticular (fishnet) pattern formed by fibrin strands is observed within the ovarian cyst, consistent with a hemorrhagic cyst.
Hyperechoic clot adherent to cyst wall, with irregular margins, showing retraction. Clot shrinks over time and assumes jelly-like appearance. In acute phase, the cyst may be entirely hyperechoic.
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A hyperechoic clot component showing retraction and adherent to the cyst wall is observed, with no internal flow on Doppler.
No vascular flow detected in the echogenic area (clot/fibrin) within the cyst on color Doppler. Minimal vascularity may be present in cyst wall but no internal flow.
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No vascular flow is detected in the echogenic area within the cyst on color Doppler, consistent with clot and reducing the likelihood of solid neoplastic component.
Fluid-fluid level within the cyst: anechoic serum above, hyperechoic settled blood products below. Level changes with patient position (gravity-dependent).
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A gravity-dependent fluid-fluid level is observed within the cyst, consistent with hemorrhagic content.
Hyperintense (bright) signal on T1-weighted sequences — indicating presence of subacute blood product (methemoglobin). Signal intensity varies with age of blood products.
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The lesion shows hyperintense signal on T1-weighted sequences, consistent with subacute hemorrhagic content (methemoglobin).
T2 signal varies with blood product stage: early subacute (intracellular methemoglobin) hypointense, late subacute (extracellular methemoglobin) hyperintense. No T2 shading (endometrioma) present.
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The lesion shows heterogeneous signal on T2-weighted sequences without T2 shading; findings are consistent with a single hemorrhagic event.
Acute hemorrhage appears hyperdense (40-70 HU) within the cyst on CT. Density decreases over time. Density higher than water excludes simple cyst diagnosis.
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A ___ x ___ mm cystic lesion with hyperdense content (___ HU) is seen in the adnexal region, consistent with a hemorrhagic cyst.
Criteria
First 24-48 hours after hemorrhage. Homogeneous hyperechoic cyst on US (mimics solid lesion). Hyperdense (50-70 HU) on CT.
Distinct Features
Absence of internal flow on Doppler differentiates from solid lesion. Posterior acoustic enhancement may be preserved — suggesting cystic nature despite being hyperechoic. Follow-up US at 1-2 weeks reveals fibrin strand formation and reticular pattern emergence.
Criteria
1-4 weeks after hemorrhage. Fibrin strands formed, reticular/fishnet pattern prominent. T1 hyperintense on MRI.
Distinct Features
Most diagnostically clear phase — pathognomonic reticular pattern is most prominent during this period. Retracting clot and fluid-fluid level are common. T1 bright signal on MRI confirms diagnosis.
Criteria
After 4-8 weeks. Cyst shrinks, internal echoes decrease, may transform to simple cyst appearance or completely disappear.
Distinct Features
Size decrease and reduction/disappearance of internal echoes on follow-up US retrospectively confirms diagnosis. Cyst may completely resolve or leave small residual simple cyst. Size increase or solid component development is atypical and requires further evaluation.
Distinguishing Feature
Endometrioma shows T2 shading (T2 hypointense layer — recurrent hemorrhage accumulation), hemorrhagic cyst does not show T2 shading. Endometrioma shows homogeneous ground-glass echoes (US), hemorrhagic cyst shows reticular pattern. Endometrioma forms from cyclic bleeding and does not show spontaneous resolution.
Distinguishing Feature
Dermoid cyst shows hyperechoic component due to fat content but contains Rokitansky nodule (dermoid plug) and calcification (teeth/bone). Shows signal loss on fat-saturated MRI sequences. Hemorrhagic cyst lacks fat component and calcification.
Distinguishing Feature
Torsion may coexist with hemorrhagic cyst but ovarian enlargement (edema), peripheral follicular arrangement, whirlpool sign (pedicle swirl flow), and decreased/absent arterial flow are torsion findings. In isolated hemorrhagic cyst, ovary size remains normal and arterial flow is preserved.
Distinguishing Feature
Serous carcinoma shows solid enhancing papillary components and internal vascularity on Doppler. Ascites and peritoneal implants may accompany. In hemorrhagic cyst, solid-appearing component shows no vascularity (avascular clot) and demonstrates resolution on 6-8 week follow-up.
Urgency
routineManagement
conservativeBiopsy
Not NeededFollow-up
6-monthThe vast majority of hemorrhagic ovarian cysts are benign and show spontaneous resolution within 6-8 weeks. Follow-up US is recommended at 6-8 weeks after initial diagnosis — cyst shrinkage or disappearance confirms diagnosis. If size increase, solid component development, or vascularity appears on follow-up, MRI and/or surgical exploration is needed. Acute pelvic pain with hemodynamic instability (cyst rupture, hemoperitoneum) may require emergency surgical intervention. Hemorrhagic cyst is not expected in postmenopausal women — in this setting, neoplasia probability is higher and evaluation with MRI and tumor markers is needed.
Hemorrhagic cysts usually resolve spontaneously. May present with acute pelvic pain. Follow-up US at 6-8 weeks is recommended for lesions <5-7 cm. Persistent or growing lesions require further investigation.