What is the diagnosis and management for a 60-year-old female (F) with progressive unilateral swelling of the left leg, marked erythema, tense and shiny skin with dusky-red discoloration, significant edema, inflammatory changes, cachexia, and severe anemia?

Diagnosis and Management of Progressive Unilateral Leg Swelling with Cachexia and Severe Anemia

Immediate Diagnosis: Malignancy-Associated Deep Vein Thrombosis with Phlegmasia Cerulea Dolens

This clinical presentation—progressive unilateral leg swelling with erythema, tense shiny skin, dusky-red discoloration, cachexia, and severe anemia—strongly suggests extensive deep vein thrombosis (DVT) progressing to phlegmasia cerulea dolens (PCD) in the setting of underlying malignancy. 1, 2

Critical Diagnostic Pathway

Proceed immediately to complete duplex ultrasound from inguinal ligament to ankle without D-dimer testing, as the clinical presentation indicates high pretest probability for extensive DVT. 1 The combination of marked unilateral swelling with dusky-red discoloration represents a vascular emergency requiring urgent imaging that should not be delayed. 3, 1

• The dusky-red discoloration with tense, shiny skin indicates venous congestion severe enough to compromise arterial inflow, characteristic of PCD—a limb and life-threatening complication of massive DVT. 2
• PCD carries 20-40% risk of venous gangrene and compartment syndrome if not treated emergently. 2
• In 70% of pulmonary embolism cases, the thrombus originates from lower extremity DVT, making rapid diagnosis essential. 1

Underlying Malignancy Evaluation

The constellation of cachexia and severe anemia in a 60-year-old female with unprovoked DVT mandates immediate investigation for occult malignancy. 4

• Cachexia is the most common paraneoplastic syndrome and is associated with death in up to 20% of cancer patients. 4
• Cancer patients have significantly elevated DVT risk due to hypercoagulability, and D-dimer testing should not be used as a standalone test due to high false-positive rates. 1
• The severe anemia combined with cachexia suggests advanced disease with possible bone marrow involvement or chronic disease anemia. 3

Obtain the following studies emergently:

• Complete blood count with differential and peripheral smear to evaluate for hematologic malignancy. 3
• Comprehensive metabolic panel, lactate dehydrogenase, and uric acid to assess tumor lysis risk. 3
• CT chest/abdomen/pelvis with contrast to identify primary malignancy and assess for iliac vein compression by tumor. 1
• If ultrasound shows no proximal DVT but extensive unexplained swelling persists, image the iliac veins to exclude isolated iliac DVT from external compression. 1

Immediate Management Protocol

Initiate therapeutic anticoagulation immediately if ultrasound confirms DVT, without waiting for confirmatory venography. 1

• Use low molecular weight heparin as initial therapy, as it is preferred in cancer-associated thrombosis. 1
• Minimum anticoagulation duration is 3 months for proximal DVT, but cancer patients typically require indefinite anticoagulation. 5

Assess for compartment syndrome and need for fasciotomy:

• Perform four-compartment fasciotomy if there is evidence of arterial compromise, as prolonged ischemia leads to post-reperfusion compartment syndrome. 3
• Monitor for signs of venous gangrene including skin necrosis, bullae formation, or loss of arterial pulses. 2

Elevate the affected limb and apply compression therapy cautiously:

• Compression with minimum 20-30 mm Hg is recommended for chronic venous disease, but must be applied carefully in acute PCD to avoid worsening arterial compromise. 1
• Avoid complete bed rest once anticoagulation is initiated, as early mobilization reduces post-thrombotic syndrome risk. 3

Critical Pitfalls to Avoid

Do not dismiss this as simple cellulitis or chronic venous insufficiency—the unilateral presentation with cachexia and severe anemia indicates systemic disease requiring urgent evaluation. 1 Cellulitis typically presents with warmth and tenderness but not the dusky discoloration or severe edema seen here. 1

Do not delay imaging for D-dimer testing—this patient has high pretest probability and should proceed directly to ultrasound. 1 D-dimer has no role in high-probability patients and would only delay diagnosis. 1

Do not accept limited proximal-only ultrasound—complete evaluation including calf veins is necessary, as approximately 15% of untreated symptomatic distal DVT extends into proximal veins. 1

Do not overlook the need for oncology consultation—cachexia with severe anemia in the setting of unprovoked DVT requires immediate malignancy workup, as this may represent the first manifestation of advanced cancer. 4, 6

Prognosis and Follow-Up

The perioperative mortality of interventions in this setting can reach 5-10%, with postoperative complications occurring in approximately 50% of patients. 3 The patient's cachexia and severe anemia indicate poor performance status, which significantly impacts treatment options and prognosis. 3

If malignancy is confirmed, coordinate care with oncology for:

• Staging and treatment planning. 3
• Management of cancer-associated cachexia with early nutritional intervention. 4
• Treatment of severe anemia, which may require transfusion, erythropoiesis-stimulating agents, or treatment of underlying cause. 3
• Long-term anticoagulation strategy, as cancer patients require extended therapy. 5