Mechanism: tumor invasion of the lumbosacral plexus with sympathetic denervation of the lower extremity
Clinical features:
(1)
warm, dry foot
(2) pain (back, sacroiliac, upper leg, lower leg, lateral leg, ankle, foot), which may be intractable
(3) weakness of foot muscles
(4) variable loss of the ankle reflex
(5) variable sensory loss
(6) variable edema from lymphatic obstruction
A thermogram of the foot will show the affected foot to be hotter than the opposite side.
Possible causes:
(1) metastatic prostate cancer
(2) metastatic cervical cancer
(3) metastatic colorectal carcinoma
(4) metastatic renal carcinoma
(5) metastatic bladder cancer
(6) metastatic ovarian cancer
(7) primary retroperitoneal tumor
This may be the first sign of a primary or recurrent tumor and should alert the clinician to the possibility of an occult neoplasm.
