C h a p t e r 2 5
Disorders of Renal Function
637
disease. Presenting features include hematuria, flank
pain, and presence of a palpable flank mass. Gross or
microscopic hematuria, which occurs in more than 50%
of cases, is an important clinical clue.
4
It is, however,
intermittent and may be microscopic; as a result, the
tumor may reach considerable size before it is detected.
One of the features of renal cell carcinoma is its abil-
ity to metastasize. In about 25% of new cases, there is
radiologic evidence of metastasis, with the most com-
mon sites being lung and bone metastases.
35
Ultrasonography and CT scanning are used to confirm
the diagnosis. MRI may be used when involvement of the
inferior vena cava is suspected. Surgery (radical nephrec-
tomy with lymph node dissection) is the treatment of
choice for all resectable tumors. Nephron-sparing sur-
gery may be done when both kidneys are involved or
when the contralateral kidney is threatened by an associ-
ated disease such as hypertension or diabetes mellitus.
Single-agent and combination chemotherapy have been
used with limited success. The 5-year survival rate is
90% if the tumor has not extended beyond the renal
capsule, but drops to 30% if metastasis has occurred.
5
R E V I EW E X E R C I S E S
1.
A 6-year-old boy is diagnosed with acute
glomerulonephritis that developed after a
streptococcal throat infection. At this time, the
following manifestations are noted: decrease in
urine output, increasing lethargy, hyperventilation,
and generalized edema. Trace amounts of protein
are detected in his urine. Blood analysis reveals
the following: pH = 7.35, HCO
3
= 18 mEq/L,
hematocrit = 29%, Na = 132 mEq/L,
K = 5.6 mEq/L, blood urea nitrogen
(BUN) = 62 mg/dL, creatinine = 4.1 mg/dL, and
albumin = 2 g/dL.
A.
What is the probable cause of this boy’s
glomerular disease?
B.
Use the laboratory values in the Appendix to
interpret his laboratory test results. Which
values are significant and why?
C.
Is he progressing to uremia? How can you tell?
2.
A 36-year-old man is admitted to the emergency
department with a sudden onset of severe,
intermittent, cramping pain that makes him feel
nauseated. He describes the pain as originating
in the left groin and radiating toward the flank.
Microscopic examination of his urine reveals the
presence of red blood cells. His temperature is
normal, and he does not exhibit signs of sepsis.
A.
What is the probable cause of this man’s pain?
B.
What diagnostic measure could be used to
confirm the cause of his pain?
C.
A plain-film radiograph reveals a 4- to 5-mm
kidney stone in the left ureter. What are the
chances that this man will pass the stone
spontaneously?
D.
What type of medications and other treatments
should this man receive?
E.
Once the stone has been passed, what type
of measures can he use to prevent stone
recurrence?
FIGURE 25-17.
Gross pathology of a bisected kidney showing
large renal cell carcinoma. Much of the kidney has been
replaced by gray and yellow tumor tissue. A little remaining
renal cortex and pericapsular fat are visible at the bottom of
this surgical specimen. (From the Centers for Disease Control
and Prevention Public Health Images Library. No. 863. Courtesy
of Edwin P. Ewing, Jr.)
SUMMARY CONCEPTS
■■
There are two major groups of renal neoplasms:
embryonic kidney tumors (i.e., Wilms tumor),
which occur during childhood, and renal cell
carcinoma, which occurs in adults.
■■
Wilms tumor is one of the most common
malignant tumors of children.The most common
presenting signs are a large abdominal mass and
hypertension.Treatment methods include surgery,
chemotherapy, and sometimes radiation therapy,
with long-term survival rates of up to 96% with
an aggressive plan of treatment.
■■
Cancer of the kidney accounts for about 3% of
all cancers, with renal cell carcinoma accounting
for 80% to 90% of cases.The neoplasms are a
collection of tumors from different parts of the
nephron, each with different genetic profiles and
histologic features that challenge both diagnostic
and treatment methods. Many of these cancers
are characterized by a lack of early warning signs,
diverse clinical manifestations, and resistance to
chemotherapy and radiation therapy.
