Headache, palpitations, sweating, and high anxietyCASE A 43-year-old white man presents for reevaluation of recurrent episodes of palpitations, diaphoresis, headache, and acute
anxiety. At the initial visit 2 years ago, the patient complained of episodic palpitations with vague chest pain, which would
last for several minutes and then subside. At that time his BP was 120/72 mm Hg. A follow-up stress test had negative results.
The patient continued to have paroxysmal spells lasting about 15 minutes of palpitations, diaphoresis, headache, nausea, and
apprehensiveness several times a month. Following the gradual resolution of these symptoms, he reported feeling weak and washed-out.
At one point he was hospitalized for rapid atrial fibrillation, which converted back to normal sinus rhythm after medical
treatment.
While asymptomatic, the patient was never found to have significant BP elevation. Over time, the frequency of the attacks
increased to several times per week. Finally, a BP reading of 200/120 mm Hg was obtained during an episode; BP returned to
normal when the acute symptoms resolved.
What's your diagnosis? (IMAGES: JOHN M. PRATER, MD)
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At the current visit, a 24-hour urine test is collected for catecholamine metabolites and reveals high levels of metanephrine,
normetanephrine, and vanillylmandelic acid. The plasma-free metanephrine level is also significantly elevated. An abdominal
CT scan reveals a large (5.4 cm 13 cm) complex right adrenal mass (see the scan).
- What is the likely diagnosis?
- What steps would you take to treat the problem?
COMMENT The patient was diagnosed with pheochromocytoma, a rare and potentially life-threatening disorder with only 1 new case
per 2 million persons occurring annually. It is characterized as a catecholamine-secreting chromaffin cell tumor of the adrenal
medulla. A high index of suspicion is necessary to diagnose this neoplasm, as the clinical findings frequently mimic other
medical conditions. Sustained or paroxysmal hypertension is the hallmark diagnostic finding. At times the BP can be dangerously
elevated, leading to complications such as hypertensive crises. Signs and symptoms of paroxysmal catecholamine excess, including
the classic triad of palpitations, diaphoresis, and headache, are frequently seen during an episode. Patients often experience
anxiety or panic with an attack and are left with weakness and fatigue after resolution. Typically, 1 or more symptomatic
episodes occur weekly, generally lasting less than an hour.
Once the diagnosis is suspected, confirmation involves laboratory and radiologic evaluation. Twenty-four hour urine testing
for fractionated metanephrines and catecholamines is often done as an initial screen. However, testing for plasma-free metanephrines
is considered the test of choice because of its high sensitivity. Once biochemical assays are found to be elevated, tumor
localization must then be established. Both CT and MRI have good sensitivity for detecting adrenal tumors.
When a diagnosis of pheochromocytoma is confirmed, surgical referral is advised. Medical adrenergic blockade must first be
established for 2 to 4 weeks prior to surgery. Pharmacologic treatment is initiated, first with alpha-blockade, then beta-blockade
if the patient remains symptomatic. Removal of the tumor is generally curative, since 90% are benign (see the photograph).
Both conventional and laparoscopic techniques have proven successful. Hypertension resolves postoperatively in about 75% of
patients.
This patient underwent preoperative medical alpha- and beta-adrenergic blockade and noted nearly complete resolution of his
symptoms. Laparoscopic adrenalectomy was performed. Postoperatively, the patient had no further spells, remained normotensive,
and recovered completely.
SUGGESTED READING Brouwers FM, Lenders JWM, Eisenhofer G, et al. Pheochromocytoma as an endocrine emergency. Rev Endocr Metab Disord. 2003;4:121-128.
Klingler HC, Klingler PJ, Martin JK Jr, et al. Pheochromocytoma. Urol. 2001;57:1025-1032.
Kudva YC, Sawka AM, Young WF Jr. Clinical review 164: The laboratory diagnosis of adrenal pheochromocytoma: the Mayo clinic
experience. J Clin Endocrinol Metab. 2003;88:4533-4539.
Lenders JWM, Pacak K, Walther MM, et al. Biochemical diagnosis of pheochromocytoma: which test is best? JAMA. 2002;287:1427-1434.
Pacak K, Linehan WM, Eisenhofer G, et al. Recent advances in genetics, diagnosis, localization, and treatment of pheochromocytoma.
Ann Intern Med. 2001;134:315-329.
Phillips RA. Pheochromocytoma: how to diagnose, how to treat. J Clin Hypertens. 2002;4:62-72.
What's your diagnosis? (IMAGE: EHAB R. SAAD, MD)
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Recurrent pain, right lower abdomenCASE A 65-year-old man presented to the emergency department (ED) with right lower quadrant abdominal pain of 3 weeks' duration.
An abdominal CT scan showed a complex, thick-walled mass of the periappendix that was abutting the medial aspect of the cecum.
On abdominal CT scan with IV contrast, the mass demonstrated central areas of lower attenuation and enhancing walls (see the
scan). CT-guided aspiration revealed dark, cloudy fluid that grew Escherichia coli. The patient was discharged to home on oral antibiotics and scheduled for an elective appendectomy in 6 weeks.
However, 3 weeks later he had similar pain. A repeat CT scan of the abdomen showed marked thickening of the cecal wall with
a 3 cm 5 cm comma-shaped collection of fluid that was inferior and medial to the cecal tip. A second CT-guided aspiration
revealed predominantly acellular mucous material with a few nondysplastic degenerating cells entrapping proteinaceous debris.
The patient was discharged home to follow up with his primary care physician. One week later he has similar pain and presents
to the ED again. A repeat CT is obtained, and he is admitted to the hospital.
- What is the likely diagnosis?
- What is the recommended treatment?
(IMAGE: EHAB R. SAAD, MD)
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COMMENT The patient had an exploratory laparotomy that showed mucinous implants to the pelvis and peritoneum. Tumor debulking
with appendectomy and right hemicolectomy was performed. Histopathology of the appendix showed mucin-secreting epithelium
with focal papilliferous projections into the lumen and heaping of the nuclei (see the slide). Mitosis was fairly predominant
(see A). The tumor invaded through the muscularis propria into the subserosa (see B). Mucinous cystadenocarcinoma, which accounts
for 0.004% of all GI neoplasms, was diagnosed. Mucinous cystadenocarcinoma of the appendix occurs in patients from the 2nd
to the 9th decades, with mean age around the mid-50s. Men are affected slightly more often than women. Although preoperative
diagnosis is difficult, it is important to consider this in the differential diagnosis of right lower quadrant abdominal pain,
especially in the presence of typical CT scan findings, to allow for elective preparation before surgery.
The tumor may present with appendicitis, a palpable mass, rectal bleeding, pain, fistula or pseudomyxoma peritonei. Grossly,
it is indistinguishable from its benign counterpart and consists of creamy white or yellow-tan hard tissue with cystic areas
caused by accumulation of varying amounts of mucus. Microscopically, the tumor usually consists of well-differentiated tall
columnar cystic epithelial cells with at least 50% mucinous component. Invasion of the appendiceal wall is the only reliable
criterion for diagnosing adenocarcinoma.
Classical x-ray findings are a sharply circumscribed globular soft tissue mass, medial cecum displacement, and calcium deposition
in the soft tissue mass. On abdominal CT scan, the tumor occurs as a mass of near water density that is compressing or adjacent
to a contrast-filled cecum. On ultrasound, the tumor has variable sonographic echogenicity with consistently excellent through-transmission.
For early-detected disease, right hemicolectomy may offer a cure. Careful abdominal exploration is recommended because of
the high incidence of a concomitant second malignancy in the GI tract. For metastatic disease, surgical debulking and evacuation
of the mucus collection is recommended. The tumor has a slow growth rate, with a 5-year survival rate of 70% after right hemicolectomy
and 50% in patients with pseudomyxoma peritonei. The patient survived 2 years after the surgery. He died of extensive complications
from deep vein thrombosis.
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