Letters to the Editor

FPs, Internet Play Crucial Roles in Diagnosis of Complex Illnesses

TO THE EDITOR: An 18-year-old woman presented to my office with severe left buttock pain radiating down her posterior thigh, and mild left lower quadrant pain. She had no nausea, vomiting, diarrhea, chills, fever, or sweats. Her medical, family, and social history and review of systems were noncontributory. She was allergic to penicillin.

On examination, she was in moderate distress. Her temperature was 37.2°C (99.0°F). No icterus was present. Her abdomen was benign, and findings on pelvic examination were normal. Her left sciatic notch was tender, with a positive left straight-leg raise. My initial impression was acute sciatica, but the abdominal pain and high normal temperature made my diagnosis uncertain. I prescribed celecoxib and rest, and arranged close follow-up.

That night, she presented to the emergency department with a fever of 39.4°C (103.0°F), nausea, headache, and dry cough. The pain had radiated into the lower and middle portions of the back. Her complete blood count and urinalysis were within normal limits, and a urine pregnancy test was negative. Blood cultures were drawn and she was sent home.

The next day, blood cultures grew gram-negative rods. She was admitted to the hospital with a provisional diagnosis of sciatica and pyelonephritis, and she was started on levofloxacin. At admission, her vitals were as follows: blood pressure, 100/60 mm Hg; pulse rate, 96 beats per minute; and temperature, 39.8°C (103.7°F). She was in moderate distress. Her abdomen was soft and nontender with no organomegaly. She had positive psoas and obturator signs. The blood cultures grew Salmonella sensitive to ciprofloxacin and gentamicin. The patient had not traveled recently and had no diarrhea. She denied eating any unusual foods, but later revealed working in a fast food restaurant where she handled raw chicken and beef with her bare hands.

Lumbar spine and magnetic resonance imaging (MRI) of the hip were read as "minimal disk herniation of L4-L5, pelvic organs normal, bladder slightly distended, and scant increase of fluid in the left hip joint." I asked a senior radiologist to review the hip MRI. He said, "The psoas muscle is lighting up like a light bulb." As I spoke with him, I searched PubMed for the terms "psoas" and "Salmonella." I found seven references^1-6 to Salmonella psoas myositis and sacroiliac osteomyelitis. These diagnoses explained the patient's symptoms, signs, and MRI findings.

The patient improved. A bone scan showed osteomyelitis of the left sacroiliac joint and inflammation of multiple muscles. This was confirmed by a tagged white blood cell scan. The patient was discharged on the seventh hospital day, and ciprofloxacin was continued for six weeks, by which time she had fully recovered.

This case illustrates the continued importance of bedside diagnostic skills, the need to consider the clinical context in interpreting imaging studies, and the key roles that the family physician and the Internet can play in the care of a patient with a complex illness.

DANIEL L. WOLK, M.D.
101 S. Bryn Mawr Avenue-Ste 120
Bryn Mawr, PA 19010-3120

REFERENCES

1. Collazos J, Mayo J, Martinez E, Blanco MS. Comparison of the clinical and laboratory features of muscle infections caused by Salmonella and those caused by other pathogens. J Infect Chemother 2001;7:169-74.
2. Baccaro FG. Primary psoas abscess due to Salmonella typhi. MedGenMed 1999;10:E16.
3. Lin MF, Lau YJ, Hu BS, Shi ZY, Lin YH. Pyogenic psoas abscess: analysis of 27 cases. J Microbiol Immunol Infect 1999;32:261-8.
4. Collazos J, Mayo J, Martinez E, Blanco MS. Muscle infections caused by Salmonella species: case report and review. Clin Infect Dis 1999;29:673-7.
5. Wysoki MG, Angeid-Backman E, Izes BA. Iliopsoas myositis mimicking appendicitis: MRI diagnosis. Skeletal Radiol 1997;26:316-8.
6. Lortholary O, Jarrousse B, Attali P, Hoang JM, Brauner M, Guillevin L. Psoas pyomyositis as a late complication of typhoid fever. Clin Infect Dis 1995; 21:1049-50.

Punch Biopsies Are Not the Way to Diagnose Melanoma

TO THE EDITOR: As a family physician turned dermatologist, I always read with interest the articles in American Family Physician that deal with the diagnosis and management of skin diseases. I enjoyed reading "Punch Biopsy of the Skin,"¹ for its discussion of punch biopsy indication and techniques. I found the article to be informative and well presented, with the exception of the described use of punch biopsy in the diagnosis of melanoma. The pitfalls related to the interpretation of a punch biopsy, with the limited length of skin available to examine, have been previously discussed in American Family Physician.² Recent data show that, of the three basic techniques of suspected melanoma biopsy--excision, scoop shave, and punch--punch biopsy is the most likely to yield an uncertain result.³ This applies to determining the depth of melanoma, on which prognosis and definitive therapy is based, and correctly diagnosing the lesion. The only exception is the punch biopsy of a lesion that fits entirely within the punch.

"Doing the math" explains the difficulty. A suspicious lesion 1 cm in diameter has an area of 0.79 cm². A "representative" 4-mm punch will sample 0.13 cm², which is only 16 percent of the surface of the lesion. Three 2-mm punches, sometimes advocated for large facial lesions, sample less than 0.1 cm² combined. Furthermore, the advice that one can sample the most suspicious part of the lesion is flawed because the most papular component of a melanoma may indeed represent the thickest part of the cancer or may, instead, be the benign melanocytic lesion out of which the melanoma arose. Since melanoma is diagnosed more by histologic appearance of what the melanocytes are doing than by what any individual melanocyte looks like, the most diagnostic portion of a lesion may be the darkest part, the lightest part, the amelanotic part, or the regressing part. Incorrectly determining the true depth and thickness of the melanoma may lead to inadequate therapy, but the real hazard is completely missing the diagnosis and allowing a life-threatening cancer to remain while the patient has been reassured that "everything is okay."

Prognosis and definitive therapy are determined by tumor depth and thickness, and the best way to get this information remains a conservative excision of the entirety of the suspicious lesion. If the lesion is in a cosmetically sensitive area or is too large to do this, the largest incisional biopsy possible should be performed. The risk of incomplete information still exists with this technique, but at least much more tissue is available to examine than is obtained with a standard punch. Incomplete excision of a melanoma does not encourage metastatic spread or more aggressive biologic behavior. Thin lesions of limited size may be scoop-shaved by an experienced operator, but even this procedure is not recommended if a melanoma appears deeply invasive or ulcerated.

JEFFREY J. MEFFERT, M.D.
105 Cas Hills
San Antonio, TX 78213

REFERENCES

1. Zuber TJ. Punch biopsy of the skin. Am Fam Physician 2002;65:1155-8.
2. Meffert JJ. Lentigo maligna melanoma. Am Fam Physician 2000;61:3385-6.
3. Pariser RJ, Divers A, Nassar A. The relationship between biopsy technique and uncertainty in the histopathologic diagnosis of melanoma. Dermatol Online J 1999;5:4.

The opinions and assertions contained herein are the private views of the author and are not to be construed as official or as reflecting the views of the Army Medical Department, the Army Service at large, the Department of Defense, or other departments of the U.S. Government.

IN REPLY: Dr. Meffert raises several important issues concerning the shortcomings of punch biopsy. When dealing with suspicious melanocytic lesions, excisional biopsy is generally preferable. For situations in which excisional biopsy cannot be performed, incisional biopsy is a good second choice.

The chapter¹ and subsequent article² on punch biopsy listed one of the indications for the procedure as establishing the diagnosis of melanoma. While punch biopsy is usually not the procedure of choice, it continues to be used by many physicians. Diagnosis of melanocytic lesions in certain sites (nailbed) may be best accomplished by punch technique in many primary care practices. Punch biopsy technique using larger (6-mm) trephines can actually achieve complete excision of a lesion. National guidelines^3,4 have recognized the use of punch technique in diagnosing melanoma. Other specialties have also recognized punch biopsy as a method to diagnose cutaneous malignancy.⁵

Many family physicians receive instruction from their community subspecialists not to touch melanocytic lesions; they are warned that biopsy within a lesion (incisional or punch) could cause spread of a melanoma. Dr. Meffert correctly notes that biopsy does not promote the spread of a lesion.⁶ Family physicians were also warned not to touch lesions so that sentinel lymph node testing could be accomplished. We now know that sentinel lymph node procedures can be accurately performed as a secondary procedure. Family physicians should not be discouraged from participating in diagnosing melanoma.

The incidence of melanoma is increasing rapidly in the United States. Biopsy should be performed on suspicious lesions as soon as possible. If the family physician is not comfortable or skilled in biopsy of larger excisions, referral is appropriate; however, this may cause significant delay. Punch biopsy or multiple punch biopsies could possibly facilitate rapid diagnosis for some patients.

Punch biopsy for large melanocytic lesions does have pitfalls. False-negative results can occur using small area biopsies (2-mm or 3-mm punches). Trying to select the most significant area within a large lesion to biopsy can also lead to clinical inaccuracies. A referred patient recently had an acral lentiginous melanoma whose initial single punch biopsy was read as negative. While multiple biopsies could overcome some of the limitations associated with a single punch biopsy, multiple biopsies also have shortcomings. Further intervention or referral should be considered when a negative interpretation is provided for a punch biopsy specimen.

I urge physicians to perform an excisional or incisional biopsy whenever possible. However, I cannot agree with the conclusion that punch biopsies should never be performed on melanocytic lesions. In some practices, punch biopsy remains the only diagnostic option for a physician. Dr. Meffert correctly identifies the limitations of the punch technique and the problems with relying on a negative punch histologic interpretation; however, early biopsy is clearly what is needed, and family physicians must be involved if we are to reverse the increasing tide of melanoma deaths in the United States. We should not create additional barriers for family physicians that keep them from participating in this important public health problem.

THOMAS J. ZUBER, M.D.
Atlanta, GA 30307

REFERENCES

1. Zuber TJ. Punch biopsy of the skin. In: Zuber TJ. Office procedures. Baltimore: Lippincott Williams & Wilkins, 1999.
2. Zuber TJ. Punch biopsy of the skin. Am Fam Physician 2002;65:1155-8.
3. Guidelines of care for malignant melanoma. Committee on Guidelines of Care. Task Force on Malignant Melanoma. J Am Acad Dermatol 1993; 28:638-41.
4. NIH Consensus conference. Diagnosis and treatment of early melanoma. JAMA 1992;268:1314-9.
5. Padgett JK, Hendrix JD, Jr. Cutaneous malignancies and their management. Otolaryngol Clin North Am 2001;34: 523-53.
6. Bong JL, Herd RM, Hunter JA. Incisional biopsy and melanoma prognosis. J Am Acad Dermatol 2002; 46:690-4.