Case Presentation and Discussion

Leg Mass

Liborio I. Soledad, Jr., MD
Year I Surgery Resident
GSI, Department of Surgery, Philippine General Hospital
1999

Note 1: The surgical resident was asked to read the self-instructional program entitled "Management of a Surgical Patient" written by the undersigned and used it as a guide to present and discuss the case. This is his output. My comments are seen in the "text areas" within and at the end of the manuscript.

Note 2: I welcome reactions not only from Dr. Liborio Soledad, Jr. but also from readers. Forms are provided at the end of the manuscript for this purpose or email can be used.

Reynaldo O. Joson, MD, MHA, MHPEd, MS Surg
Facilitator

Case Presentation and Discussion

We are presented with a 36/F, who came in for a mass on her right leg. Her story dates 2 months back when she first noted a small nodule on the lateral aspect of her right leg. She ignored this and did not seek consult until it gradually increased in size. There were no associated signs and symptoms noted with the mass.

(+) 5 x 4 cm mass, hard, non-tender, non-movable, non-erythematous, lateral aspect, right leg. See Illustration.

CLINICAL DIAGNOSIS

Arriving at a working diagnosis is the first thing that I must do. And in doing so, I must check and confirm if there really is a mass on her right leg. Having done so, I now try to determine the tissue of origin. A leg mass can come from any of the following tissues:

1. skin
2. muscle
3. bone
4. fat

I can say that the mass is from the skin if there are evidences of skin lesions or breaks. Looking at the patient, I see none. I can therefore say that the mass is underneath the skin and is most likely NOT a skin tumor.

I can also say that the mass may be coming from bone tissue. If so, the mass should feel bony hard. I palpate for the mass and feel that the mass is not bony hard. I can therefore say that the mass is most likely NOT bone in origin.

I have now reduced the impression to a right leg mass, underneath the skin, non-bony. I am now left with two possible tissues of origin:

1. muscle
2. fat

I can say that the mass is of adipose tissue in origin if I feel that it is soft and non-tender. The mass feels hard and is not soft as expected of a fat-containing mass. I can therefore say that the mass is most likely NOT of fat tissue in origin.

How about the depth of the mass beneath the skin level? A subcutaneous mass is more superficial than a muscular mass. The depth, if properly determined, may be more reliable than the consistency of the mass. It is true that adipose tissues are usually soft. However, it can also be hard say as a result of chronic infection and fibrosis.

I am now left with one choice, muscle. To strengthen my guess, I try to find evidences that point to muscle as tissue of origin. The mass is underneath the skin, non-hard, non-bony, and slightly movable. On further examination, the mass seems to move with flexion of leg muscles. Satisfying these, I am more confident in saying that the mass IS most likely muscle in origin. I now go on to determine whether the mass is malignant, non-malignant, or inflammatory.

In the previous paragraph, you mentioned the mass was hard. Now, you are saying it is non-hard. Which is correct? As I said earlier, the depth is an important initial cue to determine whether the mass is subcutaneous fat or muscular in origin. The mass moving with flexion of the leg muscles is another important cue.

If the mass were inflammatory, it would show the classic signs of inflammation, like redness, warmth, pain, and loss of function. All of these are not found in the patient. The mass is not tender, not warm, with normal skin color, and the leg is functioning normally. Thus, the mass is most likely NOT inflammatory. The mass could either be malignant or benign. Evidences that point to a malignant pathology are the following: rapid growth (2 mos), hard, fixed or non-movable, young patient, and high index of suspicion. My working diagnosis now would be: Right leg mass, muscular, probably malignant. My secondary diagnosis is: Right leg mass, muscular, probably benign.

Since you are thinking of a tumor of a muscular origin, you are now considering a soft tissue tumor. After finding no cue for inflammation, you are now trying to decide whether the mass is a sarcoma or not. To decide whether the tumor is a sarcoma or not, you first look for cues for malignancy or sarcoma. This brings us to the questions, are there, if there are, what are the reliable clinical cues for soft tissue sarcoma? So what are the reliable clinical cues for sarcoma? Most soft tissue sarcomas are not hard. They just feel hard because they are tense. Fixation may be reliable cue if present. Don't use a high index of suspicion per se as a basis. You spell out the basis for suspecting sarcoma - fixed. Search the literature for the reliable clinical parameters. Personally, I don't think rapid growth of 2 months is a reliable cue, nor young patient. I mentioned the hard consistency already. At the moment, until invalidated by evidences, I use the following processes in suspecting soft tissue sarcoma in a soft tissue mass which is not fixed and without associated distant metastasis - a soft tissue mass (nonskin, nonosseous mass, which does not have the characteristic patterns of a sebaceous or epidermal cyst and lipoma.

PARACLINICAL DIAGNOSTIC PROCEDURE

My next question is whether I should employ the aid of a paraclinical diagnostic procedure. This would confirm or make my diagnosis more clear. This would all depend on my mode of treatment. If confirming my diagnosis would affect my treatment of choice, then I have to make use of a diagnostic procedure. Reviewing the case, mode of tumor removal would be different in a benign as compared to a malignancy. I therefore decide in using added assistance in diagnosis.

How about the initial process in determining need for paraclinical diagnostic procedure, which is degree of certainty of the clinical diagnosis? If there are reliable clinical parameters for a soft tissue sarcoma and these are present in the patient, then you can say you are quite certain of your diagnosis that you do not have to go for paraclinical diagnostic procedure. Are there reliable clinical parameters for soft tissue sarcoma and are these present? The difference in the mode of treatment for the primary and secondary diagnoses is the other process you use in determining the need for a paraclinical diagnostic procedure. This you mentioned in your discussion. Do not forget the first process!

Choosing which diagnostic procedure comes next. What I need is a cytologic/histologic aid. Most cost-effective would be a Fine-needle aspiration of the mass. This would give us information as to a tissue source and whether the mass is malignant or not. Radiologic examinations would be a non-priority. An incisional biopsy would give us a higher yield but looking at the mass, it would need extirpation eventually.

Be systematic in your decision-making for the selection of the paraclinical diagnostic procedure. Spell out your objective first. You want to be more definite of your primary clinical diagnosis which is soft tissue sarcoma. In your discussion, you mentioned three options, namely, fine-needle aspiration biopsy, incisional biopsy, and x-rays. You have to show the comparison of the three options, in terms of benefit, risk, cost and availability. Benefitwise, incisional biopsy is the best among the three because it provides a direct evidence and it will have a yield of as high as 98%. Needle biopsy also provides direct evidence or information and the yield is not as high as that of an incisional biopsy. If the yield is 90%, then it is acceptable. X-ray is an imaging technique, therefore can only provide indirect evidence. Thus, among the three options, it ranks lowest in terms of benefit. Risk wise, needle biopsy is better than open biopsy - less invasive. Cost wise, needle biopsy is better than open biopsy. Availability wise, all are readily available. You can only say the needle biopsy is the most cost-effective paraclinical diagnostic procedure if you can show that its diagnostic yield for soft tissue sarcoma is acceptable. Is it?

An FNAB was done in the patient with the following findings: Spindle cell carcinoma.

This result is open to question. Can needle biopsy yield a diagnosis of "spindle cell carcinoma?" Needle biopsy is basically a cytologic study. Expectation will be presence or absence of malignant cells. Remember, I raise the issue earlier whether needle biopsy will have an acceptable diagnostic yield? Research on this.

My choice of diagnostic procedure has now confirmed my diagnosis. My working diagnosis now would be: Spindle cell carcinoma, right leg.

TREATMENT

The next step is deciding or choosing the appropriate mode of treatment. Given that the mass is malignant, I have no choice but to excise the mass together with an adequate margin of normal tissue - wide excision.

Avoid making statement that you have NO CHOICE at least not before you presented all the different options and justify that you have to do an operation. Compare operation with other treatment modality based on benefit, risk, cost, and availability.

If the mass turned out to be benign during our diagnosis, we could employ simple excision. This is the benefit obtained from doing the aspiration biopsy. An adequate margin of normal would be included in the excision to avoid local recurrences and to ensure proper and good wound healing. Providing medications would prove to be futile in this case.

Spell out your objective in the treatment plan such to completely extirpate the tumor with adequate margin and to close the resultant skin defect with least morbidity. After spelling out your objective, choose the best surgical procedure. Wide excision with primary skin closure vs wide excision with skin graft or with flaps?

PRE-OPERATIVE PROCEDURE

Having decided on the mode of treatment, I will now explain to the patient, and her relatives the entire operative procedure together with the risks and possible outcomes. This is important so the patient would feel confident and would be more prepared. Providing support psychologically and psychosocially would also be employed.

I should also be wary of the possible risks that would affect the patient. Being so, I must first screen the patient from other diseases to avoid unlikely outcomes. Securing consent must be done prior to the procedure. This is obtained most often after the patient has understood the surgical procedure. After having done so, I must secure the necessary needs so I prescribe to them and allow sufficient time for procurement.

INTRA-OPERATIVE MANAGEMENT

The patient would undergo excision of the mass, to include normal tissue around it. The incision would be elliptical to ensure adequate closure of the skin.

"The incision would be elliptical to ensure adequate closure of the skin." What do you mean? Between linear and elliptical incision, which one will ensure adequate skin closure? In elliptical incision, you remove skin. In linear incision, you don't. In the leg, when you do elliptical incision, there is a potential problem of skin closure. In the leg, a vertical elliptical incision has a better chance of skin closure that a transverse elliptical incision.

A margin of around 2-3cm of normal tissue would be included to make sure adequate removal of malignant tissue is done. Bleeding vessels would be ligated. Would defect would be closed using absorbable sutures. Sterile dressing would be applied.

POST-OPERATIVE MANAGEMENT

Immediately post-operatively, the patient would be monitored closely wherein her viatl signs would be measured on a regular basis as well as to apply wound care by observing and watching out for bleeding. Patient would be comforted with analgesics and cool environment. Once patient is stable and without anesthesia, she can be transported back to the main wards.

Once in the wards, wound care would be continued as to avoid infection. If the patient remains to be stable, she can be sent home with proper instructions regarding wound care and follow-up. It is important to educate care takers so proper wound care is done.

FOLLOW-UP

I will instruct the patient to visit on regular follow-ups to make sure proper would care is made at home. Also this would give her the chance to learn and confirm the diagnosis based on histopathologic examinations. One confirmed, proper advise and counseling can be employed.

Look up for reliable cues for soft tissue sarcoma.

Suggestions to Dr. Liborio Soledad on improvement of case presentation and discussion:

1. Refer to the format of a general case presentation and discussion.

2. Refer to the format used in "Management of Surgical Patient."

3. Use the Evaluation Form below as a guide.

Reactions from Dr. Liborio Soledad, Jr.

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you can email me your reactions.)

rjoson@pacific.net.ph

Questions and Comments from Readers

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you can email me your questions and comments.)

rjoson@pacific.net.ph

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