Subclinical Infiltration of Basal Cell Carcinoma in Asian Patients: Assessment after Mohs Micrographic Surgery

Background

Several differences in basal cell carcinomas (BCCs) were found, according to the ethnic group; for example, pigmented BCCs was more common in Asian or Hispanic patients. However, there are few reports on the subclinical extension of the BCC in Asian patients.

Objective

The aim of this study was to evaluate the subclinical infiltration of the basal cell carcinoma in Asian patients.

Methods

All patients with BCC who visited the department of dermatology at Korea University Ansan Hospital were treated with Mohs micrographic surgery. In 81 patients, 83 tumors of BCC were completely eradicated by Mohs micrographic surgery (MMS) from April 2001 to August 2008, and were reviewed in this study. Information recorded included the total margin and the number of stages of Mohs micrographic surgery, anatomic location, tumor size, presence of pigmentation, clinical type, and pathological subtype. We divided the clinical types into nodular, ulcerated, and pigmented, and the pathological types into nodular, micronodular, morpheaform, and adenoid. The BCC was of pigmented type if pigmentation covered more than 25% of the tumor, regardless of whether pigmentation was distinct, or if there was apparent pigmentation that covered more than 10% of the tumor.

Results

The nose and cheek were the most common sites requiring more than one stage of surgery. In tumors smaller than 1 cm, 91.7% required only one stage of excision, compared with 60.6% in tumors larger than 1 cm. More than two Mohs stages were required in 25% of non-ulcerated BCCs and in 46.2% of ulcerated BCCs. Sixty eight percent of pigmented BCCs required only one stage of Mohs micrographic surgery. In cases of non-pigmented BCCs, only 45% required one Mohs stage. More than one Mohs stage was required in 19.2% of non-aggressive BCCs and in 42.9% of aggressive BCCs.

Conclusion

Subclinical infiltration differed between the two groups according to the size of the BCC (1 cm threshold) and most of the BCCs were located in the head and neck area. Considering this result, indication for MMS can be extended for BCCs larger than 1 cm in Asian patients. Ulcerated BCCs required more Mohs stages than non-ulcerated BCCs. Pigmented BCCs might show lesser subclinical infiltration than non-pigmented BCCs. Aggressive pathological subtypes showed more subclinical infiltration than the non-aggressive types; however, after evaluation of the border that was excised with MMS, mixed histologic types were found to be more frequent than generally accepted. Therefore, we consider that, when planning surgery, dermatologists should not place too much confidence in the pathologic subtypes identified by biopsy.     

Recurrent basal cell carcinoma after incomplete resection

BACKGROUND: Because the probability of basal cell carcinoma (BCC) recurrence was thought to be 30% to 50%, surgical tradition became not to perform additional resection when the margin was positive. OBJECTIVE: To determine whether there is an association among age or sex of the patient, anatomic location, histologic type, or reconstructive procedures and the signs and symptoms of the recurrence, interval between incomplete resection and Mohs micrographic surgery (MMS), or extent of MMS resection. DESIGN: During 20 years, all patients with incompletely excised BCC of the head referred for MMS were sequentially prospectively accrued into the cohort. SETTING: An outpatient MMS practice. PATIENTS: Nine hundred ninety-four patients. MAIN OUTCOME MEASURES: Interval to tumor recurrence, interval to MMS, and extent of MMS as determined by mean surface area resected, depth of resection, and number of tumor nests. RESULTS: The interval to signs or symptoms of recurrence and to MMS from incomplete resection was greater for men, patients older than 65 years, those having a tumor on the nose or cheek, those with aggressive or fibrosing BCC, and those who underwent flap reconstruction (P =.001). The extent of MMS resection was greater for those with flap and split-thickness skin graft repairs. The number of tumor nests identified by MMS was significantly greater in those treated with split-thickness skin graft and flap (P =.001). CONCLUSION: Because it is more difficult to control recurrent BCC, treating tumor remaining at the margin of resection in the immediate postoperative period could result in less extensive surgery.     

Clinicopathological factors influencing the number of stages of Mohs surgery for basal cell carcinoma

BackgroundMohs Micrographic Surgery (MMS) is commonly used to treat high-risk basal cell carcinoma (BCC).ObjectivesCorrelate clinicopathologic preoperative features with the number of MMS stages (primary endpoint) and margins (secondary endpoint) required for BCC complete excision.MethodsWe retrospectively analyzed BCCs treated by MMS in a 2-year period at the study’s institution. Variables studied included the patient gender, age, immune status, lesion size, location, if it was a primary, recurrent, or persistent tumor, histopathologic characteristics, number of surgical stages, and amount of tissue excised.Results116 BCCs were included. The majority (61.2%, n = 71) required a single-stage surgery for complete clearance, requiring a final margins of 3.11 ± 2.35 mm. Statistically significant differences between locations in different high-risk areas (periocular, perioral, nose, ear) and the number of MMS stages required for complete excision (p = 0.025) were found, with periocular tumours requiring the highest mean of stages (2.29 ± 0.95). An aggressive histopathology significantly influenced the number of MMS stages (p = 0.012). Any significant relation between clinicopathological features and variation in the final surgical margins was found, just certain tendencies (male patients, persistent tumor, periocular location, and high-risk histopathological tumors required larger margins). Neither patient age or tumor dimension correlated significantly with both number of MMS stages and final surgical margins.Study limitationsLimitations of this study include its single-center nature with a small sample size, which limits the value of conclusions.ConclusionMain factors related to a greater number of MMS stages were periocular location and high-risk histopathological subtype of the tumor.     

Mohs micrographic surgery for the treatment of melanoma

For melanoma treatment, the primary goal is complete removal with histologically negative margins. Mohs micrographic surgery (MMS) has been extensively used and studied for the treatment of nonmelanoma skin cancer, particularly at sites where tissue conservation is vital. The use of MMS for melanoma treatment has yet to become widely accepted owing to difficulties in histologic interpretation, among other factors. MMS may offer lower recurrence rates and improved survival when compared with historical controls for standard excision. Continued advances in MMS technique and immunohistochemical staining have allowed the technique to gain further support.     

Mohs micrographic surgery for the treatment of malignant melanoma

Mohs micrographic surgery (MMS) is very successful in the treatment of nonmelanoma skin cancer. Examining 100% of the margin using MMS improves cure rates. This method has obvious appeal in treating melanoma. Evaluating the lateral margins of melanomas using frozen tissue sections is complicated. Some studies have shown that basic frozen sections can be accurate in margin evaluation, but others have shown that they are unreliable. The use of immunostains on frozen sections is one method that may make the analysis of frozen sections more accurate. Other modifications, including the use of rush paraffin sections in lieu of frozen sections, “slow Mohs,” have also been reported. Although the role of MMS in the treatment of melanoma has been controversial, multiple reports using all of the above-mentioned methods have shown great success. Mohs micrographic surgery has a role in the management of melanoma, especially for lesions with poorly defined margins or for those located in areas where tissue conservation is critical.     

It's time for Mohs: Micrographic surgery for the treatment of high‐risk basal cell carcinomas of the head and neck regions

Basal cell carcinoma (BCC) is the most common variety of non‐melanoma skin cancer and its incidence is increasing worldwide. The centrofacial sites (area H) are considered a high‐risk factor for BCC local recurrence. Mohs micrographic surgery (MMS) is a technique that allows intraoperative microscopic control of the surgical margins and is a good treatment option when tissue conservation is required for esthetic or functional reasons or for high‐risk lesions. The present study aimed to evaluate the recurrence rate of head and neck high‐risk BCCs comparing MMS vs conventional surgical excision. Clinical data of patients diagnosed from September 2014 to March 2017, referring to the Dermatology Unit of the Policlinico Sant'Orsola‐Malpighi, University of Bologna, were retrospectively evaluated (285 treated with MMS and 378 treated with traditional surgery). Of the 285 patients treated with MMS, 9 experienced a recurrence (3.1%). Of the 378 patients treated with traditional surgery, 53 relapsed (14%), 13 of whom presented residual tumor on the deep or lateral margins of the main surgical specimen. Our study confirms the trend reported in the literature that MMS represents the best treatment option for high‐risk BCCs arising in the head and neck region or presenting as a recurrence (P < .00001). Many more MMS centers and more trained dermatologists are needed worldwide in order to deal with the increasing number of BCC diagnosed every year.     

Presence of residual basal cell carcinoma in re-excised specimens is more probable when deep and lateral margins were positive

In order to quantify presence of residual BCC in patients with histologic positive margins after the first excison and to correlate the presence of residual tumor in re‐excised lesions with the location of the positive margin on the first excision, a retrospective evaluation of 2053 surgically treated BCC was performed. Only 38.3% of the re‐excised lesions showed residual tumor. In the group of re‐excised lesions where residual BCC was found, 13% had lateral positive margin in the first excision, 39% had deep positive margin and 48% had both lateral and deep positive margins. In the group of re‐excised lesions where no residual BCC was found, 49% of the primary excised lesions had lateral positive margin, 32% had deep positive margin and 19% had both deep and lateral positive margins. The association between residual tumor and positive margins was statistically significant (p = 0.01). Our findings confirm that presence of residual tumour is more likely when both lateral and deep margins are compromised.     

Mohs surgery histopathology concordance in Australia

Background: Mohs micrographic surgery is an important technique for dealing with difficult non‐melanoma skin cancers. The ability of the Mohs surgeon to correctly interpret the histopathology is crucial to the practice of this surgery. This study sought to assess the concordance between a Mohs surgeon and a dermatopathologist in the reading of Mohs section histopathology slides. Methods: This study was a retrospective study of Mohs frozen section histopathology slides of patients from a private Mohs practice. The slides were provided for assessment by a dermatopathologist who had to interpret the histopathology and mark on a Mohs map the location of the tumour. Results: We demonstrate a 95% agreement between the Mohs surgeon and the dermatopathologist in the interpretation of Mohs frozen section histopathology slides. Conclusion: An Australian Mohs surgeon is capable of correctly identifying and interpreting histopathology in non‐melanoma skin cancers, and this compares favourably to an overseas study.     

Cost-effectiveness of Mohs Micrographic Surgery vs Surgical Excision for Basal Cell Carcinoma of the Face

OBJECTIVE: To assess the cost-effectiveness of Mohs micrographic surgery (MMS) compared with the surgical excision for both primary and recurrent basal cell carcinoma (BCC). DESIGN: A cost-effectiveness study performed alongside a prospective randomized clinical trial in which MMS was compared with surgical excision. SETTING: The study was carried out from 1999 to 2002 at the dermatology outpatient clinic of the University Hospital Maastricht, Maastricht, The Netherlands. PARTICIPANTS: A total of 408 primary (374 patients) and 204 recurrent (191 patients) cases of facial BCC were included. MAIN OUTCOME MEASURES: The mean total treatment costs of MMS and surgical excision for both primary and recurrent BCC and the incremental cost-effectiveness ratio, calculated as the difference in costs between MMS and surgical excision divided by their difference in effectiveness. The resulting ratio is defined as the incremental costs of MMS compared with surgical excision to prevent 1 additional recurrence. RESULTS: Compared with surgical excision, the total treatment costs of MMS are significantly higher (cost difference: primary BCC, 254 euros; 95% confidence interval, 181-324 euros; recurrent BCC, 249 euros; 95% confidence interval, 175-323 euros). For primary BCC, the incremental cost-effectiveness ratio was 29,231 euros, while the ratio for recurrent BCC amounted to 8094 euros. The acceptability curves showed that for these ratios, the probability of MMS being more cost-effective than surgical excision never reached 50%. CONCLUSIONS: At present, it does not seem cost-effective to introduce MMS on a large scale for both primary and recurrent BCC. However, because a 5-year period is normally required to determine definite recurrence rates, it is possible that MMS may become a cost-effective treatment for recurrent BCC.     

Immunohistochemical staining of lentigo maligna during Mohs micrographic surgery using MART-1.

BACKGROUND: Lentigo maligna (LM) often displays extensive subclinical spread. Mohs micrographic surgery (MMS) has been proposed to help delineate the true histologic margin; however, visualizing atypical melanocytes on frozen section is challenging and often requires confirmatory permanent paraffin sections. OBJECTIVE: Our aim was to use a monoclonal antibody to rapidly stain frozen sections during MMS to facilitate better visualization of atypical melanocytes. METHODS: Frozen sections of LM during MMS were stained with MART-1 (melanoma antigen recognized by T cells) and compared with paraffin-embedded sections. RESULTS: We found 100% correlation between frozen sections stained with MART-1 and paraffin-embedded sections. CONCLUSIONS: Atypical melanocytes can be better visualized on frozen sections of LM by using MART-1 rather than hematoxylin and eosin. This allows for easier identification during MMS and better chance of complete removal of LM lesions.     

Cutaneous lip tumours treated with Mohs micrographic surgery: clinical features and surgical outcome

BACKGROUND: The Australian Mohs micrographic surgery (MMS) database was initiated in 1993 by the Skin and Cancer Foundation Australia (SCFA) with the aim of collecting prospective data, and involved all Mohs surgeons in the country. OBJECTIVES: To present a large series of patients with cutaneous lip tumours treated with MMS in Australia between 1993 and 2002. METHODS: This prospective multicentre case series included all patients with cutaneous lip tumours who were monitored by the SCFA. The main outcome measures were patient demographics, reason for referral, duration of tumour, site, preoperative tumour size and postoperative defect size, recurrences prior to MMS, histological subtypes, perineural invasion and 5-year recurrence after MMS. RESULTS: There were 581 patients (66.1% women and 33.9% men, P < 0.0001) with a mean +/- SD age of 58 +/- 15 years. The upper lip was the most common site involved (81.1%). Basal cell carcinoma (BCC) was diagnosed in 82.3%, squamous cell carcinoma (SCC) in 16.5%, Bowen's disease (BD) in 0.7% and microcystic adnexal carcinoma (MAC) in 0.5% of cases. BCC was more common on the upper lip and in women, whereas SCC was more common on the lower lip and in men (P < 0.0001). Most upper lip tumours occurred in women (75.4%), whereas most lower lip tumours occurred in men (73.6%). SCC was associated with a larger tumour and postoperative defect size compared with the other tumours. The 5-year recurrence for BCC was 3.0%, and there were no cases of recurrence for SCC, BD or MAC. CONCLUSIONS: BCC was the most common cutaneous lip tumour managed by MMS, and was significantly more common on the upper lip and in women. The low 5-year recurrence rate emphasizes the importance of margin-controlled excision.     

Imiquimod 5% cream as pretreatment of Mohs micrographic surgery for nodular basal cell carcinoma in the face: a prospective randomized controlled study

Background Imiquimod 5% cream can reduce or clear superficial and small nodular basal cell carcinoma (BCC). It could be used as a pretreatment of Mohs micrographic surgery (MMS) to decrease defect size. Objectives To study if a pretreatment with imiquimod 5% cream decreases defect size after MMS. In addition, to study the effect on the number of Mohs stages and reconstruction time. Methods Seventy patients aged >18 years with a primary nodular BCC in the face were included. The imiquimod group used imiquimod 5% cream for 4 weeks, before MMS. The control group was treated with MMS only. Tumour and defect sizes were measured. We noted the number of Mohs stages, reconstruction time and side‐effects. Results The median percentage increase in area from tumour size at baseline to the post‐MMS defect for the imiquimod group was significantly less compared with the control group, 50% vs. 147% (P < 0·001). A tendency towards fewer Mohs stages in the imiquimod group was observed and the reconstruction time was significantly shorter in this group (P = 0·01). Conclusions Imiquimod 5% cream as pretreatment of MMS significantly reduced the tumour size in primary nodular BCC and reduced the surgical defect size. Further research is necessary to investigate cost‐effectiveness.     

Correlation Between Incisional Biopsy Histological Subtype and a Mohs Surgery Specimen for Nonmelanoma Skin Cancer

Background

Histological diagnosis of a clinically suspected nonmelanoma skin cancer (NMSC) is recommended before treatment. For NMSC, concordance between the histological subtype of the preoperative biopsy and the excision specimen of basal cell carcinoma (BCC) has been reported to range from 10% to 81%. No large study on the concordance between NMSC histology seen in a preoperative biopsy with the following tumour specimen from Mohs micrographic surgery (MMS) has been performed in a Latin American population.

Mohs micrographic surgery for repeat excision of basal cell carcinomas on the head with positive margins

BackgroundThere is debate in the literature regarding the management of basal cell carcinoma following excision with positive surgical margins. While in some cases recurrence is not observed even after many years of follow-up, those in which recurrence does occur are at an increased risk of complications.Factors may exist that help to choose the best therapeutic approach for basal cell carcinomas on the head in which positive margins are observed following excision.Material and methodsA total of 46 patients were selected who had been treated by Mohs micrographic surgery as a result of positive surgical margins being present following previous tumor excision. The factors associated with the absence of tumor nests and the occurrence of negative margins following a single Mohs stage were analyzed.ResultsNo associations were observed with sex, tumor size, affected margin (lateral, deep, or both), time since diagnosis, number of previous treatments, histological type, or tumor site. There was a certain trend towards more frequent identification of tumor nests when both surgical margins were affected and towards a requirement for a single Mohs stage in tumors less than 1.2 cm and in which less than 5 years had elapsed since diagnosis.ConclusionsConclusive data are unavailable with which to define cases in which repeat excision is necessary or those in which conventional excision could be sufficient. The best option for the treatment of these tumors is Mohs micrographic surgery, although conventional excision could be reasonable in small tumors located at low-risk sites and in which long periods have not elapsed since diagnosis.     

Basal cell carcinoma of the head region: therapeutical results of 350 lesions treated with Mohs micrographic surgery

Background Basal cell carcinoma (BCC) is a non‐melanocytic skin tumour with a high risk of recurrence after incomplete treatment, especially the aggressive subtypes (basosquamous, micronodular and morphea BCC). The percentage of recurrence also depends on the anatomical site of the tumour. Nose–cheek fold, paranasal fold, retroauricular fold and internal canthus are considered to be critical sites. Objective The aim of this study was to report on recurrence rates for BCC treated with Mohs micrographic surgery (MMS). Material and Methods We retrospectively studied 350 BCCs of the head region treated with MMS. Results were analysed with chi‐squared test and Fisher test and were considered significant when P value was ≤0.05. Results In our study, the percentage of BCC recurrence rate after MMS was of 3.4% for primary BCC and 4.9% for recurrent BCC; these were similar to the recurrence rates reported in the literature. Conclusions Low recurrence rate can be achieved when treated with MMS; it is the treatment of choice for many BCC of the head. Aggressive histopathological subtypes, critical head sites and recurrence after incomplete excision are the most important indications for MMS.     

Pigmented basal cell carcinoma: investigation of 70 cases.

BACKGROUND: Pigmented basal cell carcinoma (PBCC) is a clinical and histologic variant of BCC. OBJECTIVE: Our purpose was to identify the histologic subtypes of BCC that were most often associated with pigment and to determine whether this correlated with outcome after excision. METHODS: A series of PBCC was identified and the histologic subtype noted. Margins of all excisions were examined for residual tumor. These results were then compared with a series of nonpigmented BCCs. RESULTS: In a series of 1039 consecutive BCCs, 70 (6.7%) contained pigment. The histologic growth pattern most frequently associated with pigment was the nodular/micronodular pattern (12.4%) followed by the nodular (7.7%), superficial (7.2%), micronodular (4.0%), and the nodular/micronodular/infiltrative (3.4%) patterns. Margins were examined for evidence of residual tumor in the 40 cases that were excised. In only one case (2.5%) was the margin positive for tumor. This was statistically significant (p less than 0.05) compared with 388 excisions of nonpigmented BCCs with comparable growth patterns in which 69 (17.7%) showed positive margins. CONCLUSION: PBCC, as a clinical variant, is more frequently excised with adequate margins than are tumors of comparable histologic subtypes that do not contain pigment.     

Basal cell carcinoma of the vulva: treatment with Mohs micrographic surgery

Vulval basal cell carcinomas (BCCs) are rare, representing < 5% of vulval malignancies and 1% of all BCCs. They often present with nonspecific symptoms and features that lead to large, poorly circumscribed and late‐presenting lesions. Current and conventional treatments used to treat vulval BCC include cryotherapy, imiquimod and excision. However, recurrence rates as high as 20% have been reported with these treatments. Furthermore, there are no current clinical guidelines for their management. We present the first reported series of patients with vulval BCC treated with Mohs micrographic surgery (MMS). We report seven cases of vulval BCC treated with MMS at a tertiary referral centre over 3 years. Follow‐up was performed at 3 months and up to 3 years. Our series demonstrates that there were no postoperative complications, functional sequelae or recurrences up to the 3‐year follow‐up. We therefore recommend that MMS should be considered in the management of vulval BCCs.     

History of Mohs surgery

Mohs micrographic surgery (MMS) has become the gold standard for treating many forms of primary and recurrent contiguous skin cancers and offers the highest cure rates and maximum tissue conservation compared with other modalities. Developed by Dr Frederic E. Mohs in the 1930s, it was initially called chemosurgery and used zinc chloride paste in a process called fixed tissue technique. Although this technique had high cure rates, it could take days to complete, and it gradually gave way to fresh tissue technique, renamed MMS. Now, MMS is practiced widely as part of a multidisciplinary approach for treating skin cancer.     

Predictors of extensive subclinical spread in nonmelanoma skin cancer treated with Mohs micrographic surgery

BACKGROUND: In nonmelanoma skin cancer, the clinically visible portion may represent a small fraction of microscopic tumor spread. Previous studies have examined individual risk factors for subclinical spread based on patient and tumor characteristics. However, these risk factors have not been prioritized or studied in combination. OBJECTIVE: To identify the most predictive risk factors for extensive subclinical tumor spread. DESIGN: Retrospective analysis of 1131 Mohs micrographic surgical cases. Variables analyzed included patient age, sex, and immune status and lesion size, location, histologic subtype, and recurrence. Logistic regression was applied to identify important combinations of tumor characteristics and to quantify relative odds of spread. SETTING: Academic referral center. PATIENTS: Consecutive sample of all referred patients treated by a single Mohs micrographic surgeon in a 3-year period. MAIN OUTCOME MEASURE: Number of Mohs micrographic surgical layers required to clear a tumor, with 3 or more layers defined as extensive subclinical spread. RESULTS: The highest-risk tumors, with odds ratios greater than 6.0, were basosquamous and morpheaform basal cell carcinoma (BCC) on the nose, morpheaform BCC on the cheek, and those with a preoperative size greater than 25 mm. Other important risk factors were recurrent and nodular BCC on the nose; location on the eyelid, temple, or ear helix; neck tumors and recurrent BCC in men; and tumor size greater than 10 mm. Patients younger than 35 years were at lower risk. Increasing age and immunocompromise were not significant predictors. CONCLUSION: Identification of lesions likely to exhibit extensive subclinical spread can help guide management to ensure complete tumor eradication and thereby reduce the risk of recurrence and its associated morbidity and cost.     

Indications and limitations of Mohs micrographic surgery

Mohs micrographic surgery is most suitable for cutaneous and mucosal neoplasms that exhibit a contiguous growth pattern and have minimal potential for metastases. Thus, a higher failure rate will be observed for tumors that exhibit multicentricity, disconnected foci, or give rise to metastases or satellite lesions. Because of its superior microscopic control, MMS offers the maximum chance for cure and preservation of normal tissue in properly selected tumors. Consequently, MMS is the treatment of choice for tumors located in cosmetically and functionally important areas of the head and neck (such as the periocular and perinasal areas), not only because of its tissue-sparing properties but also because tumors in some of these same anatomic areas also exhibit a high recurrence rate when managed by routine modalities. Variables to consider when selecting MMS to manage a neoplasm include, in addition to its anatomic location, its histology, its size, its tendency for recurrence, and whether or not it has been inadequately or previously treated. Field-fire BCC and ill-defined tumors are also best managed by MMS. When the management of a tumor exceeds the capabilities of the Mohs surgeon, an interdisciplinary approach utilizing other oncologic specialists is required (for example, reconstructive surgery, preservation of vital anatomic structures, deeply penetrating and extensive tumors, or the presence of or high risk for metastases). Because MMS is usually performed with local anesthesia on an outpatient basis, it is cost effective, safe, and extends operability to patients who are poor candidates for general anesthesia. However, when a multidisciplinary approach is employed, general anesthesia is often required. If the neoplasm is extensive, several operative sessions may be required to complete the extirpation of the tumor and the reconstruction of the defect. Although offering the greatest chance of cure for many difficult cutaneous neoplasms, MMS may at times become tedious and prolonged. Frozen sections are adequate in tracing out the microscopic extensions of most neoplasms; however, permanent sections may at times be required to provide the best microscopic control of margins, and this, too, may prolong the procedure. Histologic preparations must be of superior quality to ensure maximum microscopic control, and the surgical specimens removed must be properly oriented. On microscopic examination, benign, reactive changes and normal anatomic structures must be distinguished from tumor to avoid the unnecessary sacrifice of normal tissue, and inflammation, which may obscure tumor, must be carefully scrutinized.(ABSTRACT TRUNCATED AT 400 WORDS)