Fibromatosis in infancy and childhood: The spectrum

Fibromatosis

in Infancy and Childhood:

The Spectrum

By A. Humar, S. Chou, and B. Carpenter

Ottawa, Ontario 0 Fibromatoses form an interesting group of tumors occupying a midposition in the spectrum of fibrous tissue neoplasms. Within the fibromatoses subgroups there exists a variety of tumors whose clinical behavior spans the range from completely benign to locally aggressive. Four case histories are presented to illustrate this point. All four patients were initially seen with asymptomatic head or neck masses. The first had complete excision with no recurrence to date. The second underwent spontaneous regression after confirmation of diagnosis with biopsy. The third case had a very locally aggressive disease requiring three surgical resections to date, while the last case had one recurrence after the initial resection. With certain exceptions, initial wide local excision offers the best possible chance for cure. Copyright o 1993 by W.B. Saunders Company INDEX WORDS: Fibrous tissue neoplasms, pediatric; fibromatosis; desmoid tumors.

F

IBROMATOSES are fibrous tumors of unknown etiology, which are intermediate in their biological behaviour between benign fibrous proliferations and fibrosarcoma. Unlike the former, they may be locally aggressive, invade surrounding structures and recur after resection. However, unlike fibrosarcoma, these lesions have no tendency to metastasize. Various different entities make up the group of fibromatoses, and while their histological appearance is similar, their clinical behavior is quite varied. There is unfortunately no ideal classification system for fibromatoses at the present and a variety of terms exist for identical lesions. Different criteria such as location, histology, time of manifestation, etc, have been used and hence there is no uniformity, making comparison difficult. The classification used and presented in this article is the most recent one by Enzinger and Weiss 1*2(Table 1). The four cases presented here showcase three different types of fibromatoses and illustrate the possible spectrum of these neoplasms, ranging from spontaneous regression to local aggressiveness rivalling that of a malignancy.

From the Departments of Pediatric Surgery and Pathology, Children S Hospital of Eastern Ontario, Ottawa, Ontario. Presented at the 23rd Annual Meeting of the Canadian Association of Paediatric Surgeons, Quebec City, Quebec, September 19-22, 1991. Address reprint requests to A. Human MD, Department of Pediatric Surgery Children’s Hospital of Eastern Ontario, Universityof Ottawa, 401 Smyth Rd, Ottawa, Ontario KIH SLI, Canada. Copyright 0 1993 by W.B. Saunders Company 0022-3468i93/2811-0005$03.00/O

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CASE REPORTS

Case 1 A 4-year-old girl presented with an asymptomatic mass in the posterior neck, midline in location. Examination showed a deepseated, firm immobile and nontender mass, measuring 7 cm x 5 cm (Fig 1). Computed tomography (CT) scan showed a well-localized mass with uniform density and no suggestion of bony invasion (Fig 2). Surgical excision was carried out and pathological examination showed an extraabdominal fibromatosis (Figs 3 and 4). There has been no local recurrence at 1 year.

Case 2 A 5-week-old baby girl presented with bilateral neck masses which had been rapidly increasing in size over a l-week duration. She was born at term and was a breech with forceps delivery, but had no problems in the neonatal period. Examination showed bilateral oval shaped masses located just below the angle of the mandibles, with the right side slightly larger than the left (Fig 5). The masses were firm, mobile, and nontender. Investigations including ultrasound and CT scan were inconclusive regarding these masses and an excisional biopsy was performed on the right side. The mass was found to be adherent to the sternocleidomastoid muscle and histological examination showed an intimate admixture of proliferative fibroblasts, collagen and residual muscle fibers, consistent with fibromatosis colli (Fig 6). Follow-up over the next few months showed spontaneous regression on the left side and no recurrence on the right side, with no residual torticollis.

Case 3 A 4-year-old boy initially presented with an asymptomatic left anterior neck mass at the age of 20 months. He underwent resection on that occasion and again at the age of 26 months due to recurrence. Both times the histological diagnosis was infantile fibromatosis. He presented on this occasion with recurrence of the mass at the site of the previous resection and extending posteriorly to the region over the left scapula (Fig 7). CT scan demonstrated a large, irregular mass which was locally invasive and was extending into the extrapleural spaces (Fig 8). He underwent a two-stage procedure with anterior and posterior approaches but due to proximity to major nerves and vessels, complete resection was not possible. On histological examination, the pathologist felt that this was still most likely infantile fibromatosis, though there were certain areas suggestive of infantile fibrosarcoma with highly atypical cells (Fig 9). At this point chemotherapy was offered but the parents refused treatment after one course, due to the side effects. He has since returned with extensive disease and is presently receiving chemotherapy.

Case 4 This 4-year-old girl had initially presented with an asymptomatic posterior neck mass at the age of 3%. Excision on that occasion had demonstrated an extraabdominal fibromatosis. She returned 6 months later with a firm mass located in the area of the previous resection. Wide excision was performed and histological examination showed abundant collagen and mature fibroblasts infiltrating

JournalofPediatric Surgery, Vol28, No 11 (November), 1993: pp 1446-1450

FIBROMATOSIS

OF CHILDHOOD

Table 1. Classification of Fibromatoses

in Pediatric Population

Lesions seen in both adult and pediatric population Superficial Palmar fibromatosis (Dupuytren’s contractwe)* Plantarfibromatosis

(Ledderhose’s disease)

Deep Extraabdominal fibromatosis (extraabdominal desmoid, musculoaponeurotic fibromatosis, aggressive fibromatosis, fibromatosis NOS) Abdominal fibromatosis (abdominal desmoid) lntraabdominal fibromatosis (intraabdominal desmoid) Pelvic fibromatosis Mesenteric fibromatosis Gardner’s syndrome Lesions peculiar to infancy and childhood Fibromatosis colli Infantile fibromatosis Infantile digital fibromatosis Gingival fibromatosis Juvenile hyaline fibromatosis Fig 2. CT scan showing a well-localized into surrounding structures (case 1).

*Other terms used are given in brackets Data from Enziger and Weiss.‘,2

into the surrounding (Fig 10).

muscle, consistent

with the previous

diagnosis

DISCUSSION

Fibromatosis, although an uncommon disease in childhood, forms an important group in the spectrum of fibrous tissue tumors. The fibromatoses, as conceived by Stout,” are intermediate in their biological behavior between benign fibrous lesions and fibrosarcoma. Being “benign” lesions they never metastasize, but, like fibrosarcoma, they are capable of infiltrative growth and recurrence. Various entities make up this group, but an ideal classification system does not exist. Different criteria have been used to define the assorted lesions and as a result uniformity is lacking. Several different terms

Fig 1. With the patient on the operating table and the hair taped back, the mass is quite obvious (case 1).

mass with no infiltration

are used in the literature to describe similar entities (Table 1). The most recent classification is the one proposed by Enzinger and Weiss.‘,’ With regard to fibromatoses in children, the group can be divided into those present in both the adult and paediatric populations, and those lesions which are exclusive to infants and children. The former can be subdivided into a superficial and a deep categories. The superficial group tends to be slow-growing, small, and rarely involve deeper structures. The most common example of this is the palmar fibromatosis, which is the most common fibromatosis in the adult population, though not as common in the pediatric population. The deep group, on the other hand, tends to be faster growing and of a larger size, involving deep structures. The most common example of this is the extraabdominal fibromatosis. Abdominal fibromato-

Fig 3. Gross appearance of tumor showing prominent irregularly arranged fibrous septa, giving the “bandlike” appearance from which the term desmoid originated (case 1).

HUMAR, CHOU, AND CARPENTER

Fig 4. Sections show bands of collagen and reactive gbroblasts consistent with extraabdominal fibromatosis (case 1). (H&E, originel magnification x510.)

ses are similar histologically but arise from the musculoaponeurotic structures of the abdominal wall, and occur commonly in young women during or following pregnancy. There are several lesions that are peculiar to infancy and childhood, the two most common being infantile fibromatosis and fibromatosis colli, examples of which are presented in the previous section. Precise data regarding the epidemiology of fibromatoses in children are difficult to obtain because there are no large series dealing specifically with the pediatric population. The largest series is that of Schmidt and Harnq4 with 59 cases. They found that these lesions comprised 2.2% of all benign soft tissue tumors. Half of the patients were less than 5 years old and the male to female ratio was 1.36 to 1. The three most common lesions in their series were infantile fibromatosis (24%), extraabdominal fibromatosis (19%) and fibromatosis colli (14%). Hayashi et al5 reviewed 26 cases with a mean age of 3.3 years and the most common lesion again being infantile fibroma-

Fig 5. Bilateral neck masses in a !&week-old patient, easily visible with the right side being slightly larger (case 2).

Fig 6. Sections of sternocleidomastoid muscle show fibrosis admixed with residual muscle consistent with fibromatosis colli (case 2). (H&E, original magnification x440.)

tosis. All four of the present patients were below the age of 5 at the initial presentation. Commonly these tumors result in an asymptomatic mass which is firm, solid, and nontender on examination. Symptoms may occur, however, if the growth of these entities impinges upon important structures such as nerves, vessels, or the airway. Intraabdominal lesions may derange normal function by expanding

Fig 7. Large mass extending from the neck anteriorly to overly the scapular region posteriorly. The large scar marks the previous resections (case 3).

Fig 8. CT scan showing large mass occupying the space between the sternomastoid and paraspinal muscles and extending inferiorly and posteriorly. Note the extrapleural extension between the intercostal spaces (case 3).

within the abdomen. The different fibromatoses have a predilection to arise from certain anatomic sites. Fibromatosis colli by definition is always located in the neck, just as fibromatosis palmaris/plantaris always arise in the extremities. Infantile fibromatosis is most commonly located in the musculature of the head, neck, shoulder, upper arm, or thigh,’ while extraabdominal fibromatosis is more often found in the chest wall, back, and thigh. The clinical behavior and course of these lesions can be quite varied and show a wide spectrum. This is well illustrated by the cases presented here. At one end of the spectrum is a lesion like fibromatosis colli. This peculiar growth of the sternocleidomastoid muscle characteristically appears during the first weeks of life and may be unilateral or bilateral. It may or may not be associated with torticollis. There is

Fig 9. Sections showed features of infantile fibromatosis (left, H&E, original magnification x510) and infantile fibrosarcoma (right, H&E, original magnification x320), the spectrum seen with infantile fibromatosis, presented in different areas of the same specimen. Top left shows mature fibroblasts and abundant collagen. Other areas show increased cellularity with decreased collagen and increased immature fibroblasts. Bottom right shows atypical cells and mitotic figures almost suggestive of fibrosarcoma (case 3).

Fig 10. Sections show bands of collagen and reactive fibroblasts consistent with extraabdominal fibromatosis (case 4). (H&E, original magnification x440.)

initial rapid growth which then slows and eventually complete regressions occurs, without tendency for either aggressive behaviour or recurrence. This was the pattern followed by case 2. Histologically this lesion appears very similar to extraabdominal fibromatosis, but clinically it behaves quite differently. Extraabdominal fibromatosis will not usually regress spontaneously and tends to show infiltration into surrounding soft tissues. There is the potential to attain large sizes and a 25% to 60% chance of recurrence after excision. Of the two cases presented here, one showed local recurrence and infiltrative growth (case 4) while the other (case 1) was quite well localized and to date has not recurred. Histologically the two cases appear quite similar, although case 1 was more cellular and did not have as abundant collagen as compared with case 4, which incidentally was clinically more aggressive. Infantile fibromatosis, often regarded as the childhood counterpart of extraabdominal fibromatosis, tends to be the most aggressive member of this group. There is considerable variation in the tumor ranging from primitive mesenchymal forms to lesions resembling adult fibromatosis. The cellular variants of this group can show a high content of atypical cells with increased mitotic activity and can be very difficult to differentiate from infantile fibrosarcoma. The recurrence rate is quite high (60%) and these lesions can be very aggressive locally as depicted by case 3. With some exceptions, early wide excision with adequate margins probably provides the best chance for a cure. This would not apply for fibromatosis colli which tends to regress spontaneously, but is appropriate for many other types of fibromatoses. Treatment for those with repeated recurrence or those in whom adequate excision would be impossible or too mutilat-

HUMAR, CHOU, AND CARPENTER

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ing, remains uncertain. There have been reports of chemotherapy and radiotherapy usage with good response. 6’ Raney et al7 reported three patients treated with VAC (Vincristine, Actinomycin D, Cyclophosphamide). Two had complete disappearance and one had 50% regression. However, chemotherapy is not without side effects, and our own patient (case 3) refused further treatment after one course. Radiotherapy has also been used, but again it is not with problems, especially in the pediatric population. In the report by Raney et al,’ amongst three patients who had received radiotherapy and chemotherapy, one went on to develop papillary carcinoma of the thyroid. Thus, it is hard to justify an aggressive

therapy for what are essentially considered benign lesions. In summary, several important points can be made about this group of tumors. While uncommon, they should be considered among the differential diagnosis of soft tissue masses. A wide clinical spectrum can be seen from the various entities that make up this group, ranging from spontaneous regression to aggressive local invasion. The exact behavior of these lesions can be difficult to predict at times. With certain exceptions, however, early wide excision usually is the best option despite the fact that these are “benign” tumors. For recurrent or unresectable disease, chemotherapy or radiotherapy may be an option.

REFERENCES 1. Enziger FM, Weiss SW: Fibromatoses, in Soft Tissue Tumors. St Louis, MO, Mosbv, 1983, pp 45-70 2. Enziger FM, Weiss SW: Fibrous proliferation in infancy and childhood, in Soft Tissue Tumors. St Louis, MO, Mosby, 1983, pp 71-102 3. Stout AP: Juvenile fibromatosis. Cancer 7:953-978,1954 4. Schmidt D, Harms D: Fibromatosis of infancy and childhood-

Histology and ultrastructure and clinicopathologic correlation. Kinderchir 40:40-46.1985 5. Hayashi Y, Spitz L, Kiely E, et al: Fibrous tissue tumors. Prog Pediatr Surg 22:121-132,1989 6. Kiel Kd, Suit HD: Radiation therapy in the treatment of aggressive fibromatoses. Cancer 54:2051-2055,1984 7. Raney B, Evans A, et al: Nonsurgical management of children with recurrent or unresectable fibromatosis. Pediatrics 79:394-398. 1987