Desmoplastic Fibroblastoma of the Supraclavicular Region: A Rare Soft-Tissue Tumor With a Review from the Last Decade

Introduction

Desmoplastic fibroblastoma (DF), or collagenous fibroma, is a rare, fibrous soft-tissue tumor that typically arises in the subcutaneous tissue of the upper extremities. According to the WHO 2020 classification, DF belongs to the fibroblastic/myofibroblastic tumor group. ¹

Desmoplastic fibroblastoma has a benign course, and its etiology remains unknown; however, preceding trauma may be a contributing factor. ² Morphologically, DF resembles soft-tissue desmoid tumors, commonly seen in the abdominal wall.^3,4 It is more common in men, with a peak incidence in the fifth through seventh decades of life. ⁵ DF generally manifests as a firm, slow-growing, and painless subcutaneous mass with a broad anatomic distribution. ⁶ Its incidence in the head and neck area, however, is uncommon, with DF in the supraclavicular region being the rarest and most challenging to treat. ⁴ This is primarily owing to the surrounding vital structures being confided in a relatively small space. Complete surgical excision is the recommended treatment.

Here, we report the first case of supraclavicular DF from Saudi Arabia, aiming to contribute to the data pool of this rare tumor by emphasizing its presentation, diagnosis, treatment, and outcome. As a result, this case report will aid in facilitating future guidelines for diagnostic and treatment approaches. We also reviewed pertinent literature concerning this rare tumor, focusing on those tumors that occur in the supraclavicular region and cephalad.

Case Report

A 45-year-old man with no significant medical or family history was referred to our center with a 6-month history of a neglected right neck mass. Initially, the patient was asymptomatic; with time, the mass started to cause bothersome numbness in the right arm, for which he sought physical therapy. The physiotherapist incidentally noticed the mass and instructed the patient to seek medical attention. Further questioning revealed no history of trauma or any other sensory deficit. Physical examination of the neck showed a supraclavicular mass that is firm, immobile, and non-tender to palpation. It measured around 4 × 3 cm. Apart from the patient’s complaint, the neurological examination was intact.

Computed tomography (CT) with contrast showed a well-defined, 5.4 × 3.5 × 5.4-cm mass in the right supraclavicular region. The mass was isodense to the surrounding muscles with poor heterogeneous enhancement. It was compressing the surrounding vessels and nerves without any signs of invasion (Figure 1A‐1B). On contrast magnetic resonance imaging (MRI), the mass was isointense to hypointense to the surrounding muscles on both T1 and T2 imaging with minimal enhancement (Figure 2A–2D). The decision of core needle biopsy was made, and histopathology revealed spindle-cell fibroblastic proliferation on a myxoid/collagenized background with no evidence of significant mitotic activity or tumor necrosis compatible with DF (Figure 3).OPEN IN VIEWER

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Figure 2.

Magnetic resonance imaging of the neck (A; T1, axial view, B; T1, coronal view, C; T2 coronal view, D; T1 coronal view with contrast) showing a supraclavicular mass (arrows) isointense to surrounding muscles on T1, with heterogeneous enhancement on the contrasted image.

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Figure 3.

Low power (A), intermediate power (B), and high power (C) magnification depicting stellate and spindle neoplastic cells with prominent collagen in the background with bland spindle fibroblastic cells with no significant nuclear pleomorphism, mitotic activity, and necrosis.

Subsequently, surgical excision of the mass under general anesthesia was recommended. The tumor was excised using a transcervical approach after dissecting it off from the clavicle and surrounding major vessels and nerves. Finally, the drain was placed along the incision line, and closure was done in two layers. The patient was sent for recovery without complications, and the drain was removed on postoperative day 1, with marked improvement in his neurological symptoms. The patient was discharged with no complaints. During 2 years of regular follow-up, numbness disappeared without signs of recurrent or residual disease.

Discussion

DF is an uncommon benign soft-tissue tumor first introduced by Evans. ⁷ Nielsen et al. ⁸ renamed it as “collagenous fibroma” for a better description of its histological features and reflection of its favorable prognosis. DF may develop without any history of trauma or inciting event, ⁹ as was the case of our patient. This, in part, lends credence to the hypothesis that this tumor is indeed the result of a neoplastic process. ⁹

DF mostly affect adult men with manifestations depending on the tumor size and location. ¹⁰ It may be asymptomatic or have nonspecific symptoms ¹¹ like local pain and tingling, as was the case of our patient.

Diagnosing DF often requires multiple diagnostic modalities such as radiology (both CT and MRI) and biopsy with histopathology. Radiological investigations allow characterization of the mass and provide information about its location, dimensions, and adjacent vital structures and help rule out invasion. Radiology also helps during treatment planning. MRI is superior to CT with regard to characterization and extent definition of DF, with MRI revealing a well-defined mass surrounded by condensed connective tissue and a notable low-signal intensity on all pulse sequences.^6,12 To suspect DF on radiological investigations, one must become familiar with its key imaging features. Nakayama et al. ⁶ suggested that the enhancement pattern on contrast-enhanced MRI and the presence of a low-signal-intensity band may be employed as distinguishable features similar to those found in our case (Figure 2D). The radiological findings of DF are nonspecific and may yield only a presumptive diagnosis. Radiological differential diagnoses of DF include desmoid tumor, neurofibroma, fibromatosis, and elastofibroma. Histopathological examination of tissue obtained through incisional biopsy is a valuable method to differentiate DF from other soft-tissue tumors, mainly desmoid-type fibromatosis (which requires more intensive treatment).^2,6 DF presents histologically as a hypocellular lesion consisting of spindle to stellate-shaped cells embedded in a dense collagenous or myxocollagenous stroma. ⁶ Nevertheless, with this many differentials at hand, a diagnostic dilemma might arise. Therefore, the addition of immunohistochemistry and cytogenetics to the workup can mitigate the similarity between DF and other mimics. FOSL1 immunostaining and a t(2;11)(q31;q12) translocation are both features that have been shown to be helpful in the diagnosis of DF. ⁶

To our knowledge, this present case is the first from the Gulf region and Saudi Arabia. To further expand our understanding, we performed a literature review of all documented cases of DF occurring in the head and neck region and cephalad over the last 10 years. Through the usage of relevant search terms in both the title and abstract: “desmoplastic fibroblastoma” and “collagenous fibroma,” we retrieved publications in PubMed. Our search yielded 18 published cases in PubMed written in English, of which 10 were included in this study. DF cases occurring outside the supraclavicular region and cephalad were excluded. Data on presenting symptoms of DF, location, radiological findings, treatment, complication, recurrence, and follow-up were collected for all cases. Of these cases, the majority included women (n = 6) aged 8‐82 years. The predominant presenting symptoms were painless swelling, consistent with the symptom of our case. The tumor sizes ranged from 0.4 × 0.2 × 0.4 cm to 18 × 14 × 17.5 cm. Almost all cases required complete surgical excision, and only one had postoperative complications. No recurrence events were reported during the mean follow-up period of 7.7 months (Table 1).

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Table 1.

Review of All Reported Cases of Desmoplastic Fibroblastoma in the Supraclavicular Region and Cephalad Have Been Published in English Between 2012 and 2022.

Case no.	Author	Year of Publication	Sex	Age (years)	Location	Size	Presenting Symptoms	Initial Treatment	Surgical Complications	Recurrence	Mean Follow-Up Duration
1.	Bhagalia et al. 14	2012	F	58	Oral cavity (lingual gingival region)	2 × 1 cm	Firm, slow-growing mass	Completely excised under local anesthesia	None reported	None reported	N/A
2.	Nagaraja et al. 15	2013	M	47	Right parotid gland	11 × 12 × 9 mm	Painless swelling	Surgical excision was performed under general anesthesia	None reported	No	6 months
3.	Stacy, et al. 16	2013	F	40	Orbital rim	1 × 1 × 1 cm	Painful swelling	Small portion of the orbital wall was removed, followed by reconstruction with a titanium mesh, excised along with a portion of the bony orbital rim	None reported	None reported	N/A
4.	Dadlani et al. 17	2014	F	20	Calvarium	18 × 14 × 17.5 cm	Progressive swelling on the anterior scalp noticed at the age of 5 years	Surgical excision of lesion along with reconstructive surgery	Acute breathlessness and collapsed on postoperative day 9, preceded by a 4-day history of lower limb swelling, which the patient ignored	None reported	Certified dead on-arrival at a local hospital with a diagnosis of pulmonary embolism secondary to deep venous thrombosis
5.	Varghese et al. 18	2014	M	8	Oral cavity (left buccal mucosa)	3 × 2 cm	Painless swelling	Surgical excision	None reported	No	1 year
6.	Pereira et al. 9	2015	M	56	Oral cavity (left mandibular alveolar ridge)	N/A	Painless swelling	Surgical excision	None reported	No	8 months
7.	Jaafari-Ashkavandi et al. 19	2015	F	58	Oral cavity (anterior part of maxilla)	1.3 × 1 × 1 cm	Asymptomatic	Excisional biopsy	None reported	No	1 year
8.	Tokura et al. 20	2018	F	66	Oral cavity (tongue)	13 × 12 mm	Painless swelling	Surgical excision was performed under general anesthetic	None reported	No	1 year
9.	Vasconcelos et al. 21	2018	F	48	Oral cavity (hard palate)	A- 4.5 × 1.8 × 0.8 cm B- 2.3 × 2.0 × 1.5 cm	Painless bilateral swelling	Surgical excision	None reported	No	2 years
10.	Yang et al. 22	2018	M	82	The scalp	0.4 × 0.2 × 0.4 cm	Tiny painful, tender mass	Surgical excision	None reported	No	3 months

Radiographic imaging was used in almost all cases to identify and examine the nature of the tumor (Table 2).

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Table 2.

Radiological Findings of Reported Cases of Desmoplastic Fibroblastoma in the Supraclavicular Region and Cephalad.

Author	Modality	Findings
Bhagalia et al. 10	Intraoral radiography	N/A
Nagaraja et al. 11	US	A well-defined 11 × 12 × 9-mm mass identified at the lower pole of the right parotid gland.
Stacy et al. 12	CT	A 1-cm mass at the frontozygomatic junction at the orbital rim with slight bony erosion and spiculation.
Dadlani et al. 13	CT/MRI	CT: Spiculations arising from the outer table, further delineated on three-dimensional reconstruction. MRI: Giant heterogeneous lesion measuring 18 × 14 × 17.5 cm and involving both frontal bones and bilateral superior orbital ridges, markedly hypointense on both T1- and T2-weighted sequences, with a soft-tissue component that was isointense on T1-weighted and heterointense on T2-weighted images. Multiple hypointense bony “sun ray” spicules noted to be extending into the soft-tissue component.
Varghese et al. 14	Intraoral radiography	Root stump in 85 and deep caries in 84. Root resorption involving 84 and 85 along with erupting 44 and 45. No evidence of any periapical or other osteolytic lesions.
Pereira et al. 7	Panoramic radiography	Irregular alveolar bone loss from area underlying the tumor until the 34th tooth.
JAAFARI-ASHKAVANDI et al. 15	Periapical radiograph	A well-defined radiolucent lesion mimicking periapical lesions.
Tokura et al. 16	US/MRI	US: A well-circumscribed mass, which was 9 mm deep and 8 mm wide, on the left dorsal surface of the tongue. The mass was heteroechoic and lacked blood flow. MRI: Low signals within the tumor on T2-weighted images and signals in the surrounding intact musculature on T1-weighted images.
Vasconcelos et al. 17	Not mentioned	N/A
Yang et al. 18	US	A 0.4 × 0.2 × 0.4 cm hypoechoic nodule on aponeurosis with no compressibility and no vascularity.

Total surgical excision remains the definitive and recommended treatment approach, with an excellent prognosis and no reports of local recurrence. ¹⁹ These findings highlight the importance of health education in the community to raise awareness about painless masses to facilitate early detection, thereby avoiding possible impediments in providing optimal treatment. Since this tumor’s main manifestation is painless swelling that may be left untended until the emergence of symptoms. It also highlights that a rare disease like DF, with many possible differentials, needs other confirmatory tests, so they are not missed.

Conclusion

DF is a rare, indolent, benign soft-tissue tumor. The diagnosis of DF requires a high level of suspicion owing to its rarity and lack of specificity of clinical and radiological findings. The presented case further braces the clinical and surgical evaluation of DF. Histopathological examination is indispensable for an accurate diagnosis. The definitive treatment is total surgical excision with an excellent prognosis and no reported instances of recurrence. Long-term postoperative monitoring would be prudent while avoiding extensive surgical treatment or radiotherapy.