Benign Surprise: A Case in Oncology Cases Elastofibroma

Patient Presentation & History

A 72-year-old male, retired construction worker, presented with a 2-year history of a slowly enlarging, deep-seated mass in the left posterior thoracic region, inferior to the scapula. The patient reported a dull ache and a persistent sensation of pressure, particularly when lying supine or during overhead activities. He also described an intermittent "snapping" or "grinding" sensation with scapular movement, which had become more pronounced over the last 6 months. There was no history of acute trauma to the area; however, the patient recalled a minor, non-impact fall approximately 3 years prior where he landed on his back, experiencing transient muscle soreness that resolved spontaneously. He had initially attributed his symptoms to age-related musculoskeletal changes or a persistent muscle strain.

His past medical history was significant for well-controlled hypertension and hyperlipidemia. He was a former smoker (quit 20 years prior) and consumed alcohol occasionally. There was no personal or family history of malignancy. He had no constitutional symptoms such as fever, night sweats, or unintentional weight loss. He denied any neurological deficits or paresthesias in the ipsilateral upper extremity. The progressive nature of the mass and the onset of mechanical symptoms prompted him to seek medical evaluation. His primary care physician, concerned about the differential diagnosis of a deep soft tissue mass in an elderly patient, referred him to Orthopedic Oncology.

Clinical Examination

Inspection

On visual inspection, a subtle fullness was noted in the left infrascapular region. There was no overlying skin erythema, discoloration, ulceration, or obvious skin changes. No prominent venous patterns were observed. The scapula appeared to be in a normal resting position, and there was no obvious winging or asymmetry at rest. Symmetry of the shoulder girdles and overall posture were unremarkable.

Palpation

Palpation revealed a firm, ill-defined, non-tender, deep-seated mass measuring approximately 8 x 6 cm in the left infrascapular region, deep to the latissimus dorsi and rhomboid musculature. The mass felt somewhat rubbery with a distinct fibrous consistency. It was relatively mobile relative to the overlying skin and superficial fascia but exhibited restricted mobility relative to the chest wall and underlying deeper structures . There was no warmth or crepitus on palpation. Deep palpation elicited the patient's described pressure sensation but no sharp pain. A "clunking" sensation was appreciated with passive and active scapular protraction and retraction, suggesting impingement or friction between the mass and the scapula/rib cage.

Range of Motion

• Cervical Spine: Full active and passive range of motion, non-painful.
• Left Shoulder:
  • Active Range of Motion: Forward flexion 160°, abduction 150°, external rotation 60° (with arm at side), internal rotation to T8. End-range movements, particularly abduction and forward flexion, were limited by a deep pressure sensation, not acute pain. The snapping sensation was reproducible during active scapulothoracic motion.
  • Passive Range of Motion: Symmetric with active range, indicating no significant capsular restriction or adhesive capsulitis.
• Right Shoulder: Full and painless active and passive range of motion.

Neurological & Vascular Assessment

• Left Upper Extremity Neurological: Intact motor function (MRC grade 5/5) in all myotomes (C5-T1). Intact sensation to light touch and pinprick in all dermatomes. Deep tendon reflexes (biceps, triceps, brachioradialis) were 2+ and symmetric bilaterally. No pathological reflexes were elicited.
• Left Upper Extremity Vascular: Strong and symmetric radial and ulnar pulses. Capillary refill was brisk (<2 seconds). No evidence of edema or trophic changes. Axillary lymph nodes were non-palpable.

Imaging & Diagnostics

Initial Radiographs (Left Shoulder and Thorax)

Anterior-posterior (AP) and lateral views of the left shoulder, along with AP and lateral views of the chest, were performed.
* Findings: Radiographs demonstrated no evidence of osseous destruction, periosteal reaction, or calcification associated with the palpable mass. The bony architecture of the scapula, humerus, clavicle, and thoracic cage appeared unremarkable for age. No overt soft tissue mass was clearly delineated, indicating the lesion was likely isodense to surrounding soft tissues and not calcified or ossified. The lung fields were clear, and the cardiomediastinal silhouette was within normal limits.

Ultrasound

An initial ultrasound was performed to characterize the mass further.
* Findings: Ultrasound revealed a hyperechoic, heterogeneous, poorly circumscribed lesion deep to the latissimus dorsi muscle, appearing to infiltrate or displace adjacent muscle fibers. It measured approximately 7.5 x 5.8 x 4.2 cm. Color Doppler showed minimal internal vascularity. The sonographer's report suggested a soft tissue mass, possibly benign (e.g., lipoma or fibroma) but recommended MRI for definitive characterization due to its deep location and ill-defined margins.

Magnetic Resonance Imaging (MRI)

MRI of the left shoulder and chest wall was ordered with and without intravenous gadolinium contrast for comprehensive evaluation.
* Findings:
* Location: A large, lenticular-shaped, ill-defined soft tissue mass was identified in the infrascapular region, located between the serratus anterior and the chest wall (specifically, the rhomboid major and latissimus dorsi, or deep to the serratus anterior and superficial to the rib cage).
* Signal Characteristics:
* T1-weighted sequences: The mass demonstrated heterogeneous signal intensity, predominantly iso- to slightly hyperintense relative to skeletal muscle, with characteristic interspersing areas of signal intensity similar to subcutaneous fat. This "striated" or "checkerboard" appearance was highly suggestive.
* T2-weighted sequences with fat saturation: The lesion showed heterogeneous high signal intensity, with the interspersed fatty components suppressed. There was no significant perilesional edema.
* STIR sequences: High signal intensity, confirming fluid/non-fatty components.
* Post-contrast T1-weighted sequences with fat saturation: The mass exhibited mild, diffuse, heterogeneous enhancement, primarily involving the fibrous components, while the fatty streaks remained unenhanced.
* Dimensions: Approximately 8.0 x 6.5 x 4.5 cm.
* Relationship to adjacent structures: The mass appeared to be intimately associated with the fascial planes of the serratus anterior and rhomboid major muscles, possibly originating from the subscapular connective tissue. It caused mild displacement of the scapula anteriorly but no direct invasion of the adjacent musculature or rib cage was evident.
* Other findings: No regional lymphadenopathy. No signs of pathological fracture or bone erosion.
* Impression: The MRI features, particularly the characteristic heterogeneous signal intensity with intermingled fibrous and fatty components, were highly suggestive of an elastofibroma dorsi. However, given the patient's age and the size of the mass, a low-grade sarcoma (e.g., atypical lipomatous tumor/well-differentiated liposarcoma) could not be definitively excluded based on imaging alone, necessitating histological confirmation.

Biopsy

Due to the persistent symptoms and the imaging characteristics, which, while highly suggestive of elastofibroma, did not entirely rule out malignancy, an ultrasound-guided core needle biopsy was performed.
* Technique: Under local anesthesia, multiple core samples were obtained from different areas of the mass.
* Histopathology: Microscopic examination of the biopsy specimens revealed haphazardly arranged bundles of thick, eosinophilic collagen fibers mixed with fragmented, coarse, and deeply basophilic elastic fibers. Adipose tissue was intermingled throughout. There was no cellular atypia, pleomorphism, or mitotic activity. The pathological diagnosis was consistent with Elastofibroma Dorsi .

Differential Diagnosis

The differential diagnosis for a deep-seated soft tissue mass in the infrascapular region in an elderly patient is broad, encompassing both benign and malignant entities. Prior to the definitive biopsy, the primary considerations were as follows:

Surgical Decision Making & Classification

The definitive diagnosis of Elastofibroma Dorsi by core needle biopsy was a "benign surprise" given the initial clinical suspicion and imaging characteristics that could not entirely exclude a low-grade malignancy like an Atypical Lipomatous Tumor. While elastofibroma is definitively benign with no malignant potential, surgical intervention was decided upon for the following reasons:

1. Symptomatic Relief: The patient experienced significant mechanical symptoms, including a persistent dull ache, pressure sensation, and reproducible snapping/clunking of the scapula with movement, impacting his daily activities and sleep. This was the primary indication for excision.
2. Diagnostic Certainty (despite biopsy): Although the biopsy indicated elastofibroma, the possibility of sampling error in a large, heterogeneous mass (missing a potentially malignant focus) remained a minor concern. Complete excision provides the ultimate histological confirmation and reassurance.
3. Prevent Future Complications: Although rare, very large elastofibromas can cause nerve compression or chronic pain due to persistent friction. Excision prevents further growth and potential worsening of symptoms.

Classification:

Elastofibroma dorsi is not typically subject to trauma-related classifications (e.g., AO/OTA for fractures). For soft tissue tumors, the most relevant classification system is often the Enneking Staging System for Musculoskeletal Tumors , which broadly categorizes tumors based on grade, site, and metastatic status.
* Grade: Elastofibroma is a benign lesion, therefore categorized as G0 (Benign) .
* Site: The mass was extra-compartmental (T1) or possibly intra-compartmental (T0) depending on the definition of its deep fascial origin. Given its infiltrative pattern between muscle layers, it is often considered T1 (Extracompartmental) in the context of soft tissue tumors, meaning it extends beyond the boundary of the major fascial compartments.
* Metastasis: No evidence of regional or distant metastases (M0).

Therefore, according to the Enneking system, this lesion would be classified as a Stage 0 (Benign) tumor . The goal of surgery for benign symptomatic lesions is typically marginal or wide local excision, aiming for complete removal of the lesion.

Surgical Technique / Intervention

The procedure was performed under general anesthesia with the patient in a prone position to optimize exposure of the posterior thoracic wall and scapular region.

Patient Positioning and Preparation

1. Positioning: Patient was carefully positioned prone on a Jackson table or a similar radiolucent operating table, ensuring adequate padding at pressure points. The left arm was prepped free to allow for intraoperative manipulation of the scapula, which aids in exposing the deep infrascapular space. A bolster was placed under the ipsilateral chest to slightly elevate the operative field and stretch the shoulder girdle.
2. Prepping and Draping: The entire left posterior shoulder, scapular region, and chest wall, extending to the axilla and mid-back, were prepped with an antiseptic solution (e.g., chlorhexidine-alcohol) and draped in a sterile fashion, ensuring wide exposure and access for potential extension of the incision if required.

Incision and Approach

1. Incision: A curvilinear incision approximately 12 cm in length was marked over the palpable mass, running parallel to the medial border of the scapula, slightly lateral to the midline. This provides excellent exposure while minimizing tension on the skin edges.
2. Skin and Subcutaneous Dissection: The incision was carried through the skin and subcutaneous tissue. Subdermal flaps were raised minimally to allow for visualization and mobilization.
3. Muscle Layers: The deep fascia overlying the latissimus dorsi was incised. The latissimus dorsi muscle fibers were identified and carefully retracted laterally. The underlying rhomboid major muscle was then identified. Given the deep location of the mass, often lying between the rhomboids and serratus anterior, or deep to the serratus anterior, careful dissection was paramount. In this case, the mass was found to be situated predominantly deep to the rhomboid major and minor muscles. These muscles were carefully split along their fibers or retracted medially and laterally to expose the tumor capsule. The serratus anterior was identified anterior to the mass.

Tumor Resection

1. Identification of Mass: The elastofibroma was identified as a large, firm, grayish-white to yellowish-tan, poorly encapsulated mass with a characteristic irregular, fibrillar, and somewhat fatty appearance. It was intimately adherent to the deep fascial planes.
2. Dissection and Mobilization: Using a combination of sharp and blunt dissection, the mass was meticulously dissected free from the surrounding musculature and fascial attachments. Electrocautery was used cautiously for hemostasis. The goal was to achieve a complete marginal excision. Special attention was paid to identifying and preserving neurovascular structures in the area, including the dorsal scapular nerve and artery (supplying rhomboids and levator scapulae), and the long thoracic nerve (supplying serratus anterior), which lie deep and can be at risk.
3. En Bloc Excision: The tumor was excised en bloc with a thin rim of surrounding normal-appearing soft tissue to ensure clear margins, consistent with a marginal excision for a benign lesion. The final dimensions of the excised specimen were 8.2 x 6.7 x 4.6 cm.
4. Hemostasis: Thorough hemostasis was achieved using bipolar cautery. The wound was copiously irrigated with sterile saline.

Closure

1. Drain Placement: A closed suction drain (e.g., 10F Blake drain) was placed in the deep cavity to prevent seroma formation, which is a common complication in such a large dead space.
2. Muscle Repair: The split muscle layers (rhomboids, latissimus dorsi) were reapproximated with absorbable sutures (e.g., 2-0 Vicryl) to restore anatomical integrity and minimize dead space.
3. Fascial Closure: The deep fascia was closed with interrupted absorbable sutures.
4. Subcutaneous Closure: The subcutaneous layer was closed with interrupted absorbable sutures (e.g., 3-0 Vicryl).
5. Skin Closure: The skin was closed with either staples or an interrupted non-absorbable suture (e.g., 3-0 nylon) or a running subcuticular suture, depending on surgeon preference. A sterile dressing was applied.

Post-Operative Protocol & Rehabilitation

The post-operative protocol focused on pain management, wound care, and gradual restoration of upper extremity function, with an emphasis on preventing stiffness and muscle atrophy while allowing for soft tissue healing.

Immediate Post-Operative (Day 0-7)

• Pain Management: Multimodal analgesia including intravenous (PCA) or oral opioids, NSAIDs (if no contraindications), and acetaminophen. Nerve blocks (e.g., interscalene) were considered pre-operatively but often not necessary for this location.
• Wound Care: Daily dressing changes. Monitoring for signs of infection, hematoma, or seroma.
• Drain Management: The closed suction drain was monitored for output and removed when output was consistently less than 20-30 mL over 24 hours (typically POD 2-4).
• Mobility: Gentle active-assisted and passive range of motion of the ipsilateral shoulder and elbow, within a pain-free arc. Avoidance of aggressive abduction, overhead flexion, and external rotation to protect the surgical site. A shoulder sling was used for comfort and to limit uncontrolled movements, but not for immobilization.
• Respiratory Care: Incentive spirometry and deep breathing exercises to prevent atelectasis, especially with a posterior thoracic incision.
• Discharge: Patients typically discharged POD 1-3 once pain is controlled and drain output is minimal.

Early Rehabilitation (Weeks 1-6)

• Phase I: Protection and Early Motion (Weeks 1-3)
  • Goal: Protect surgical repair, reduce pain/swelling, restore passive range of motion.
  • Activities: Continue pain control. Gentle pendulum exercises. Passive range of motion (PROM) for shoulder flexion, abduction (to 90°), and internal/external rotation (neutral to 45°). Gentle scapular mobilization exercises. Isometrics for shoulder musculature (rotator cuff, deltoid) as tolerated, avoiding strong contractions of rhomboids/latissimus.
  • Restrictions: No heavy lifting (>5 lbs). Avoid active resistive exercises for rhomboids/latissimus. Avoid sleeping on the operative side.
• Phase II: Progressive Active Motion & Strengthening (Weeks 3-6)
  • Goal: Restore active range of motion (AROM), initiate gentle strengthening.
  • Activities: Progress to active-assisted range of motion (AAROM) and then AROM. Initiate light resistance exercises for rotator cuff and deltoid with resistance bands. Begin gentle scapular stabilization exercises. Soft tissue mobilization and scar management as needed.
  • Restrictions: Continue to avoid heavy lifting. Gradually increase range of motion and strength.

Intermediate Rehabilitation (Weeks 7-12)

• Phase III: Advanced Strengthening & Functional Progression (Weeks 7-12)
  • Goal: Achieve full range of motion, progress strengthening, return to most activities of daily living.
  • Activities: Progress strengthening exercises with increasing resistance (weights, bands). Focus on functional movements and restoring endurance. Incorporate exercises for latissimus dorsi and rhomboids with light resistance. Proprioception and neuromuscular control exercises.
  • Return to Activity: Gradual return to light occupational tasks. Recreational activities (e.g., swimming, golf) with modified technique, as tolerated.

Advanced Rehabilitation (>12 Weeks)

• Phase IV: Return to Full Activity
  • Goal: Optimize strength and endurance, return to pre-morbid activity levels.
  • Activities: Continue advanced strengthening. Sport-specific or work-specific rehabilitation as needed.
  • Return to Work: Full return to work, including physically demanding activities like construction, typically by 3-6 months, depending on individual progress and the physical requirements of the job.

Close communication between the surgeon, physical therapist, and patient is essential throughout the rehabilitation process to individualize the plan and address any setbacks.

Pearls & Pitfalls (Crucial for FRCS/Board Exams)

Pearls

1. Clinical Presentation: Elastofibroma dorsi often presents in elderly patients (>50 years) with a slowly growing, deep-seated, firm, rubbery mass in the infrascapular region (most commonly between the serratus anterior and the chest wall, deep to the rhomboids/latissimus dorsi). It can cause mechanical symptoms like snapping scapula, dull ache, or pressure.
2. Location: The classic location is the infrascapular region, but it can occur elsewhere (e.g., axilla, chest wall, extremities), though less common. Bilateral occurrence is reported in 10-60% of cases, making it crucial to inspect the contralateral side and potentially image it.
3. MRI is Key: MRI is the imaging modality of choice. The characteristic MRI findings of elastofibroma dorsi are usually pathognomonic: a heterogeneous, ill-defined mass with intermingled streaks of fat (hyperintense on T1, suppressed on fat-sat) and fibrous tissue (iso/hypointense on T1, hyperintense on T2). Mild, diffuse enhancement is typical. Recognition of these features can often obviate the need for biopsy if the patient is asymptomatic.
4. Histology: Definitive diagnosis is histological, revealing haphazardly arranged bundles of thick, eosinophilic collagen fibers mixed with fragmented, coarse, and deeply basophilic elastic fibers, intermingspersed with mature adipose tissue. There is a complete absence of cellular atypia or mitotic activity.
5. Benign Nature: Elastofibroma is a benign, reactive fibrous lesion, not a true neoplasm. It has no malignant potential and does not metastasize.
6. Indications for Surgery: Excision is indicated for symptomatic lesions (pain, mechanical irritation, snapping scapula) or for definitive diagnosis when imaging and biopsy are equivocal and malignancy cannot be excluded. Asymptomatic lesions with classic MRI features can be observed.
7. Surgical Approach: A prone position and a curvilinear incision parallel to the medial border of the scapula provide excellent access. Careful dissection through the latissimus dorsi and rhomboid muscles is required.
8. Neurovascular Protection: Awareness of the dorsal scapular nerve and long thoracic nerve is crucial during dissection in the scapular region.

Pitfalls

1. Misdiagnosis as Malignancy: The primary pitfall is misinterpreting an elastofibroma as a sarcoma (e.g., liposarcoma, desmoid tumor) due to its size, deep location, and sometimes ill-defined margins, especially if MRI findings are not classic or if the interpreting radiologist is unfamiliar with the lesion. This can lead to unnecessary extensive workup or inappropriate surgical planning.
2. Sampling Error on Biopsy: While core needle biopsy is typically diagnostic, heterogeneous lesions carry a small risk of sampling error. If clinical suspicion of malignancy remains high despite a benign biopsy (e.g., very rapid growth, highly atypical imaging, or concerning patient factors), a repeat biopsy or excisional biopsy may be considered, though this is rare for classic elastofibroma.
3. Inadequate Excision / Local Recurrence: Although not a "recurrence" in the sense of a neoplastic growth, incomplete excision of elastofibroma can lead to persistent symptoms. Meticulous dissection and marginal excision are important, but complete excision can be challenging due to the infiltrative nature into surrounding fascial planes.
4. Seroma Formation: The creation of a large dead space after removal of a substantial deep-seated mass can predispose to seroma formation. Careful layered closure and placement of a closed suction drain are essential preventative measures.
5. Iatrogenic Nerve Injury: The long thoracic nerve, dorsal scapular nerve, and thoracodorsal nerve are all vulnerable during extensive dissection in the infrascapular and axillary regions. Meticulous surgical technique with precise anatomical knowledge is required.
6. Over-Immobilization: Post-operative over-immobilization of the shoulder can lead to stiffness or adhesive capsulitis, particularly in elderly patients. Early, gentle range of motion within a pain-free arc is crucial.
7. Bilateral Lesions: Failing to evaluate the contralateral side. Up to 60% of elastofibromas can be bilateral, though often only one is symptomatic. Missing a contralateral lesion could lead to future symptomatic presentation.