Left Middle Phalanx Tuberculous Dactylitis Masquerading as a Tumor: First Case Report in Saudi Arabia

Summary:

Tuberculous dactylitis can cause osteomyelitis, which is a rare extrapulmonary manifestation of tuberculosis, often misdiagnosed due to its nonspecific presentation and resemblance to other conditions like neoplasms. A 15-year-old male patient reported to our clinic with a 1-year history of left index finger pain and swelling following a football-related injury. Despite conservative management, the symptoms had progressively worsened over the past few months. Clinical examination revealed deformity and swelling of the middle phalanx, along with induced pain on range of motion. Bacteriological analysis indicated polymorphic nuclear cells and the presence of coagulase-negative Staphylococcus (Staphylococcus hominis). Radiographic evaluation, including x-ray and magnetic resonance imaging, revealed medullary expansion, trabecular thinning, and focal soft tissue swelling. Magnetic resonance imaging displayed extensive soft tissue and bone marrow involvement, raising concerns of a tumor. An open biopsy was performed, yielding unexpected findings of necrotizing and suppurative granulomatous inflammation, strongly suggesting an ongoing infectious process. The subsequent Quantiferon TB Gold Test confirmed tuberculosis infection. Treatment encompassed debridement, synovectomy, and initiation of an antituberculosis regimen. The patient showed significant improvement after treatment. Timely diagnosis and treatment of tuberculous dactylitis are crucial, as highlighted by the patient’s positive response to combined surgical and pharmacological intervention, despite initial diagnostic challenges.

Tuberculosis (TB) has been recognized as a disease with various kinds of mimicry clinical manifestations which often result in misdiagnosis. Skeletal involvement associated with TB was seen in 1%–3% of patients and approximately 10%–20% of extra pulmonary cases.¹ Almost one-half of these cases affected the spine, and the remaining were extraspinal osteoarticular joints.^1,2 Furthermore, it was indicated that the knee is the third most common musculoskeletal site followed by the spine and hip. Masquerading manifestations of TB become a hindrance in diagnosing it, especially in extra pulmonary TB.¹ Digital tuberculosis is a rare presentation. Diagnosing digital TB can be challenging due to several factors including traumatic masking and the nonspecificity of clinical and radiological signs.² This condition, which involves the small bones of the hand, is an uncommon yet significant manifestation of tuberculosis outside the lungs.³ The historical context of tuberculous dactylitis dates back to the late 19th century. Feilchenfeld⁴ first described its radiographic appearance in children, and a decade earlier, Rankin used histological methods to identify this condition. Known also as spina ventosa, tuberculous dactylitis features a distinctive process where the cortical bone gradually deteriorates near the medullary canal, leading to an increase in subperiosteal hyperplasia. For managing this condition, the World Health Organization recommends a dual strategy focusing on conservative treatment with antituberculous medications for both skin and extrapulmonary tuberculosis. This case report has been reported in line with the Surgical Case Report Criteria.⁵

CASE PRESENTATION

This is a case of a 15-year-old male patient who presented to the clinic complaining of pain and swelling in the left index finger, as shown in Figure 1. The condition started 1 year ago after an injury while playing football; however, the patient sought conservative treatment without any improvement until his visit to the clinic a year later. The pain and swelling both had been progressively worsening in the last couple of months. Physical examination showed swelling and deformity of the middle phalanx of the left index finger and induced pain upon range of motion. Multiple laboratory tests were ordered. Supplemental Digital Content 1 demonstrates the abnormal laboratory results. [See table, Supplemental Digital Content 1, which displays a detailed overview of the abnormal laboratory results alongside the Quantiferon TB Gold test results for the patient. It includes significant findings from the complete blood count, erythrocyte sedimentation rate (ESR), special chemistry tests, and blood culture, which indicated an infection. Additionally, the table shows the results from the Quantiferon TB Gold test, which are critical for diagnosing tuberculosis in the context of the clinical presentation. http://links.lww.com/PRSGO/D484.]

Fig. 1.

The left index finger of the patient is shown with a swelling and fungating lesion in the middle phalanx over the distal interphalangeal joint upon first presentation.

Bacteriology report of the patient’s body fluid sample resulted in +1 polymorphic nuclear cells and +1 epithelial cells were seen. The culture result showed scanty growth of coagulase-negative Staphylococcus (Staphylococcus hominis). Similarly, a sample taken from the wound demonstrated the same findings.

Additionally, magnetic resonance imaging (MRI) without contrast using different pulse sequences revealed significant progression of the extending lesion replacing the bone marrow of the middle phalanx of the left index finger as well as the extent of the soft tissue extension in the subcutaneous tissue and intraarticularly in the proximal interphalangeal joint. There was remarkable extension beneath the flexor and extensor tendons with denovo abnormal marrow signal along the proximal phalanx. Furthermore, the lesion showed cortical breaks with nonspecific signal intensity showing hypointensity in T1 sequence and hyperintensity in T2 and fluid sensitive sequences as seen in Figure 2. The rest of the osseous and musculocutaneous components were unremarkable with no other joint affection noted. The impression given noted a locally aggressive osseous lesion leading to the suspicion of the presence of a tumor. Posterior chest radiography revealed normal chest examination with no active disease.

Fig. 2.

MRI of the initial visit denoting localized bone lesion on the dorsal aspect of left index finger.

Upon initial presentation, the patient exhibited a fungating lesion on the left index finger, which raised a significant concern for a malignant osseous tumor, as indicated by MRI findings. Consequently, an open biopsy was urgently performed to ascertain the nature of the rapidly progressing lesion. Specimens from the bone lesion, volar aspect tissue, and a dorsal subcutaneous lesion tissue were collected and sent for comprehensive histopathological analysis. The primary suspicion was of a neoplastic origin, hence the immediate need for a biopsy to facilitate a rapid diagnosis and appropriate management plan. The collected samples from the bone lesion included two soft tissue fragments measuring 1 × 0.6 × 0.4 cm. Surprisingly, the histopathological examination revealed necrotizing and suppurative granulomatous inflammation in all three biopsy specimens, as depicted in Figure 3. These findings were unexpected and suggested an ongoing infectious process rather than a neoplastic disease. The presence of granulomatous inflammation raised suspicions of a possible tuberculosis infection, which led to further confirmatory tests. A Quantiferon TB Gold Test was subsequently performed, and the results were positive, confirming tuberculosis as the underlying cause of the lesions. (See table, Supplemental Digital Content 1, http://links.lww.com/PRSGO/D484.)

Fig. 3.

Histopathology from the biopsies revealed necrotizing and supportive granulomatous inflammation indicating an ongoing infectious process and a suspected tuberculosis infection.

Open debridement and synovectomy were performed on the left index finger. The infectious diseases unit was consulted, and ceftriaxone 2G once daily was started by an intravenous route. Additionally, teicoplanin 800 mg IV twice a day for 2 days was started, followed by a decrease in frequency to once daily. A week later, the patient was started on a TB regimen: isoniazid 300mg, rifampicin 600 mg, pyrazinamide 2500 mg, and levofloxacin 750 mg daily by oral route (Fig. 4), after 1 month of treatment. Serial postoperative x-rays were performed, revealing an absence of complications throughout the monitoring period. The patient was doing well, and he was discharged with advice to maintain a regular follow-up.

Fig. 4.

The swelling was reduced significantly after one month of treatment.

DISCUSSION

In our case, we emphasize the distinctive presentation of tuberculous dactylitis causing tuberculous osteomyelitis with minimal arthritis, commonly known as spina ventosa in the left index finger of a pediatric patient. Despite the disease’s endemic nature in the region,² our case marks the first time such an instance is reported in Saudi Arabia. The initial complaint of our 15-year-old male patient was pain and swelling in the left index finger, stemming from a football-related injury for which he did not seek medical advice until a year later. He was diagnosed with tuberculous dactylitis, causing tuberculous osteomyelitis.

Given the patient’s youth, subtle symptoms, and gradual progression, the initial clinical suspicion leaned toward a neoplastic growth, specifically osteosarcoma.⁶ This diagnostic dilemma, where TB masquerades as osteosarcoma, is not unprecedented, as seen in the report by Janssen et al,⁷ which detailed a patient initially misdiagnosed with osteosarcoma but later found to have tuberculous arthritis. What made the diagnosis of tuberculous osteomyelitis even more unlikely were the patient’s symptoms. The patient’s pain and swelling were not accompanied by night sweats, weight loss, fever, or any contact with a TB patient. The patient with tuberculous osteomyelitis did not present with fever. Additionally, our patient showed only mild increases in ESR and C-reactive protein levels, aligning with patterns observed in the broader literature on the condition. An interesting comparison can be made with the case documented by Sahli et al,⁸ where a patient with tubercular osteoarthritis exhibited swelling in the big toe of the left foot. The diagnostic blood tests for this patient revealed an elevated ESR of 48 mm per hour, signaling a mild increase in inflammation markers. This elevation, however, was attributed to active synovitis due to the patient’s rheumatoid arthritis, leading to a delayed diagnosis. X-rays of the left finger done on our patient showed medullary expansion and trabecular thinning of the middle phalanx of the left index finger. In addition, focal soft tissue swelling opposite the dorsal aspect of the distal interphalangeal joint was observed with narrowing of the joint space. Cahill et al⁹ reported a case of tuberculous dactylitis where the initial x-ray revealed erosion at the bony cortex of the distal end of the proximal phalanx. This finding suggested osteomyelitis and pointed to significant underlying pathology, emphasizing the complexity of the case and necessitating further investigation to fully understand the patient’s condition. In the early stages of tuberculous dactylitis, imaging might show normal features, yet as the disease progresses, MRIs become crucial for diagnosis. Highly sensitive in detecting tuberculous osteomyelitis, MRI scans can reveal detailed anatomical and potential inflammatory changes such as edema and fluid accumulation in the bone and surrounding soft tissue. These changes are visible in both coronal and sagittal views using T1 and T2-weighted sequences. Diagnosis established through an integrated approach that included medical history, physical examination findings, laboratory results, and comprehensive imaging studies, alongside histopathological analysis, polymerase chain reaction, and radiological assessments. However, polymerase chain reaction assay demonstrates a sensitivity and specificity reaching 100% in cases with multibacillary presentations, which diminishes in scenarios involving paucibacillary conditions. In accordance to this, an open biopsy was performed and the specimens were sent for histopathological analysis, which showed necrotizing and suppurative granulomatous inflammation, pointing toward TB. To confirm this, a Quantiferon TB Gold test was performed, which returned positive. The Quantiferon TB Gold test used here has higher sensitivity and specificity while providing results in a lesser time than the more traditional tuberculin skin test, which can provide false positives in cases of vaccinated patients.¹⁰ As far as medical treatment is concerned, there are no particular guidelines on managing extrapulmonary TB. Hence, it is surgical management such as synovectomy for treatment of pulmonary TB where antitubercular medications like isoniazid, rifampicin, and pyrazinamide are used.¹¹ In our case, we used a similar approach; however, before starting the antitubercular medications, open debridement and synovectomy were performed on the left index finger, and to prevent infections, ceftriaxone and teicoplanin were also prescribed. According to the established literature, the treatment protocol for tubercular dactylitis, particularly involving small joints, generally recommends nonoperative management initially, focusing on antitubercular medications (ATT). This approach is preferred because surgical intervention might often be unnecessary due to the potential for significant clinical and radiological improvement with ATT alone. Furthermore, deferring surgery can also prevent complications such as the formation of tubercular sinuses, which are rare when surgery is postponed following an adequate course of ATT. However, our case deviated from the typical presentation and treatment pathway due to several compelling clinical features. The patient presented with an open, fungating lesion which was rapidly progressing and resembled a malignant tumor both clinically and on MRI evaluations. Such an aggressive and atypical presentation raised legitimate concerns over a possible neoplastic process, which necessitated a different diagnostic and therapeutic approach. Consequently, the decision to perform an open biopsy before initiating antitubercular treatment was driven by the urgent need to clarify the nature of the lesion. This was essential not only to rule out a potential tumor but also to determine the appropriate management strategy in the context of the lesion’s unusual characteristics and rapid progression. This approach was aligned with the best practices for managing potentially malignant lesions where immediate histopathological investigation is critical for guiding treatment decisions; some papers follow the same approach.¹¹ Thus, although the initial nonoperative treatment for tubercular dactylitis is supported by the literature, our case required deviation from this protocol due to unique clinical imperatives that prioritized ruling out malignancy to ensure the patient’s safety and optimal care. Our case report’s illustrative content, particularly the MRI images in Figure 2, presents a limitation due to the use of different MRI sequences (T1 and T2). These were chosen for their clinical relevance but limit direct visual comparison. Due to constraints in available imaging data, providing consistent image types for a comparative analysis was not feasible. This limitation is highlighted to clarify the context in which these images supported our clinical decision-making process.

CONCLUSIONS

This case underscores the diagnostic complexities of tuberculous dactylitis, particularly in its resemblance to neoplastic conditions such as osteosarcoma, and highlights the importance of a multidisciplinary approach in the diagnosis and management of this rare form of extrapulmonary TB. Despite the absence of classical systemic symptoms and with only mild elevations in inflammatory markers, thorough clinical evaluation, imaging studies, and histopathological examination were pivotal in reaching a conclusive diagnosis. The case also demonstrates the efficacy of conventional antitubercular therapy complemented by surgical intervention, underscoring the adaptability of treatment protocols to individual patient presentations. It serves as a reminder of TB’s potential to present in atypical locations and forms, advocating for heightened clinical vigilance and consideration of TB in differential diagnoses, even in regions where the disease is not endemic. Continued follow-up and monitoring were critical in this patient’s recovery, indicating the value of long-term management in achieving favorable outcomes in tuberculous osteomyelitis.

DISCLOSURES

The authors declare no financial interests or commercial associations that could pose or create a real or perceived bias in relation to the content of this article. Specifically, the authors have no employment, stock ownership, consultancy roles, honoraria, patents, or funding related to the subject of this article. All potential conflicts of interest for the author group have been disclosed and no new conflicts have arisen since submission.