Case Presentation: A 62-year-old woman with hypertension, carpal tunnel syndrome, and a year-long history of complex regional pain syndrome (CRPS) presented with chronic, severe right arm pain along with swelling and erythema. One year before this presentation, she had experienced right-hand numbness and tingling, leading to a carpal tunnel syndrome diagnosis and subsequent release surgery. Post-surgery, she had significant pain and swelling, and was diagnosed with CRPS. Despite treatments including antibiotics, ganglion stellate blocks, and physical therapy, her symptoms continued to worsen.On examination, her right upper extremity was swollen from fingers to distal arm, with erythema extending to the elbow. There was marked tenderness and no active range of motion in her fingers, wrist, or elbow. Initial lab work showed WBC 14.54, hemoglobin 11.2, platelet count 495, CK 21. ANA was negative. MRI of the forearm revealed diffuse soft tissue swelling from elbow to wrist, consistent with cellulitis, myositis, synovitis with joint effusion at the elbow, marginal marrow edema in the distal humerus.Consultations with vascular surgery, infectious disease, orthopedic surgery, and pain management were obtained. She was treated with cefazolin for cellulitis, and an elbow arthrocentesis was performed, yielding negative results. Her pain was refractory to high doses of opioids and neuromodulators, necessitating a lidocaine infusion.Due to the unusual progression of her case, a forearm biopsy was performed and revealed epithelioid hemangioendothelioma (EHE). She subsequently underwent right glenohumeral disarticulation with axillary lymph node dissection and was discharged to inpatient rehabilitation, with follow-up appointments scheduled in medical and radiation oncology.
Discussion: CRPS is a chronic pain disorder marked by pain that is disproportionate to the inciting event. Although its pathophysiology is unclear, CRPS is thought to result from an abnormal nervous system response to injury, causing hyperalgesia, allodynia, autonomic dysregulation, edema, and trophic changes. CRPS is classified into two subtypes: CRPS 1, which occurs without prior nerve injury, and CRPS 2, which follows an injury such as a fracture or surgery.Diagnosis relies on the Budapest criteria, which include a key requirement that no other diagnosis can explain the patient’s symptoms. Thus, it is essential for clinicians to exclude alternative diagnoses even if all other criteria are met. In this case, malignancy was not considered until a year after the patient’s CRPS diagnosis. Ultimately, a biopsy revealed EHE, a rare vascular tumor that often affects the bones, lungs, and liver. With few established guidelines due to it’s rarity, EHE has a variable prognosis, with a 64% mortality rate for cases with lung metastases. Unfortunately, at diagnosis, the patient already had lung and liver metastases.
Conclusions: This case underscores the importance of maintaining a broad differential when diagnosing conditions of exclusion, such as complex regional pain syndrome. Hospitalists should be vigilant in exploring potential underlying etiologies, especially when patients present with persistent or atypical symptoms. This ensures that serious conditions, such as epithelioid hemangioendothelioma in this case, are not missed. Thorough investigation prior to settling on a diagnosis of exclusion can prevent delays in critical diagnoses and improve patient outcomes.
