Orthopaedic · Radiology · Pathology Conference: Hand Mass in an 18-year-old Woman

History and Physical Examination

An 18-year-old woman was referred with a 1-month history of a small right hand mass. The mass was not painful and had not changed in color, shape, or size since she first discovered it. The patient denied numbness, paresthesias, and weakness of the right hand. There was no history of trauma or suggestion of infection. The patient denied other masses. Other medical and family history was noncontributory.

On physical examination, a discrete 1.5- × 1-cm soft, nontender mass was palpated at the proximal aspect of the volar palm between the long and ring metacarpals. An associated palpable thrill was not seen. There was no warmth, erythema, or surrounding edema. Range of motion, strength, and neurovascular examination of the hand were normal. No other masses were palpated on general examination, and there was no lymphadenopathy. The remainder of the physical examination was noncontributory.

Anteroposterior (AP) and lateral plain radiographs (Fig. 1) and MRI scans (Figs. 2, 3) of the right hand were obtained before referral.

Fig. 1A–B.

(A) AP and (B) lateral plain radiographs of the right hand show no bony or soft tissue abnormalities.

Fig. 2.

An unenhanced T2-weighted fat-saturated sagittal MR scan shows a 2- × 1-cm heterogeneous mass with smooth, rounded borders at the base of the proximal phalanx slightly compressing the flexor tendons.

Fig. 3A–B.

(A) A contrast-enhanced T2-weighted fat-saturated axial MR image and (B) an unenhanced T1-weighted fat-saturated axial MR scan show a heterogeneous mass with smooth, rounded borders compressing the flexor tendons. The mass enhances with contrast but is also bright on T1-weighted imaging, suggesting the presence of adipose tissue.

Based on the history, physical examination, and radiographic studies, what is the differential diagnosis?

Imaging Interpretation

Plain radiographs (Fig. 1) of the right hand were normal. MRI (Figs. 2, 3) of the right hand was performed with a 1.5-T magnet using multiple axial, coronal, and sagittal sequences before and after administration of Omniscan^® contrast (General Electric Healthcare, Princeton, NJ, USA). A vitamin E marker was positioned in the palm, superficial to the mass, before obtaining the images. An unenhanced T2-weighted fat-saturated sagittal MR scan (Fig. 2) and a contrast-enhanced T2-weighted fat-saturated axial MR scan (Fig. 3A) showed a 15-mm × 17-mm × 7-mm volar mass at the level of the proximal palm between the long and ring metacarpals. The mass enhanced vividly with contrast and appeared to extend to the flexor tendons. The mass appeared heterogeneous, with areas of greater enhancement centrally and peripherally. Three sequential images of an unenhanced T1-weighted fat-saturated axial MR scan (Fig. 3B) again showed the heterogeneous mass adjacent to the flexor tendons and suggested a relationship between the mass and the superficial palmar arch.

Differential Diagnosis

• Kimura’s disease

• Angiolymphoid hyperplasia with eosinophilia

• Neurofibroma

• Synovial sarcoma

• Giant cell tumor of tendon sheath

• Schwannoma

Given the lack of a concrete diagnosis, the lesion was biopsied. A 3-cm vertical incision was made over the volar palm in the region of the mass and carried down to the palmar fascia. On deeper dissection, the ulnar neurovascular bundle was identified. A pink, rubbery mass appeared to be emanating from the superficial palmar arch. An excisional biopsy of the mass was performed and the specimen underwent pathologic examination.

Histology Interpretation

Histologic examination revealed vascular proliferation with a prominent infiltrate of inflammatory cells rich in eosinophils and lymphocytes present in the background (Fig. 4). On higher magnification, plump epithelioid-appearing endothelial cells having rounded nuclei and abundant acidophilic cytoplasm were seen (Fig. 5). Immunohistochemical staining for CD31 highlighted the vessels.

Fig. 4.

A low-power photomicrograph of a histologic section shows (in the center) vascular proliferation and surrounding heavy inflammatory infiltrate rich in lymphocytes and eosinophils (Stain, hematoxylin and eosin; original magnification, ×100).

Fig. 5.

A high-power photomicrograph of a histologic section shows proliferated vessels with plump, epithelioid-appearing endothelial cells and numerous eosinophils and lymphocytes surrounding the vessels (Stain, hematoxylin and eosin; original magnification, ×400).

Based on the history, physical examination, radiographic studies, and histologic picture, what is the diagnosis and how should this lesion be treated?

Diagnosis

Angiolymphoid hyperplasia with eosinophilia

Discussion and Treatment

Based on the history of a small subcutaneous growth in the volar palm, the physical examination confirming the presence of a palpable mass, imaging consistent with the mass being of vascular etiology, and a histologic specimen showing plump epithelioid-appearing endothelial cells with peripheral eosinophilia and positive CD31 staining, a diagnosis of angiolymphoid hyperplasia with eosinophilia (ALHE) was made. Ultimately, the histology was central to reaching this diagnosis, as ALHE is diagnosed primarily by microscopic tissue evaluation.

Other potential diagnoses in this case included Kimura’s disease, neurofibroma, synovial sarcoma, giant cell tumor of tendon sheath, and schwannoma. Each of these diagnoses differs from ALHE in one or more distinct ways. Kimura’s disease is a chronic inflammatory condition that typically presents as a swelling, usually in the head or neck region. It often is confused with ALHE largely because of a similar histologic appearance. Although both have blood vessels lined by endothelial cells with perivascular infiltration of eosinophils, ALHE is unique in that its endothelial cells are characteristically plump; the endothelial cells in Kimura’s disease are much flatter. A second key difference between ALHE and Kimura’s disease is that the latter typically affects deeper tissues, such as lymph nodes and salivary glands, than the former [10].

We also considered neurofibroma, a benign tumor of peripheral nerve sheath origin. Neurofibromas occur most commonly as a solitary lesion but can occur in multiples, as in the disease neurofibromatosis (NF-1). Although a neurofibroma can present as a painless mass in the hand, it has a distinct histologic appearance characterized by bundles of spindle cells in the presence of nerve fibers [2]. Like ALHE, it may appear as a round heterogeneous mass on MRI; however, it should not enhance with contrast as vigorously as ALHE.

Synovial cell sarcoma was another possible diagnosis. It is one of the most common soft tissue sarcomas in young patients aged 15 to 40 years and occurs frequently in the hand [7]. Like a neurofibroma, it is very different from ALHE histologically, with biphasic synovial cell sarcomas exhibiting epithelial and spindle cells and monophasic only spindle cells. On MRI, synovial cell sarcoma can appear similar to ALHE but typically affects deeper tissues and is more likely to involve underlying bone.

Another consideration was giant cell tumor of the tendon sheath, a benign reactive lesion commonly involving the hand [3]. As in the case of our patient, a giant cell tumor of the tendon sheath can present as a painless mass in the hand with little or no findings on plain radiographs; however, it can be distinguished by its unique histologic features, which consist of multinucleated giant cells, polygonal mononuclear cells, and histiocytes [3]. Like ALHE, it may appear as a round heterogeneous mass on MRI but does not enhance with contrast as vividly as ALHE.

Our final consideration was schwannoma, a benign peripheral nerve sheath tumor that originates from the Schwann cell. In addition to the head and neck, it occurs commonly in the volar palm and forearm. Although it may appear similar to ALHE on MRI, it differs markedly in its histologic features. Microscopic analysis reveals areas of densely packed spindle cells arranged in a palisade-like pattern (Antoni Type A) alternating with regions of sparse spindle cells and a predominant myxoid stroma (Antoni Type B) [2].

ALHE, also known as epithelioid hemangioma, is a rare benign vascular neoplasm usually found on the face or scalp. It can occur on the hands, although this is rare; there are only a few case reports describing it in such a location [4–6, 8, 9]. ALHE has a female predominance, typically affects individuals 20 to 40 years old, and is most commonly seen in Asians [1, 9]. Although a benign disease process, it can be difficult to eradicate.

Patients with ALHE usually present with a painful papule or nodule. It is typically dome-shaped and appears erythematous to brown. It seldom is pulsatile [1, 10, 11]. Plain radiographs are unlikely to detect any abnormality; however, MRI may show a nodular heterogeneous mass just below the dermis that enhances with contrast, as occurred in this case. Approximately 20% of patients will have a peripheral blood eosinophilia. Our patient’s serum eosinophil level was not tested. Histologically, one typically sees plump endothelial cells, blood vessel proliferation, lymphocytes, and eosinophils. Immunohistochemical staining is often positive for CD31, an endothelial cell marker [1, 10, 11].

The mainstay of treatment for ALHE is surgical resection of the entire mass [5]. Topical or intralesional steroids, radiation, and cryotherapy also have been used with mixed results [9]. Although there is no risk of metastasis of ALHE, this disease has a tendency to recur locally, especially if not treated appropriately.

Our patient presented with a mass about the hypothenar region. The mass emanated from the superficial arch and could not be dissected from the ulnar artery. Ligation of the ulnar artery was necessary for complete excision. Good blood supply of the hand was noted on deflation of the tourniquet and no arterial reconstruction was required. Postoperatively, the patient wore a soft dressing and had no weightbearing limitations. She is currently 1 year postoperative and doing well with full hand and wrist function and no signs of disease recurrence.

Our case report is unique in that it describes a rare tumor in an even rarer location. There are only a handful of case reports describing ALHE in the hand. Although it may be rare, ALHE is a diagnosis that every orthopaedic surgeon should keep on his or her differential.