Case prepared by Dr Naushin Ghori. Edited by Dr Jitendra Nasit
DETAILED CASE HISTORY:
- A 35-year-old female presents with skin lesions over left side upper back, which are associated with intermittent itching and dull aching pain for five years.
- Clinical examination revealed multiple small plaque-like, papulo-nodular brownish lesions on skin with underlying mass of approximately 5×4 cm in size. Ultrasound showed a possibility of vascular neoplastic etiology. Magnetic resonance imaging favors soft tissue tumor, the possibility of aggressive lesion is likely.
- Initially, a skin biopsy was received for diagnostic purpose.
Skin biopsy images:
- Skin biopsy shows small ulceration with unremarkable epidermis in the adjacent area. The reticular dermis shows few irregular dilated thin-walled vascular channels with prominent hobnail endothelial cells. NO areas of complexity, anastomosing pattern, multi-layering of endothelial cells, significant atypia, or mitoses are seen.
- The possibility of low-grade vascular tumor like hobnail/retiform hemangioendothelioma was raised based on these findings, in view of clinical and radiolgy impression.
- It is not possible to rule out a possibility of a malignant lesion in a small biopsy, so a frozen section was planned to look for malignant features in the other areas of the lesion.
Frozen section images:
- Frozen tissue shows mainly adipose and some dense colalgenised tissue with few variable-size thin-walled dilated vascular channels, without atypia in the endothelial cells. NO worrisome features are seen in the frozen section. Following frozen tissue evaluation, wide local excision was done.
- The epidermis shows ulceration at one place, otherwise unremarkable.
- The underlying dermis and subcutis show variably sized dilated irregular and elongated narrowed and compressed arborizing and some branching vascular channels.
- These vascular channels are lined by a single layer of mildly enlarged endothelial cells with minimally hyperchromatic hobnailed nuclei projecting into the lumen. This pattern of growth resembles that of rete testis. Only occasional mitoses are seen. The background is fibrotic in appearance.
- Focal collection lymphoid aggregates are seen (blue arrow).
- Overall tumor border is circumscribed and smooth, without infiltrative appearance.
- In the present case, some areas have papillary-like intraluminal projections with hyalinized cores, which are lined by a single layer of endothelial cells with hobnail nuclei, suggestive of papillary intralymphatic angioendothelioma (Dabska tumor). Few primitive glomeruloid like structures are also seen (yellow circle).
- Immunohistochemistry shows positivity for CD34 and CD31 (not shown here).
Practical points of Pathoclinics:
- Retiform hemangioendothelioma (hobnail hemangioendothelioma) is an uncommon vascular tumor of intermediate grade malignancy, which is prone for local recurrence but rarely metastasized to the distant sites. It is equivalent to a low-grade angiosarcoma.
- Retiform hemangioendothelioma commonly involves the skin and subcutaneous tissue of the lower extremities in children and young adults and commonly presents as a slow growing, asymptomatic tumor mass. However, patients over a wide age range can be affected. Uncommon sites of involvement include the head and neck region, trunk, penis, and pleura. Clinically, slow-growing multiple plaques and nodules are seen on the skin.
- In the present case, tumor was slowly enlarging over a period of 5 years, without significant symptoms.
- On immunohistochemistry, CD31, CD34, and factor VIII-related antigen are positive, while podoplanin (D2-40) and vascular endothelial growth factor receptor-3 (VEGFR-3) are negative.
- Retiform hemangioendothelioma should be treated with wide local excision. Local recurrences are common (in approximately 60% of cases) if not completely excised. Very rare metastases to the regional lymph nodes have been reported.
- Areas of endovascular papillary angioendothelioma (Dabska tumor) can be seen in retiform hemangioendothelioma. Dabska tumor share many clinical features with retiform hemangioendothelioma, like skin and subcutis involvement and young age group. In addition, both are in intermediate category of vascular lesions. Microscopically, variable size intercommunicating vascular channels, lined with flattened plump and epithelioid to distinctly columnar cells. Papillary tufts of endothelial cells (primitive glomeruloid like structures) with a central avascular hyaline core are common. However, Dabska tumors do not show prominent rete-like elongated vessels. Dabska tumor is positive for podoplanin (D2-40), and vascular endothelial growth factor receptor-3 (VEGFR-3), in addition to CD31, CD34, factor VIII-related antigen.
- Antonescu Cr et al showed that few cases of retiform hemangioendothelioma and composite hemangioendothelioma have YAP1 gene rearrangements and YAP1-MAML2 fusion, suggesting a close relationship between these two.
- Retiform hemangioendothelioma may have an atypical presentation and it should be carefully differentiated from angiosarcoma (commonly seen in older age group, with history of mastectomy and irradiation, multi-layered atypical spindled or epithelioid endothelial cells, anastomosing complex vascular pattern, infiltrative border features, frequent mitoses), composite hemangioendothelioma (combination of 2 or more distinct hemangioendothelioma) and Kaposi sarcoma (search for HIV, look for small, slit-like vascular spaces containing RBCs, which are lined by spindle cells. HHV8+).
- Chundriger Q, Tariq MU, Rahim S, Abdul-Ghafar J, Din NU. Retiform hemangioendothelioma: a case series and review of the literature. J Med Case Rep. 2021 Feb 17;15(1):69. doi: 10.1186/s13256-021-02671-2. PMID: 33593408; PMCID: PMC7887779.
- Antonescu CR, Dickson BC, Sung YS, Zhang L, Suurmeijer AJH, Stenzinger A, Mechtersheimer G, Fletcher CDM. Recurrent YAP1 and MAML2 Gene Rearrangements in Retiform and Composite Hemangioendothelioma. Am J Surg Pathol. 2020 Dec;44(12):1677-1684. doi: 10.1097/PAS.0000000000001575. PMID: 32991341; PMCID: PMC7773139.