Are You Confident of the Diagnosis?
Dabska tumors are rare tumors reported most often in children. These lesions are usually noted by the parents of patients as a growing mass of tissue. Dabska tumors may occur congenitally or may grow from a preexisting benign vascular lesion.
Characteristic findings on physical examination
Often Dabska tumors are firm flesh-toned masses, but when abundant engorged blood vessels are present, they may appear blue or pink. Lesions have a wide range of reported sizes depending on the body site and the extent of tumor growth. When these tumors are submitted for histologic examination, they show abundant, variably sized, thin-walled vessels with characteristic hobnail endothelial cells. These tumors dissect through the dermis and subcutaneous tissue as they grow. Intraluminal projections from the vascular wall are present, forming a papillary intravascular architecture.
Expected results of diagnostic studies
These collections of papillary projections are commonly referred to as “rosettes.” The papillary cores contain abundant collagen type IV. Often vessels are surrounded by a lymphocytic inflammatory infiltrate. High levels of vascular endothelial growth factor (VEGF)-3 and immunostaining for D2-40 have been found in the endothelial component of these lesions, suggesting that Dabska tumors are likely lymphatically derived.
Angiosarcomas may present in a similar manner as Dabska tumors, but they are very rare in children. When submitted for histologic examination, angiosarcomas contain cytologic atypia not seen in Dabska tumors and lack hobnail endothelial cells. The overall architecture of angiosarcomas is also much more haphazard and pleomorphic.
Retiform hemangioendotheliomas are another vascular tumor with nonspecific clinical presentation. These lesions more commonly affect adult patients. Upon histologic evaluation, lesions contain hobnailing but fail to form the well formed rosettes seen in Dabska tumors.
Infantile hemangiomas are benign vascular tumors that may appear clinically identical to a Dabska tumor. Upon histologic examination, they are formed from well differentiated ordinary-appearing vascular channels.
Hobnail hemangiomas histologically contain hobnailed endothelial cells but do not contain papillary projections and do not invade the subcutaneous tissue.
Who is at Risk for Developing this Disease?
Dabska tumors occur most commonly in young children. Only about 25% occur in adults. These lesions are rare and no risk factors have been identified.
What is the Cause of the Disease?
No known cause for this tumor has been identified.
The cause of Dabska tumors remains unknown. Recent research in the area has demonstrated that these tumors most likely have lymphatic differentiation. VEGF-3 (a lymphatic marker) has been demonstrated in high levels within the endothelium of the vascular channels. Additionally immunostaining with D2-40, which targets a glycoprotein found in lymphatics, demonstrates positivity within these tumors. Whether Dabska tumors represent a unique tumor of the lymphatic system or a group of similar appearing neoplasms is unclear and continues to be studied.
Systemic Implications and Complications
Dabska tumors represent a low-grade vascular malignancy with aggressive local invasion and some degree of metastatic potential. Dependent on the location of the tumor, underlying and adjacent structures may be compromised. This may lead to deformity and local destruction. Additionally, several cases of regional lymph node and distant metastasis have been described, leading to the death of several patients reported in early descriptions. In more recent publications, the tumors have had a more benign behavior. The early descriptions may instead represent well differentiated angiosarcomas, but as this is a rare condition, additional reports continue to help define the severity of this malignancy.
Wide local excision is the treatment of choice for these poorly defined vascular tumors. If nodal spread is suspected, lymph node dissection should be completed. Additionally, appropriate imaging should be completed to search for distant metastasis.
Optimal Therapeutic Approach for this Disease
Wide surgical excision with margin of 2 cm is essential in treatment of patients with a Dabska tumor. Tumors have a tendency to recur, even after wide local excision, so long-term clinical follow-up is indicated for these patients.
Long-term routine physical examinations after surgical excision should be completed for these patients. Any systemic symptoms that may indicate distant metastasis should be investigated.
Unusual Clinical Scenarios to Consider in Patient Management
This is a very rare childhood tumor, and all clinical manifestations are unique to the individual. As such, multidisciplinary care and communication between specialists is essential for appropriate patient care.
What is the Evidence?
Fanburg-Smith, JC, Michal, M, Paranen, TA, Alitalo, K, Miettinen, M. “Papillary intralymphatic angioendothelioma (PILA): a report of 12 cases of a distinctive vascular tumor with phenotypic features of lymphatic vessels”. Am J Surg Pathol. vol. 23. 1999. pp. 1004-10. (This reference discusses the lymphatic staining characteristics of this tumor. Detailed discussion of the histologic findings and probable lymphatic differentiation are presented.)
Fukunaga, M. “Endovascular papillary angioendothelioma (Dabska tumor)”. Pathol Int. vol. 48. 1998. pp. 840(This article discusses the histologic findings of Dabska tumors and discusses the possibility that these tumors may represent a set of similar appearing vascular tumors of different etiologies.)
Fukunaga, M. “Expression of D2-40 in lymphatic endothelium of normal tissues and in vascular tumours”. Histology. vol. 46. 2005. pp. 396-402. (This reference discusses the staining pattern of Daska tumors with D2-40.)
Schwartz, RA, Dabski, C, Dabska, M. “The Dabska tumor: a 30 year retrospective”. Dermatology. vol. 201. 2000. pp. 1-5. (This article presents a comprehensive review of Dabska tumors.)
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