Rhabdomyomatous Mesenchymal Hamartoma: A Deep Subcutaneous Lesion in the Sternoclavicular Area

Abstract

Cutaneous rhabdomyomatous mesenchymal hamartoma (RMH) is a rare benign tumor composed of two or more types of mesenchymal-derived cells. RMHs are generally sporadic and independent, but they can be associated with congenital abnormalities. We report a subcutaneous case of RMH in the sternoclavicular area with two recurrences after complete surgical excision. The course is variable and can range from spontaneous resolution to repeated recurrences.

Hamartomas and midline anomalies in association with infantile hemangiomas, PHACE, and LUMBAR syndromes

“…In a report of twenty‐four patients with RMH, six (25%) had associated congenital anomalies, including cleft lip and palate, ocular anomalies, digit anomalies, thyroglossal duct sinus, and Delleman's syndrome . Although a few cases of RMH associated with IH have been reported, to the best of our knowledge RMH has never been reported in association with PHACE syndrome . In this series, we report the new association of RMH with PHACE syndrome.…”

Spontaneous Regression of a Plaque‐Type Striated Muscle Hamartoma

“…) . The etiology of SMH is unclear, although it has been suggested that an abnormality in the migration of embryonic mesodermal tissues may be involved . The cause of regression of SMH is also unknown.…”

“…Historically, treatment has consisted of surgical excision, but SMH resembling scleroderma en coup de sabre of the chin and a subcutaneous SMH in the sternoclavicular area recurred after surgical excision .…”

“…It is important to highlight associated congenital anomalies, including cleft lip, microtia, thyroglossal duct cyst, occult spinal dysraphism, and Delleman's syndrome, arising in the setting of SMH . Therefore, systemic examination to exclude other findings is essential .…”

“…Striated muscle hamartoma (SMH), or rhabdomyomatous mesenchymal hamartoma, is a rare, benign, congenital or acquired tumor . Surgical intervention is the therapeutic approach , but recent cases with recurrence after complete surgical excision and anecdotal spontaneous regressions have been documented in the medical literature .…”