Dermoscopic findings of a congenital smooth muscle hamartoma in an infant.

Cutaneous smooth muscle hamartoma is an uncommon, benign tumor developing in the dermis as a result of disorganized hyperproliferation of arrector pili muscle fibers. We present a 1-month-old infant with a congenital smooth muscle hamartoma together with the dermoscopic findings of the case. Dermoscopy can be a helpful non-invasive tool in diagnosing congenital smooth muscle hamartoma due to its distinct findings that help to differentiate it from close mimickers like solitary mastocytoma.

Congenital Smooth Muscle Hamartoma with Follicular Spotted Appearance / 대한피부과학회지

A congenital smooth muscle hamartoma is a rare benign cutaneous abnormality and histologically characterized by smooth muscle hyperplasia with a great number of long and straight bundles of smooth muscle at various angles of the orientation, throughout the dermis. A congenital smooth muscle hamartoma usually presents as a congenital hairy patch or plaque with or without hyperpigmentation on the trunk or extremities. The congenital smooth muscle hamartoma with follicular spotted appearance is a rare clinical variant, and is appeared as a patch with marked follicular papules. Herein, we report a 16-year-old girl with this rare patch follicular variant of congenital smooth muscle hamartoma, on the left upper arm.

A Case of Congenital Smooth Muscle Hamartoma Presenting as a Human Tail / 대한피부과학회지

A human tail is a rare congenital anomaly, and is characterised by a prominent lesion from the lumbosacrococcygeal region. Human tails are classified into 'true tails' and 'pseudotails'. True tails are comprised of only mesenchymal tissue. They are presumed to be remnants of the embryologic tail. All other lumbosacrococcygeal protrusions are summarized as pseudotails. Congenital smooth muscle hamartoma usually presents as a well-circumscribed, hypertrichotic, hyperpigmented or skin-colored patch or plaque on the trunk or an extremity at birth. Histologically, numerous thick, long, well-defined bundles of smooth muscle fibers are scattered throughout the dermis in various directions. We report a case of congenital smooth muscle hamartoma in a 15-year-old male patient who presented with a tail-like protruding mass accompanied by hypertrichosis and underlying soft tissue deviation.

Three Cases of Congenital Smooth Muscle Hamartomas

Congenital smooth muscle hamartomas (CSMHs) usually appear at birth as skin-colored or slightly hyperpigmented patches or plaques on the trunk or extremities and are often covered by and increased amount of vellus hair. Histopathologically, it represents a proliferation of smooth muscle bundles within the dermis(1,2). We herein report on three cases of localized CSMHs; Case 1 was a 2-month-old boy who presented with a skin-colored, 6x5cm-sized plaque with folds, hypertrichosis and pseudo- Darier's sign on the face, an unusual site. But there was no hyperpigmentation. Case 2 and 3 were both 1-month-old boys who presented with typical hyperpigmented, hairy plaques on the lateral aspect of the left thigh.

A Case of Congenital Smooth Muscle Hamartoma / 대한피부과학회지

Congenital smooth muscle hamartoma usually presents as a well-circumscribed, hypertrichotic, hyperpigmented or skin colored patch or plaque on the trunk or an extremity at birth. Histologically, numerous thick, long, well defined bundles of smooth muscle fibers are scattered throughout the dermis in various directions. We report a case of congenital smooth muscle hamartoma in an 8-month-old female infant who showed hypertrichotic, skin colored plaque on the lumbosacral area since at birth. The pseudo-Darier sign was positive. Histopathologic findings were numerous, well-defined bundles of smooth muscle fibers in the dermis (H and E, Masson-trichrome stain).

A Case of Congenital Smooth Muscle Hamartoma / 대한피부과학회지

Congenital smooth muscle hamartoma(CSMH), a rare congenital benign tumor of the skin, usually appears at birth as skin colored or slightly hyperpigmented patches or plaques, sometimes with lightly pigmented vellus hairs. Histopathologically it has a marked hyperplasia of well-demarcated smooth muscle bundles in the dermis. We report a case of CSMH in a 4-month-old male infant, who had had hypertrichosis, rippling and multiple light brown colored macules on both his lower extremites since birth. Histopathologically, markedly proliferated smooth muscle buildles were scattered throughout the retucular dermis.

A Case of Congenital Smooth Muscle Hamartoma / 대한피부과학회지

Congenital smooth musele hamartomas appear at birth as hypertrichotic patches or plaques with or without hyperpigmentation. Histologic characteristic is hyperplasia of dermal smooth muscle bundles. We report a case of congenital smooth muscle harnartoma in 5-year-old female, who showed localized excessive-hairy, skin-colored patch on the lateral surface of left. elbow, which were found at birth. Biopsy specimen showed hyperpigmentation of the basal layers of epidermis, melanophages in upper dermis, and hyperplasia of smooth muscle bundles in lower dermis.

A Case of Chondrodermatitis Nodularis Chronica Helicis / 대한피부과학회지

A 51-year-old man had small, tender, skin colored firm nodule on the helix of the both ears for eight months. He was found to have classic features of chondrodermatitis nodularis chronica helicis, namely, tender nodule less than 1 cm in length with central crusting, localization to helix, age, men, and histologic findings. The histologic examination of the biopsy specimen showed the presence of thinned epiderrnis on center. acanthosis on the adjacent epidermis, with hyperkeratosis and parakeratosis, and cleft between epidermis and dermis. In the dermis, highly vascularized connective tissue and chronic inflarnmatory infiltrate were visible with perichondrial fibrosis. Elastic tissue stain showed degeneration of elastic fibers. After complete excision, no recurrence was obsered until now.