Perforating Calcinosis Cutis as a Complication of Intraosseous Fluid Infusion in the Setting of a Near-Drowning Event.

Iatrogenic calcinosis cutis represents a subset of calcinosis cutis resulting secondary to treatments or procedures. We present the first report of calcinosis cutis resulting from the intraosseous infusion and one of a few cases with associated transepidermal elimination. A previously healthy 2-year-old female presented with a new-onset unilateral shin rash 1 week following hospitalization for a near-drowning event. A dermatologic exam revealed multiple small, tender, firm, chalky-white papules with surrounding erythema, in addition to two erythematous macules superior and medial to the papular lesions, corresponding to prior intraosseous access sites. The rash persisted despite trials of topical mupirocin and acyclovir cream, prompting a referral to a dermatologist. An excisional biopsy was performed, revealing circumscribed dermal deposits of acellular basophilic material connected to the overlying epidermis through an invaginated keratin plug. A von Kossa silver stain highlighted the deposits, confirming the diagnosis of perforating calcinosis cutis. The lesions did not recur following the excisional biopsy. Iatrogenic calcinosis cutis may be seen as a complication of the infusion of calcium-containing fluids via intraosseous access, in addition to the more commonly observed peripheral intravenous access. Awareness of this disorder is important in order to distinguish it from an infectious mimic and guide the selection of therapy.

Malignant myopericytoma: Case report and review of the literature.

A 29-year-old male presented with a two-week history of a tender lesion on his right thigh. The lesion was a 1.5 cm erythematous nodule with overlying hemorrhagic crust. Histopathologic examination of a biopsy specimen revealed a highly cellular neoplasm with irregular vesicular nuclei, prominent nucleoli, and scattered mitotic figures. The cells within the lesion were rounded, ovoid and spindle shaped cells with perivascular growth. The architecture and staining pattern of the lesion were most consistent with a diagnosis of malignant myopericytoma, an exceedingly rare malignancy.

Squamous cell carcinoma or squamous proliferation associated with nivolumab treatment for metastatic melanoma.

Nivolumab is a programmed death-1 (PD1) immune checkpoint inhibitor that treats various types of cancers including non-small cell lung carcinoma and melanoma, among others. Although it serves as an effective immunotherapy, there are many associated immune-related adverse events. Even years after the introduction of nivolumab, the breadth of its side effect profile continues to expand. We present a case of squamous cell carcinoma associated with nivolumab treatment for metastatic melanoma.

Migrated Bulking Material (Solesta) Presenting as a Vaginal "Cyst": Histopathologic and Chemical Analytical Features.

Performing injections with a bulking agent consisting of nonanimal stabilized hyaluronic acid and dextranomer is a well-tolerated and efficacious treatment for mild to moderate fecal incontinence. Here, we discuss a case of a patient with a history of a bulking procedure for fecal incontinence who presented to the obstetrics/gynecology clinic for evaluation of a new vaginal "cyst," which was excised. Histopathologic examination revealed migrated bulking agent within the excised specimen.

Melanoma: An FP's guide to diagnosis and management.

This review details the latest recommendations on dermoscopy and excision techniques, indications for sentinel lymph node biopsy, and Tx options.

Cutaneous foreign body microemboli-induced occlusive vasculopathy: A complication of illicit intravenous injection of oral opioid tablets.

Occlusive nonvasculitic vasculopathy is a process characterized clinically by retiform purpura and potential ulceration and necrosis of affected areas, secondary to blockage of small vessels without associated inflammatory vasculitis. Intravascular injection of foreign material is known to cause distal ischemia and necrosis due to thrombosis, local vasoconstriction, or microemboli formation. A 27-year-old male presented with retiform purpura and worsening distal fingertip necrosis of the right upper extremity accompanied by suspicious intravascular polarizable foreign material identified on skin, muscle, and vascular biopsies. We report a case that highlights concerning complications and dermatopathologic findings of intravascular injection of oral opioid tablets.

Rhabdomyomatous mesenchymal hamartoma presenting as a chin nodule in a 15-year-old male.

Rhabdomyomatous mesenchymal hamartoma (RMH), also known as congenital midline hamartoma and striated muscle hamartoma, is a rare congenital malformation presenting most commonly in midline sites of the head and neck region. Since its first description in 1986, 67 cases have been reported to date. We report a case of RMH presenting as a chin nodule in an otherwise healthy 15-year-old male. The patient presented with a dome-shaped subcutaneous lesion on his chin which had been present since birth, but had grown and was interfering with his ability to shave. He otherwise had no history of congenital anomalies or malformations. Histopathological examination of the excised lesion revealed a haphazard proliferation of striated muscle admixed with adipose tissue and adnexal structures within the dermis and subcutaneous tissue, consistent with a diagnosis of RMH. While the majority of reported cases are of newborns or children under 3 years of age, RMH may not come to clinical attention until later in life. This rare malformation should be included in the differential diagnosis of lesions containing dermal striated muscle and/or adipose tissue, to include nevus lipomatosus superficialis, fibrous hamartoma of infancy, neuromuscular choristoma, fetal rhabdomyoma, and rhabdomyosarcoma.

Squamoid Eccrine Ductal Carcinoma: An Aggressive Mimicker of Squamous Cell Carcinoma.

Squamoid eccrine ductal carcinoma (SEDC) is an uncommon cutaneous adnexal malignancy that has the potential for an aggressive clinical course. The authors present a case of SEDC that resulted in widespread metastases and death. The clinical, histological, and immunohistochemical features of SEDC and several entities on the differential diagnosis are reviewed.

High-Velocity Paint Gun Injuries.

Cutaneous injuries due to industrial high-pressure paint guns are well-documented in the literature; however, the histologic characteristics are uncommonly described, and facial involvement has not been previously reported. Histopathologic features of paint gun injuries vary depending on the time since injection and type of material. Early lesions display an acute neutrophilic infiltrate, edema, and thrombosis, with varying degrees of skin, fat, and muscle necrosis. More developed lesions (120-192 hours after injury) have prominent histiocytes and fibrosis around necrotic foci, possibly with the pitfall of muscle regenerative giant cells that could be mistaken for sarcoma. Continuing inflammation, swelling, and resultant vascular compression could explain ongoing necrosis months after the accident. The histopathologic differential diagnosis in the absence of clinical history includes paint in an abrasion, foreign body reaction to tattoo, giant cell tumor of tendon sheath, and various neoplasms. If available, radiologic studies can substitute for clinical photographs to indicate the extent of injury. The radiologic differential, uninformed by history, may include calcific periarthritis, gouty tophus, and tumoral calcinosis. Seven cases of injury due to high-velocity paint guns are presented with 4 additional cases mimicking paint gun injury and with review of the literature.

Lupus erythematosus tumidus of the scalp masquerading as alopecia areata.

Lupus erythematosus tumidus (LET) is a unique subset of chronic cutaneous lupus erythematosus (CCLE) that generally presents as urticarialike papules and plaques with induration and erythema on the face, trunk, and upper extremities. Lesions rarely present on the scalp or below the waist. We report a unique case of LET on the scalp of a woman that presented clinically as alopecia areata. Resistance to the standard treatment for alopecia areata prompted a biopsy that proved the diagnosis.

Histopathologic diagnosis of multifactorial alopecia.

Establishing a definitive diagnosis for any form of alopecia can be challenging. Adding to the diagnostic complexity is the fact that many patients have more than one form of alopecia contributing to their hair loss. We conducted a review of 1360 consecutive scalp biopsy specimens submitted for the evaluation of scalp hair loss over a 16-month period, demonstrating that 12.5% of cases had a combination of diagnoses (multifactorial alopecia) accounting for their hair loss. An approach to the histopathologic diagnosis of multifactorial alopecia, particularly multiple forms of alopecia found in a single biopsy, is here presented.

Traumatic neuroma of the penis.

Traumatic neuromas are tumors produced by a reactive process to regenerate injured nerves that result in a disordered proliferation of nerve bundles. These tumors are usually related to previous surgery or trauma. We describe a case of traumatic neuroma on the penis of a 24-year-old man; the tumor was initially suspected to be a condyloma. A shave biopsy was both diagnostic and curative.