Attending Dermatologist: Susan Massick, MD

Dermatopathologist: Catherine Chung, MD


69 yo Caucasian male with prior history of basal cell carcinomas and actinic keratoses presents with a three-month history of a fast-growing erythematous nodule with ulceration on his right scalp. (Figure 1) Further examination reveals palpable lymphadenopathy on his right cervical neck. A biopsy was performed, with surgical intervention performed.

One month after surgery, he presents with new additional pink erythematous nodules separate and posterior to the margin of his original surgery. (Figures 2 and 3) Despite intervention, he continues to have disease progression. (Figure 4)

Figure 1: Erythematous tender nodule with ulceration and hemorrhage. Arrow marks biopsy #1 site.

Figures 2 and 3: One month post op with new erythematous papules near original excision margin. Arrow marks biopsy #2 site.

Figure 4: Continued disease progression, photo taken 3 months after initial diagnosis.

Figure 5: Shave biopsy shows blue tumor lobules within the dermis.

Figure 6: Tumor cells are of uniform size with large nuclei and multiple small nucleoli, lending a speckled apperance, and scant cytoplasm. Numerous mitotic figures are present (arrows).

Figure 7: Tumor cells stain with CK20, many with a characteristic “perinuclear dot” (arrow).

What is your diagnosis?

  1. Amelanotic Melanoma
  2. Metastatic disease of unknown primary
  3. Sebaceous Carcinoma
  4. Merkel Cell Carcinoma
Merkel Cell Carcinoma