Basal cell carcinoma
The sections show nests of basaloid cells in the superficial dermis with peripheral palisading of the nuclei, and abundant mitoses. The nests demonstrate focal clefting with the surrounding myxoid stroma.
Dense superficial dermal collagen bundles running parallel to the dermal-epidermal junction are seen in association with loss of the rete ridges and mononuclear, perivascular inflammatory cells (dermal scar). The tumour is present in one of the tips (block A1).
Skin, scalp, excisional biopsy:
Basal cell carcinoma, see comment.
Comment: The tumour is present in one of the tips; thus, the lesion is at least closely excised.
SCC in situ, actinic keratosis
A. The sections show superficial skin with benign, underlying skeletal muscle. The skin shows full thickness nuclear atypia (including moderate-to-marked nuclear enlargement, nuclear hyperchromasia) at a site of ulceration and in a region with overlying hyperkeratosis (squamous cell carcinoma in situ). Several atypical mitoses are identified. The edge of the lesion shows nuclear changes, including hyperchromasia and nuclear enlargement, in the basal layer (actinic keratosis). Severe solar elastosis is present.
B. The sections show superficial skin with full thickness nuclear atypia (including mild-to-moderate nuclear enlargement, nuclear hyperchromasia) in a region with overlying hyperkeratosis (squamous cell carcinoma in situ). Mitoses and dyskeratotic cells are numerous. The edge of the lesion shows nuclear changes, including hyperchromasia and nuclear enlargement, in the basal layer (actinic keratosis). Solar elastosis is present.
A. Left upper lip, lesion, excision:
Squamous cell carcinoma in situ, resection margin close.
Severe solar elastosis.
B. Right dorsal wrist, lesion, excision:
Squamous cell carcinoma in situ.
The sections show an atypical spindle cell lesion in the deep dermis, with a storiform and fascicular pattern, marked nuclear pleomorphism and very high mitotic activity (129 mitoses / 10 HPF, field diameter 0.55 mm). The spindle cells have moderate-to-abundant partially vacuolated eosinophilic-to-amphophilic cytoplasm, ellipsoid-to-ovoid nuclei with coarse, irregular chromatin and, focally, nucleoli visible with the 10x objective. Atypical (malignant) multinucleated-cells are identified focally with abundant pale gray cytoplasm.
Benign dense thick collagen bundles are seen in the superficial dermis with associated loss of the rete ridges (dermal scar). Suture material and (reactive) foreign body-type giant cells are also seen.
Immunohistochemical staining show: -Positive staining of the tumour with: factor XIIIa (cytoplasmic), SMA (cytoplasmic - focal), WT1 (granular cytoplasmic - focal), CD10 (membranous/cytoplasmic), CD68 (cytoplasmic). -Negative staining of the tumour with: S100, p63, CD34, LMWK, CK5/6.
Forearm lesion, left, re-excision:
-PLEOMORPHIC UNDIFFERENTIATED SARCOMA OF THE SKIN (MALIGNANT FIBROUS HISTIOCYTOMA) WITH DEEP MARGIN FOCALLY POSITIVE, RE-EXCISION IS SUGGESTED.
The sections show thick collagen bundles in the dermis covered by a flat epidermis with basal hyperpigmentation (dermal scar). This is surrounded by a cellular, poorly demarcated, dermal-based spindle cell lesion with a storiform pattern. There is no significant atypia or mitotic activity. The lesion extends, focally, to the deep margin (block A5) and contains adipose tissue within it (honeycomb pattern).
Immunohistochemical stains show that the lesion is strongly CD34 positive and negative for factor XIIIa.
Skin, left abdomen, re-excision:
-DERMATOFIBROSARCOMA PROTUBERANS WITH POSITIVE DEEP MARGIN, RE-EXCISION SUGGESTED.