Metastatic colorectal cancer to a primary thyroid cancer.

BACKGROUND: Metastatic malignancy to the thyroid gland is generally uncommon due to an unfavourable local thyroid micro-environment which impairs the ability of metastatic cells to settle and thrive. Metastases to the thyroid gland have however been reported to occur occasionally particularly if there has been disruption to normal thyroid tissue architecture. CASE PRESENTATION: We report a patient with a history of surgically resected rectal adenocarcinoma who presents with a rising serum CEA level and an 18F-FDG PET scan positive thyroid nodule which was subsequently confirmed at surgery to be a focus of metastatic rectal adenocarcinoma within a primary poorly differentiated papillary thyroid carcinoma.Subsequent treatment involved right hemi-thyroidectomy, pulmonary wedge resection of oligometastatic metastatic colorectal cancer and chemotherapy. CONCLUSION: Metastatic rectal carcinoma to the thyroid gland and in particular to a primary thyroid malignancy is rare and unusual. Prognosis is likely to be more dependent on underlying metastatic disease rather than the primary thyroid malignancy hence primary treatments should be tailored towards treating and controlling metastatic disease and less emphasis placed on the primary thyroid malignancy.

Efficacy of imiquimod cream, 5%, for lentigo maligna after complete excision: a study of 43 patients.

OBJECTIVE: To determine the efficacy of imiquimod cream, 5%, in the treatment of lentigo maligna (LM). DESIGN: Open-label before-and-after interventional study. SETTING: A multidisciplinary melanoma clinic at a major tertiary hospital. PATIENTS: Forty-three patients with biopsy-proven LM of greater than 5 mm in diameter completed this study. INTERVENTIONS: Imiquimod cream, 5%, was applied to the lesion 5 days a week for 12 weeks. The original lesion was excised with a 5-mm margin. MAIN OUTCOME MEASURES: The primary outcome was histopathologic evidence of LM in the excision specimen assessed independently by 2 of 3 dermatopathologists. Visible inflammation during treatment and macroscopic clearance were recorded. RESULTS: When 5 of the 43 patients with discordant histopathologic assessment of the excision specimen were excluded, 20 of 38 patients (53% [95% confidence interval, 36%-69%]) demonstrated histopathologic clearance of LM after imiquimod treatment. Visible inflammation was significantly associated with histopathologic clearance (P = .04), but the positive predictive value was low (62%). Macroscopic clearance showed some association with histopathologic clearance (P = .11). Dermatopathologist concordance for all 43 specimens was substantial (κ = 0.77; 95% confidence interval, 0.57-0.96). CONCLUSIONS: Imiquimod cream, 5%, has limited efficacy in the treatment of LM when determined by histopathologic assessment of the entire treated area. The clinical signs of visible inflammation during treatment and apparent lesion clearance cannot be relied on to assess efficacy.

The impact of partial biopsy on histopathologic diagnosis of cutaneous melanoma: experience of an Australian tertiary referral service.

OBJECTIVE: To compare partial and excisional biopsy techniques in the accuracy of histopathologic diagnosis and microstaging of cutaneous melanoma. DESIGN: Prospective case series. SETTING: Tertiary referral, ambulatory care, institutional practice. Patients Consecutive cases from 1995 to 2006. Interventions Partial and excisional biopsy. Other factors considered were anatomic site, physician type at initial management, hypomelanosis, melanoma subtype, biopsy sample size, multiple biopsies, and tumor thickness. MAIN OUTCOME MEASURES: Histopathologic diagnosis (false-negative misdiagnosis-overall or with an adverse outcome-and false-positive misdiagnosis) and microstaging accuracy. Odds ratios (ORs) and 95% confidence intervals (CIs) obtained from multinomial logistic regression. RESULTS: Increased odds of histopathologic misdiagnosis were associated with punch biopsy (OR, 16.6; 95% CI, 10-27) (P < .001) and shave biopsy (OR, 2.6; 95% CI, 1.2-5.7) (P = .02) compared with excisional biopsy. Punch biopsy was associated with increased odds of misdiagnosis with an adverse outcome (OR, 20; 95% CI, 10-41) (P < .001). Other factors associated with increased odds of misdiagnosis included acral lentiginous melanoma (OR, 5.1; 95% CI, 2-13) (P < .001), desmoplastic melanoma (OR, 3.8; 95% CI, 1.1-13.0) (P = .03), and nevoid melanoma (OR, 28.4; 95% CI, 7-115) (P < .001). Punch biopsy (OR, 5.1; 95% CI, 3.4-7.6) (P < .001) and shave biopsy (OR, 2.3; 95% CI, 1.5-3.6) (P < .001) had increased odds of microstaging inaccuracy over excisional biopsy. Tumor thickness was the most important determinant of microstaging inaccuracy when partial biopsy was used (odds of significant microstaging inaccuracy increased 1.8-fold for every 1 mm increase in tumor thickness; 95% CI, 1.4-2.4) (P < .001). CONCLUSIONS: Among melanoma seen at a tertiary referral center, histopathologic misdiagnosis is more common for melanomas that have been assessed with punch and shave biopsy than with excisional biopsy. Regardless of biopsy method, adverse outcomes due to misdiagnosis may occur. However, such adverse events are more commonly associated with punch biopsy than with shave and excisional biopsy. The use of punch and shave biopsy also leads to increased microstaging inaccuracy.